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Chen Z, Bian C, Liao K, Bishop C, Li Y. Validity and Reliability of a Phone App and Stopwatch for the Measurement of 505 Change of Direction Performance: A Test-Retest Study Design. Front Physiol 2021; 12:743800. [PMID: 34630164 PMCID: PMC8498103 DOI: 10.3389/fphys.2021.743800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 08/23/2021] [Indexed: 11/29/2022] Open
Abstract
Purpose: The aim of this study was to explore the validity and reliability of a phone app [named: change of direction (COD) timer] and stopwatches for the measurement of COD performance. Methods: Sixty-two youth basketball players (age: 15.9±1.4yrs., height: 178.8±11.0cm, and body mass: 70.0±14.1kg) performed six trials of 505 COD test (with the left side being the plant leg first, then the right side). The completion time was measured simultaneously via timing gates (with error correction processing algorithms), the phone app, and stopwatches. Results: There was an almost perfect correlation and agreement between timing gates and COD timer (r=0.978; SEE=0.035s; and LoA=−0.08~0.06s), but a lower correlation and agreement between timing gates and stopwatch (r=0.954; SEE=0.050s; and LoA=−0.17~0.04s) with statistical significance in completion time (ES=1.29, 95%CI: 1.15–1.43, p<0.01). The coefficient of variation revealed similar level of dispersion between the three timing devices (timing gates: 6.58%; COD timer: 6.32%; and stopwatch: 6.71%). Inter-observer reliability (ICC=0.991) and test-retest reliability (ICC=0.998) were excellent in COD timer, while the inter-observer reliability was lower (ICC=0.890) in the stopwatches. Conclusion: In the 505 COD test, the COD timer was able to provide a valid and reliable measurement. On the contrary, stopwatch was not recommended because of large error. Thus, if timing gates are unavailable, practitioners can adopt the COD timer app to assess 505 COD speed times.
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Affiliation(s)
- Zhili Chen
- School of Physical Education & Sport Training, Shanghai University of Sport, Shanghai, China
| | - Chao Bian
- School of Physical Education & Sport Training, Shanghai University of Sport, Shanghai, China
| | - Kaifang Liao
- School of Physical Education & Sport Training, Shanghai University of Sport, Shanghai, China
| | - Chris Bishop
- Faculty of Science and Technology, London Sport Institute, Middlesex University, London, United Kingdom
| | - Yongming Li
- School of Physical Education & Sport Training, Shanghai University of Sport, Shanghai, China.,China Institute of Sport Science, Beijing, China
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Nicholson B, Dinsdale A, Jones B, Till K. The Training of Medium- to Long-Distance Sprint Performance in Football Code Athletes: A Systematic Review and Meta-analysis. Sports Med 2021; 52:257-286. [PMID: 34499339 PMCID: PMC8803780 DOI: 10.1007/s40279-021-01552-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2021] [Indexed: 12/01/2022]
Abstract
Background Within the football codes, medium-distance (i.e., > 20 m and ≤ 40 m) and long-distance (i.e., > 40 m) sprint performance and maximum velocity sprinting are important capacities for success. Despite this, no research has identified the most effective training methods for enhancing medium- to long-distance sprint outcomes. Objectives This systematic review with meta-analysis aimed to (1) analyse the ability of different methods to enhance medium- to long-distance sprint performance outcomes (0–30 m, 0 to > 30 m, and the maximum sprinting velocity phase [Vmax]) within football code athletes and (2) identify how moderator variables (i.e., football code, sex, age, playing standard, phase of season) affected the training response. Methods We conducted a systematic search of electronic databases and performed a random-effects meta-analysis (within-group changes and pairwise between-group differences) to establish standardised mean differences (SMDs) with 95% confidence intervals and 95% prediction intervals. This identified the magnitude and direction of the individual training effects of intervention subgroups (sport only; primary, secondary, tertiary, and combined training methods) on medium- to long-distance sprint performance while considering moderator variables. Results In total, 60 studies met the inclusion criteria (26 with a sport-only control group), totalling 111 intervention groups and 1500 athletes. The within-group changes design reported significant performance improvements (small–moderate) between pre- and post-training for the combined, secondary (0–30 and 0 to > 30 m), and tertiary training methods (0–30 m). A significant moderate improvement was found in the Vmax phase performance only for tertiary training methods, with no significant effect found for sport only or primary training methods. The pairwise between-group differences design (experimental vs. control) reported favourable performance improvements (large SMD) for the combined (0 to > 30 m), primary (Vmax phase), secondary (0–30 m), and tertiary methods (all outcomes) when compared with the sport-only control groups. Subgroup analysis showed that the significant differences between the meta-analysis designs consistently demonstrated a larger effect in the pairwise between-group differences than the within-group change. No individual training mode was found to be the most effective. Subgroup analysis identified that football code, age, and phase of season moderated the overall magnitude of training effects. Conclusions This review provides the first systematic review and meta-analysis of all sprint performance development methods exclusively in football code athletes. Secondary, tertiary, and combined training methods appeared to improve medium-long sprint performance of football code athletes. Tertiary training methods should be implemented to enhance Vmax phase performance. Nether sport-only nor primary training methods appeared to enhance medium to long sprint performance. Performance changes may be attributed to either adaptations specific to the acceleration or Vmax phases, or both, but not exclusively Vmax. Regardless of the population characteristics, sprint performance can be enhanced by increasing either the magnitude or the orientation of force an athlete can generate in the sprinting action, or both. Trial Registration OSF registration https://osf.io/kshqn/. Supplementary Information The online version contains supplementary material available at 10.1007/s40279-021-01552-4.
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Affiliation(s)
- Ben Nicholson
- Carnegie Applied Rugby Research (CARR) Centre, Carnegie School of Sport, Leeds Beckett University, Headingley Campus, Leeds, LS6 3QS, UK.
| | - Alex Dinsdale
- Carnegie Applied Rugby Research (CARR) Centre, Carnegie School of Sport, Leeds Beckett University, Headingley Campus, Leeds, LS6 3QS, UK
| | - Ben Jones
- Carnegie Applied Rugby Research (CARR) Centre, Carnegie School of Sport, Leeds Beckett University, Headingley Campus, Leeds, LS6 3QS, UK.,Leeds Rhinos Rugby League Club, Leeds, UK.,England Performance Unit, The Rugby Football League, Leeds, UK.,School of Science and Technology, University of New England, Armidale, NSW, Australia.,Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, The University of Cape Town and the Sports Science Institute of South Africa, Cape Town, South Africa
| | - Kevin Till
- Carnegie Applied Rugby Research (CARR) Centre, Carnegie School of Sport, Leeds Beckett University, Headingley Campus, Leeds, LS6 3QS, UK.,Leeds Rhinos Rugby League Club, Leeds, UK
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Reactive diving and sprinting performances in soccer goalkeepers improved by caffeine consumption and post-activation performance enhancement. GERMAN JOURNAL OF EXERCISE AND SPORT RESEARCH 2021. [DOI: 10.1007/s12662-021-00746-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Pérez-Chirinos Buxadé C, Fernández-Valdés B, Morral-Yepes M, Tuyà Viñas S, Padullés Riu JM, Moras Feliu G. Validity of a Magnet-Based Timing System Using the Magnetometer Built into an IMU. SENSORS 2021; 21:s21175773. [PMID: 34502664 PMCID: PMC8433996 DOI: 10.3390/s21175773] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 11/16/2022]
Abstract
Inertial measurement units (IMUs) represent a technology that is booming in sports right now. The aim of this study was to evaluate the validity of a new application on the use of these wearable sensors, specifically to evaluate a magnet-based timing system (M-BTS) for timing short-duration sports actions using the magnetometer built into an IMU in different sporting contexts. Forty-eight athletes (22.7 ± 3.3 years, 72.2 ± 10.3 kg, 176.9 ± 8.5 cm) and eight skiers (17.4 ± 0.8 years, 176.4 ± 4.9 cm, 67.7 ± 2.0 kg) performed a 60-m linear sprint running test and a ski slalom, respectively. The M-BTS consisted of placing several magnets along the course in both contexts. The magnetometer built into the IMU detected the peak-shaped magnetic field when passing near the magnets at a certain speed. The time between peaks was calculated. The system was validated with photocells. The 95% error intervals for the total times were less than 0.077 s for the running test and 0.050 s for the ski slalom. With the M-BTS, future studies could select and cut the signals belonging to the other sensors that are integrated in the IMU, such as the accelerometer and the gyroscope.
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Affiliation(s)
- Carla Pérez-Chirinos Buxadé
- National Institute of Physical Education of Catalonia (INEFC), University of Barcelona (UB), 08038 Barcelona, Spain; (C.P.-C.B.); (B.F.-V.); (M.M.-Y.); (S.T.V.); (J.M.P.R.)
| | - Bruno Fernández-Valdés
- National Institute of Physical Education of Catalonia (INEFC), University of Barcelona (UB), 08038 Barcelona, Spain; (C.P.-C.B.); (B.F.-V.); (M.M.-Y.); (S.T.V.); (J.M.P.R.)
- School of Health Sciences, TecnoCampus, Pompeu Fabra University, 08302 Barcelona, Spain
| | - Mónica Morral-Yepes
- National Institute of Physical Education of Catalonia (INEFC), University of Barcelona (UB), 08038 Barcelona, Spain; (C.P.-C.B.); (B.F.-V.); (M.M.-Y.); (S.T.V.); (J.M.P.R.)
| | - Sílvia Tuyà Viñas
- National Institute of Physical Education of Catalonia (INEFC), University of Barcelona (UB), 08038 Barcelona, Spain; (C.P.-C.B.); (B.F.-V.); (M.M.-Y.); (S.T.V.); (J.M.P.R.)
| | - Josep Maria Padullés Riu
- National Institute of Physical Education of Catalonia (INEFC), University of Barcelona (UB), 08038 Barcelona, Spain; (C.P.-C.B.); (B.F.-V.); (M.M.-Y.); (S.T.V.); (J.M.P.R.)
| | - Gerard Moras Feliu
- National Institute of Physical Education of Catalonia (INEFC), University of Barcelona (UB), 08038 Barcelona, Spain; (C.P.-C.B.); (B.F.-V.); (M.M.-Y.); (S.T.V.); (J.M.P.R.)
- Correspondence:
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Bellinger P, Bourne MN, Duhig S, Lievens E, Kennedy B, Martin A, Cooper C, Tredrea M, Rice H, Derave W, Minahan C. Relationships between Lower Limb Muscle Characteristics and Force-Velocity Profiles Derived during Sprinting and Jumping. Med Sci Sports Exerc 2021; 53:1400-1411. [PMID: 33481483 DOI: 10.1249/mss.0000000000002605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aimed to identify the relationships between lower limb muscle characteristics and mechanical variables derived from the vertical (jumping) and horizontal (sprinting) force-velocity-power (FVP) profiles. METHODS Nineteen subelite male rugby league players performed a series of squat jumps and linear 30-m sprints to derive the vertical and horizontal FVP profiles, respectively. The theoretical maximal force (F0), velocity (V0), and power (Pmax) were derived from both the vertical (i.e., vF0, vV0, and vPmax) and the horizontal (i.e., hF0, hV0, and hPmax) FVP profiles. Vastus lateralis (VL), biceps femoris long head, and gastrocnemius medialis (GM) and lateralis muscle fascicle length, pennation angle, and thickness were measured using B-mode ultrasonography. Magnetic resonance imaging was used to calculate volumes of major lower limb muscles, whereas proton magnetic resonance spectroscopy was used to quantify the carnosine content of the GM to estimate muscle fiber typology. RESULTS Variation in vPmax was best explained by GM muscle fiber typology (i.e., greater estimated proportion of Type II fibers) and VL volume (adjusted r2 = 0.440, P = 0.006), whereas adductor and vastus medialis volume and GM muscle fiber typology explained the most variation in hPmax (adjusted r2 = 0.634, P = 0.032). Rectus femoris and VL volume explained variation in vF0 (r2 = 0.430, P = 0.008), whereas adductor and vastus medialis volume explained variation in hF0 (r2 = 0.432, P = 0.007). Variations in vV0 and hV0 were best explained by GM muscle fiber typology (adjusted r2 = 0.580, P < 0.001) and GM muscle fiber typology and biceps femoris short head volume (adjusted r2 = 0.590, P < 0.001), respectively. CONCLUSION Muscle fiber typology and muscle volume are strong determinants of maximal muscle power in jumping and sprinting by influencing the velocity- and force-oriented mechanical variables.
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Affiliation(s)
| | | | | | - Eline Lievens
- Department of Movement and Sports Sciences, Ghent University, Ghent, BELGIUM
| | | | - Andrew Martin
- Griffith Sports Science, Griffith University, Gold Coast, Southport, Queensland, AUSTRALIA
| | - Christopher Cooper
- Griffith Sports Science, Griffith University, Gold Coast, Southport, Queensland, AUSTRALIA
| | - Matthew Tredrea
- Department of Rehabilitation, Nutrition and Sport, La Trobe University College of Science Health and Engineering, Nutrition and Sport, Bundoora, AUSTRALIA
| | - Hal Rice
- Qscan Radiology, Queensland, AUSTRALIA
| | - Wim Derave
- Department of Movement and Sports Sciences, Ghent University, Ghent, BELGIUM
| | - Clare Minahan
- Griffith Sports Science, Griffith University, Gold Coast, Southport, Queensland, AUSTRALIA
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Perez J, Guilhem G, Brocherie F. Truncated Estimation of Skating Force-Velocity Profiling When Using High-Speed Video-Based Methods Compared to Radar-Derived Processing. Front Bioeng Biotechnol 2021; 9:661744. [PMID: 34249880 PMCID: PMC8264440 DOI: 10.3389/fbioe.2021.661744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 06/01/2021] [Indexed: 11/30/2022] Open
Abstract
This study aimed to compare the force-velocity mechanical variables derived from high-speed video- and radar-based method during forward skating sprint in ice hockey. Thirteen elite female ice hockey players performed two 40-m forward skating sprints to determine, in the horizontal plane, maximal velocity reached (Vmax), relative maximal theoretical force (F0), maximal theoretical velocity (V0), relative maximal power (Pmax), linear slope of the force-velocity relationship (FV slope), maximal value of the ratio of force (RFmax) and index of force application technique (Drf). Two different high-speed video-based methods adding a time shift (ST-TS) or not (ST) were used and independently compared to the radar-derived method. ST and ST-TS showed significant mean differences (all p < 0.002) compared to radar-derived processing for all variables except for V0 (p = 0.26) and Vmax (p = 0.13) inferred from ST. In reference to radar-derived variables, ST-TS significantly induced larger lower values compared to radar of the main forward skating sprint determinants (Pmax, F0, RFmax and Drf) and moderate-to-large overestimation for velocity variables (V0 and Vmax). Correlations between ST or ST-TS and radar-derived methods ranged from trivial for velocity variables to very large for force and power variables. Consequently, practitioners must be aware that using such high-speed video-based methods would permit to determine mechanical variables at the cost of much lower accuracy and reliability than the radar-derived method.
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Affiliation(s)
- Jerome Perez
- French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA 7370), Paris, France
- French Ice Hockey Federation, Cergy, France
| | - Gaël Guilhem
- French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA 7370), Paris, France
| | - Franck Brocherie
- French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA 7370), Paris, France
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New photocell timing gates for measuring the maximum velocity of futsal players. SPORT SCIENCES FOR HEALTH 2021. [DOI: 10.1007/s11332-021-00783-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Crossing the Golden Training Divide: The Science and Practice of Training World-Class 800- and 1500-m Runners. Sports Med 2021; 51:1835-1854. [PMID: 34021488 PMCID: PMC8363530 DOI: 10.1007/s40279-021-01481-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2021] [Indexed: 11/24/2022]
Abstract
Despite an increasing amount of research devoted to middle-distance training (herein the 800 and 1500 m events), information regarding the training methodologies of world-class runners is limited. Therefore, the objective of this review was to integrate scientific and best practice literature and outline a novel framework for understanding the training and development of elite middle-distance performance. Herein, we describe how well-known training principles and fundamental training characteristics are applied by world-leading middle-distance coaches and athletes to meet the physiological and neuromuscular demands of 800 and 1500 m. Large diversities in physiological profiles and training emerge among middle-distance runners, justifying a categorization into types across a continuum (400–800 m types, 800 m specialists, 800–1500 m types, 1500 m specialists and 1500–5000 m types). Larger running volumes (120–170 vs. 50–120 km·week−1 during the preparation period) and higher aerobic/anaerobic training distribution (90/10 vs. 60/40% of the annual running sessions below vs. at or above anaerobic threshold) distinguish 1500- and 800-m runners. Lactate tolerance and lactate production training are regularly included interval sessions by middle-distance runners, particularly among 800-m athletes. In addition, 800-m runners perform more strength, power and plyometric training than 1500-m runners. Although the literature is biased towards men and “long-distance thinking,” this review provides a point of departure for scientists and practitioners to further explore and quantify the training and development of elite 800- and 1500-m running performance and serves as a position statement for outlining current state-of-the-art middle-distance training recommendations.
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Boone JB, VanDusseldorp TA, Feito Y, Mangine GT. Relationships Between Sprinting, Broad Jump, and Vertical Jump Kinetics Are Limited in Elite, Collegiate Football Athletes. J Strength Cond Res 2021; 35:1306-1316. [PMID: 33900263 DOI: 10.1519/jsc.0000000000004008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Boone, JB, VanDusseldorp, TA, Feito, Y, and Mangine, GT. Relationships between sprinting, broad jump, and vertical jump kinetics are limited in elite, collegiate football athletes. J Strength Cond Res 35(5): 1306-1316, 2021-To evaluate the relationships and agreement in kinetics measured during a 10-yd sprint, a standing broad jump (SBJ), and a vertical jump (VJ), 73 collegiate football players (22.3 ± 0.8 years, 188 ± 7 cm, 113 ± 23 kg) volunteered for this cross-sectional study over a 3-year period. At the beginning of each athlete's off-season training phase and after a standard warm-up, each athlete completed 2-3 maximal trials of each test while tethered to a robotic, cable-resistance device (10-yd sprint and SBJ) or a linear position transducer (VJ alone). Force (N), velocity (m·s-1), and power (W) were measured during the first 2 steps, acceleration phase (units·step-1), and entire 10-yd sprint, and the entire SBJ and VJ. Spearman and partial correlations (controlling for stature) revealed small-to-moderate relationships (r = -0.30 to -0.34) between the second sprinting step and VJ force. Small negative relationships were also noted between sprinting and VJ force and power, but not when controlling for height. Agreement was determined by examining relationships between the differences in and averaged kinetics measured on each test. Trivial-to-small relationships (r < 0.29) were observed between sprinting (first step and 10-yd) and VJ velocity, and between VJ and SBJ velocity, although coefficient of variation (CV) ranged between 64 and 104%. All other relationships ranged from moderate-to-practically perfect with CVs exceeding 500%. Although some relationships exist between sprinting and jumping kinetics, their agreement is variable. These data suggest that coaches and athletes should not use one of these assessments in place of, or to predict performance in, the other assessments.
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Affiliation(s)
- Joseph B Boone
- Exercise Science and Sport Management, Kennesaw State University, Kennesaw, Georgia
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Dugdale JH, Sanders D, Myers T, Williams AM, Hunter AM. Progression from youth to professional soccer: A longitudinal study of successful and unsuccessful academy graduates. Scand J Med Sci Sports 2021; 31 Suppl 1:73-84. [PMID: 33871087 DOI: 10.1111/sms.13701] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/03/2020] [Accepted: 04/23/2020] [Indexed: 11/30/2022]
Abstract
To optimize use of available resources, professional academies develop strategies to assess, monitor, and evaluate players as they progress through adolescence toward adulthood. However, few published reports exist using longitudinal study designs to examine performance throughout adolescence and the transition from youth to professional soccer. We examined differences in the age of player recruitment alongside longitudinal performance differences on field-based fitness tests of successful vs. unsuccessful graduates across the entire age spectrum recruited by a professional soccer academy. Altogether, 537 youth soccer players volunteered to participate. We recorded the age of recruitment, biannual fitness test performance, and subsequent success in attaining a senior professional contract at the club across a period of 12 years. Only 53 (10%) of players were successful in obtaining a professional contract, with 68% of players who became professional being recruited at 12 years of age or older. Individuals recruited at an earlier age did not display a higher probability of success in attaining a professional contract. Bayesian regression models reported a consistent interaction between age and group for data on all performance measures. Moreover, "successful" academy graduates only physically outperformed their "unsuccessful" counterparts from age ~13-14 years onward, with either no differences in performance, or performance on physical fitness tests favoring "unsuccessful" players prior to this age. Findings suggest that high achievers during childhood and early adolescence may not develop into successful senior professionals, raising concerns about the predictive utility of talent identification models.
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Affiliation(s)
- James H Dugdale
- Physiology Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, UK
| | - Dajo Sanders
- Department of Human Movement Science, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Tony Myers
- Sport, Physical Activity and Health Research Centre, Newman University, Birmingham, UK
| | - A Mark Williams
- Department of Health, Kinesiology, and Recreation, University of Utah, Salt Lake City, UT, USA
| | - Angus M Hunter
- Physiology Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, UK
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Fischer-Sonderegger K, Taube W, Rumo M, Tschopp M. How far from the gold standard? Comparing the accuracy of a Local Position Measurement (LPM) system and a 15 Hz GPS to a laser for measuring acceleration and running speed during team sports. PLoS One 2021; 16:e0250549. [PMID: 33891640 PMCID: PMC8064559 DOI: 10.1371/journal.pone.0250549] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 04/09/2021] [Indexed: 11/18/2022] Open
Abstract
PURPOSE This study compared the validity and inter- and intra-unit reliability of local (LPM) and global (GPS) position measurement systems for measuring acceleration during team sports. METHODS Devices were attached to a remote-controlled car and validated against a laser. Mean percentage biases (MPBs) of maximal acceleration (amax) and maximal running speed (vmax) were used to measure validity. Mean between-device and mean within-device standard deviations of the percentage biases (bd-SDs and wd-SDs) of amax and vmax were used to measure inter- and intra-unit reliability, respectively. RESULTS Both systems tended to underestimate amax similarly (GPS: -61.8 to 3.5%; LPM: -53.9 to 9.6%). The MPBs of amax were lower in trials with unidirectional linear movements (GPS: -18.8 to 3.5%; LPM: -11.2 to 9.6%) than in trials with changes of direction (CODs; GPS: -61.8 to -21.1%; LPM: -53.9 to -35.3%). The MPBs of vmax (GPS: -3.3 to -1.0%; LPM: -12.4 to 1.5%) were lower than those of amax. The bd-SDs and the wd-SDs of amax were similar for both systems (bd-SDs: GPS: 2.8 to 12.0%; LPM 3.7 to 15.3%; wd-SDs: GPS: 3.7 to 28.4%; LPM: 5.3 to 27.2%), whereas GPS showed better bd-SDs of vmax than LPM. CONCLUSION The accuracy depended strongly on the type of action measured, with CODs displaying particularly poor validity, indicating a challenge for quantifying training loads in team sports.
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Affiliation(s)
- Karin Fischer-Sonderegger
- Swiss Federal Institute of Sport Magglingen SFISM, Section for Elite Sport, Magglingen, Switzerland
- Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland
- * E-mail:
| | - Wolfgang Taube
- Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland
| | - Martin Rumo
- Swiss Federal Institute of Sport Magglingen SFISM, Section for Elite Sport, Magglingen, Switzerland
| | - Markus Tschopp
- Swiss Federal Institute of Sport Magglingen SFISM, Section for Elite Sport, Magglingen, Switzerland
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Martins PC, Teixeira AS, Guglielmo LGANTONACCI, Francisco JS, Silva DAS, Nakamura FY, de Lima LRA. Phase Angle Is Related to 10 m and 30 m Sprint Time and Repeated-Sprint Ability in Young Male Soccer Players. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:4405. [PMID: 33919220 PMCID: PMC8122489 DOI: 10.3390/ijerph18094405] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/18/2021] [Accepted: 03/20/2021] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To examine the association between phase angle (PhA) and bioelectrical impedance vector analysis (BIVA) and components of physical performance in male youth soccer players. DESIGN Cross-sectional. METHODS Sixty-two players from two professional soccer academies were recruited. Electrical bioimpedance was used to obtain the PhA and BIVA. Body fat (BF) and lean soft tissue mass (LSTM) were measured by dual-energy X-ray absorptiometry. All players completed physical tests including the standing long jump (SLJ), Carminatti's test (peak speed at the end of the test, PST-CAR), 10 m and 30 m straight-line sprints, and repeated-sprint ability (RSA) test (RSAbest and RSAmean times). RESULTS Adjusting for chronological age, BF, and LSTM, multiple regression analysis outputs showed that PhA remained inversely related to RSAmean (β = -0.362; p < 0.001), RSAbest (β = -0.239; p = 0.020), 10 m (β = -0.379; p = 0.012), and 30 m (β = -0.438; p < 0.001) sprint times, while the association with PST-CAR and SLJ performance were statistically non-significant. In addition, BIVA showed that differences in confidence ellipses were found between athletes in the reference population and the study sample (p < 0.05). The tolerance ellipses indicated that the athletes in the present study had more total body water (TCW) and lower proportions of intracellular water (ICW) to extracellular water (ECW). The reference population had more TCW and ICW/ECW. CONCLUSIONS Our results suggest that young soccer players with higher PhA values, indicating better cell integrity and functionality, have better performance in typical anaerobic running activities, such as sprinting speed and RSA performance, adjusted to age and body composition characteristics.
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Affiliation(s)
- Priscila Custódio Martins
- Research Center in Kinanthropometry and Human Performance, Sports Center, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil; (J.S.F.); (D.A.S.S.)
| | - Anderson Santiago Teixeira
- Physical Effort Laboratory, Sports Center, Federal University of Santa Catarina, Florianópolis 88040-900, SC, Brazil; (A.S.T.); (L.G.A.G.)
- Research Group for Development of Football and Futsal, Sports Center, Federal University of Santa Catarina, Florianópolis 88040-900, SC, Brazil
| | - Luiz Guilherme ANTONACCI Guglielmo
- Physical Effort Laboratory, Sports Center, Federal University of Santa Catarina, Florianópolis 88040-900, SC, Brazil; (A.S.T.); (L.G.A.G.)
| | - Juliana Sabino Francisco
- Research Center in Kinanthropometry and Human Performance, Sports Center, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil; (J.S.F.); (D.A.S.S.)
| | - Diego Augusto Santos Silva
- Research Center in Kinanthropometry and Human Performance, Sports Center, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil; (J.S.F.); (D.A.S.S.)
| | - Fábio Yuzo Nakamura
- Associate Graduate Program in Physical Education UPE/UFPB, João Pessoa 58051-900, PB, Brazil;
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63
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Needham L, Evans M, Cosker DP, Colyer SL. Can Markerless Pose Estimation Algorithms Estimate 3D Mass Centre Positions and Velocities during Linear Sprinting Activities? SENSORS 2021; 21:s21082889. [PMID: 33924266 PMCID: PMC8074772 DOI: 10.3390/s21082889] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/01/2021] [Accepted: 04/14/2021] [Indexed: 11/16/2022]
Abstract
The ability to accurately and non-invasively measure 3D mass centre positions and their derivatives can provide rich insight into the physical demands of sports training and competition. This study examines a method for non-invasively measuring mass centre velocities using markerless human pose estimation and Kalman smoothing. Marker (Qualysis) and markerless (OpenPose) motion capture data were captured synchronously for sprinting and skeleton push starts. Mass centre positions and velocities derived from raw markerless pose estimation data contained large errors for both sprinting and skeleton pushing (mean ± SD = 0.127 ± 0.943 and -0.197 ± 1.549 m·s-1, respectively). Signal processing methods such as Kalman smoothing substantially reduced the mean error (±SD) in horizontal mass centre velocities (0.041 ± 0.257 m·s-1) during sprinting but the precision remained poor. Applying pose estimation to activities which exhibit unusual body poses (e.g., skeleton pushing) appears to elicit more erroneous results due to poor performance of the pose estimation algorithm. Researchers and practitioners should apply these methods with caution to activities beyond sprinting as pose estimation algorithms may not generalise well to the activity of interest. Retraining the model using activity specific data to produce more specialised networks is therefore recommended.
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64
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Parrini S, Rossini G, Nebiolo B, Airale M, Franceschi A, Cugliari G, Deregibus A, Castroflorio T. Variations in athletic performance with occlusal splint in track and field athletes: a randomized clinical trial. J Sports Med Phys Fitness 2021; 62:375-381. [PMID: 33871235 DOI: 10.23736/s0022-4707.21.12081-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Several studies have been proposed with the aim to demonstrate correlations between the dento-mandibular apparatus and the skeletal muscle system of the human body even in regions distant from the oral cavity. However, a definite conclusion cannot be drawn. The aim of this paper is to demonstrate a possible correlation between dental occlusion and sport performances in track and field athletes. METHODS 16 track and field athletes were enrolled for the study and were randomly divided in three groups: Untreated control group, Placebo group (with a lower plaque without occlusal coverage) and Treated group (with occlusal splint). Changes in sprint and jump performance were assessed on a weekly basis for 5 consecutive weeks, during which athletes had to wear oral devices, except for the first week of baseline, for at least 3 trainings lasting 2 hours per week. All participants performed the countermovement jump (CMJ), the drop jump (DJ), the 10m and 30m sprint tests, always on the same day on the week. RESULTS No statistically significant difference resulted between Control group and Placebo group and between Control group and Treated group. However it was possible to observe a clinical improvement of measurements obtained, especially for CMJ, 10m and 30m sprint tests. No variation neither statistical neither clinical was observed in DJ test analysis. CONCLUSIONS Even if statistically it was not possible to demonstrate an improvement in sport performance, most of the athlete analyzed showed better results during training session with occlusal splint compared to athlete without occlusal splint, in countermovement jump, in 10m and 30m sprint tests.
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Affiliation(s)
- Simone Parrini
- Department of Surgical Sciences, CIR Dental School, University of Turin, Turin, Italy -
| | - Gabriele Rossini
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, University of Turin, Turin, Italy
| | - Bianca Nebiolo
- Department of Surgical Sciences, CIR Dental School, University of Turin, Turin, Italy
| | - Marco Airale
- Eracle Academy, Metropolitan City of Turin, Turin, Italy
| | - Alberto Franceschi
- Eracle Academy, Metropolitan City of Turin, Turin, Italy.,Research Center in Sports Sciences, Health and Human Development, CIDESD, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal
| | | | - Andrea Deregibus
- Department of Surgical Sciences, CIR Dental School, University of Turin, Turin, Italy
| | - Tommaso Castroflorio
- Department of Surgical Sciences, CIR Dental School, University of Turin, Turin, Italy
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65
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Baena-Raya A, Soriano-Maldonado A, Rodríguez-Pérez MA, García-de-Alcaraz A, Ortega-Becerra M, Jiménez-Reyes P, García-Ramos A. The force-velocity profile as determinant of spike and serve ball speed in top-level male volleyball players. PLoS One 2021; 16:e0249612. [PMID: 33798256 PMCID: PMC8018657 DOI: 10.1371/journal.pone.0249612] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/19/2021] [Indexed: 11/19/2022] Open
Abstract
Understanding the relationship between mechanical variables derived from actions such as jumping, sprinting, or ballistic bench press throwing and sport-specific performance moves is of scientific and practical interest for strength and conditioning coaches for improving training programs. We examined the association between mechanical variables derived from the force-velocity (FV) profiles of the aforementioned actions and spike and serve ball speeds in elite volleyball players. Twenty-two male elite volleyball players (age: 24.3 ± 4.5 years; height: 1.89 ± 0.06 m; body mass: 86.3 ± 8.6 kg) were tested in two sessions. Squatting, sprinting, and bench press throwing FV profiles were determined in the first session, while spike and serve ball speeds were assessed in the second session. The theoretical maximal force (F0) of vertical jumping, the theoretical maximal velocity of sprinting, and the F0 of bench press throwing in ascending order, were strongly associated (rs range 0.53-0.84; p<0.05) with spike and serve ball speeds. These mechanical variables explained 20%-36% of the variability in spike and serve ball speeds, with a greater influence on the serve speed. These results suggest that assessing jumping, sprinting, and bench press throwing force-velocity profiles might help provide player-specific training programs and optimize performance in these technical-tactical actions in male elite volleyball players.
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Affiliation(s)
- Andrés Baena-Raya
- Department of Education, Faculty of Education Sciences, University of Almería, Almería, Spain
- SPORT Research Group (CTS-1024), CERNEP Research Center, University of Almería, Almería, Spain
| | - Alberto Soriano-Maldonado
- Department of Education, Faculty of Education Sciences, University of Almería, Almería, Spain
- SPORT Research Group (CTS-1024), CERNEP Research Center, University of Almería, Almería, Spain
| | - Manuel A. Rodríguez-Pérez
- Department of Education, Faculty of Education Sciences, University of Almería, Almería, Spain
- SPORT Research Group (CTS-1024), CERNEP Research Center, University of Almería, Almería, Spain
- * E-mail:
| | - Antonio García-de-Alcaraz
- Department of Education, Faculty of Education Sciences, University of Almería, Almería, Spain
- SPORT Research Group (CTS-1024), CERNEP Research Center, University of Almería, Almería, Spain
| | - Manuel Ortega-Becerra
- Physical Performance & Sports Research Center, Pablo de Olavide University, Seville, Spain
| | | | - Amador García-Ramos
- Department of Physical Education and Sport, Faculty of Sport Science, University of Granada, Granada, Spain
- Department of Sports Sciences and Physical Conditioning, Faculty of Education, Universidad Católica de la Santísima Concepción, Concepción, Chile
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Martínez-Cabrera FI, Núñez-Sánchez FJ, Losada J, Otero-Esquina C, Sánchez H, De Hoyo M. Use of Individual Relative Thresholds to Assess Acceleration in Young Soccer Players According to Initial Speed. J Strength Cond Res 2021; 35:1110-1118. [PMID: 30507732 DOI: 10.1519/jsc.0000000000002902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Martínez-Cabrera, FI, Núñez-Sánchez, FJ, Losada, J, Otero-Esquina, C, Sánchez, H, and De Hoyo, M. Use of individual relative thresholds to assess acceleration in young soccer players according to initial speed. J Strength Cond Res 35(4): 1110-1118, 2021-The aims of the current study were (a) to analyze the characteristics of acceleration efforts using individual relative thresholds according to the initial speed during official matches in elite young soccer players according to player position and (b) to compare the differences between absolute and relative thresholds in assessing high-intensity acceleration. Player acceleration profiles were assessed using an individual relative threshold based on their acceleration capacity at different initial speeds (standing, 6, 10.8, and 15 km·h-1), and the number of accelerations (>75% of the maximal acceleration) performed during soccer matches was divided into 3 categories attending to the initial speed. (S1 = 0-7 km·h-1; S2 = 7.1-14 km·h-1; and S3 = ≥14.1 km·h-1). Within-group analyses showed that the number of accelerations performed in each category was higher when the effort started from a static or walking position than at moderate- or high-intensity running (S1 > S2 > S3; very likely to almost certain). Between-group analyses revealed substantial differences between some playing positions according to initial speed. In S1 and S3, central defenders had the lowest number of accelerations (likely to almost certain), whereas midfielders had the greatest number of high-intensity accelerations in S1 and S2. There were also substantial differences between the other playing positions (possibly to almost certain). Regarding relative and absolute thresholds (>3 m·s-2), the results showed that absolute threshold overestimated the number of high-intensity accelerations compared with the individual relative threshold in S1 and underestimated the results in S2 and S3 (almost certain). The use of an individual relative threshold to measure acceleration demands allows to distinguish between the numbers of accelerations in function of the initial speed and playing positions. In addition, the absolute acceleration threshold could overestimate or underestimate the acceleration demands in young soccer players as a function of the initial speed. Then, the absolute acceleration thresholds should be taken with caution in the assessment of acceleration activities.
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Affiliation(s)
| | | | - Jose Losada
- CEDIFA, Andalusian Football Federation, Seville, Spain
| | | | - Hugo Sánchez
- Fitness Section, Sevilla Football Club, Seville, Spain; and
| | - Moisés De Hoyo
- Department of Physical Education and Sport, University of Seville, Seville, Spain
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The Effect of Autoregulated Flywheel and Traditional Strength Training on Training Load Progression and Motor Skill Performance in Youth Athletes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18073479. [PMID: 33801621 PMCID: PMC8038127 DOI: 10.3390/ijerph18073479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 12/01/2022]
Abstract
Background: The effects of flywheel resistance training (FRT) on youth are relatively unknown. The aim of this study was to compare the effects of autoregulated FRT with traditional strength training (TST) on jumping, running performance and resistance training load progression in youth athletes. Thirty youth athletes (11.8 ± 0.9 yr) were matched for peak height velocity (PHV) status and block-randomised into two groups: FRT (n = 15, PHV −0.8 ± 1.6) and TST (n = 15, PHV −0.8 ± 1.5). Twelve resistance training sessions over a six-week intervention with flywheel or barbell squats were performed using autoregulated load prescription. Squat jump (SJ); countermovement jump (CMJ); and 10 m, 20 m and 30 m sprints were assessed pre- and post-intervention. The external load increased similarly for FRT and TST (z = 3.8, p = 0.06). SJ increased for both groups (p < 0.05) but running performance was unaffected (p > 0.05). Conclusions: FRT resulted in similar load progression and motor skill development in youth athletes as TST, but the perceived exertion was less. Autoregulation is a practical method for adjusting training load during FRT and should be considered as an alternative to autoregulated TST.
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Dobbin N, Cushman S, Clarke J, Batsford J, Twist C. Differences in the vertical and horizontal force-velocity profile between academy and senior professional rugby league players, and the implications for strength and speed training. J Sports Med Phys Fitness 2021; 62:184-191. [PMID: 33768773 DOI: 10.23736/s0022-4707.21.12036-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND This study compared the vertical and horizontal force-velocity (FV) profile of academy and senior rugby league players. METHODS Nineteen senior and twenty academy players from one professional club participated in this study. The vertical FV profile was determined using a series of loaded squat jumps (0.4 to 80 kg) with jump height recorded. The horizontal FV profile involved a 30-m over-ground sprint with split times recorded at 5, 10, 15, 20 and 30 m. Theoretical maximal force (F0), velocity (V0) and power (Pmax), optimal F0 and V0, and activity specific variables (e.g. vertical FV imbalance) were determined. RESULTS Absolute F0 and Pmax from the vertical and horizontal profile were moderately different between groups (standardised mean difference (SMD) = 0.64-1.20, P <0.001-0.026), whilst for V0, differences were small (SMD = 0.33-0.41, P = 0.149-0.283). Differences in relative F0, Pmax and optimal F0 during both assessments were trivial to moderate (SMD = 0.03-0.82, P = 0.021-0.907). CONCLUSIONS These results highlight senior and academy players present with different FV profiles and highlight some potential developmental opportunities for senior and academy rugby league players that sport scientists, strength and conditioning and rugby coaches can implement when designing programmes and considering long-term athlete development.
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Affiliation(s)
- Nick Dobbin
- Department of Health Professions, Manchester Metropolitan University, Manchester, UK -
| | - Simon Cushman
- Department of Sport and Public Services, Reaseheath College, Reaseheath, UK
| | - Jon Clarke
- Performance Department, Rugby Football Union, Twickenham, UK
| | - Jakes Batsford
- Performance Department, Salford Red Devils Rugby League Football Club, Salford, UK
| | - Craig Twist
- Department of Sport and Exercise Science, University of Chester, Chester, UK
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69
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Bautista IJ, Vicente-Mampel J, Baraja-Vegas L, Segarra V, Martín F, Van Hooren B. The effects of the Nordic hamstring exercise on sprint performance and eccentric knee flexor strength: A systematic review and meta-analysis of intervention studies among team sport players. J Sci Med Sport 2021; 24:931-938. [PMID: 33893033 DOI: 10.1016/j.jsams.2021.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 02/23/2021] [Accepted: 03/09/2021] [Indexed: 11/19/2022]
Abstract
OBJECTIVES The primary aim of this study was to investigate the effects of the Nordic hamstring exercise (NHE) on sprint performance (i.e., 5, 10 and 20m) and explore associations between study characteristics and sprint outcomes in team sport players. Secondary aims were to (1) investigate the effects of the NHE on eccentric strength of the knee flexors (ESKF) with categorical subgroup analysis to determine differences between recreationally, well-trained individuals and young athletes, (2) determine the relation between ESKF and sprint performance in team sport players, and (3) explore the effect of study characteristics (i.e., weekly volume, time duration and body mass) on ESKF. METHODS Electronic databases were searched until the 20th of June 2020. 17 studies met the inclusion criteria. Random-effects meta-analyses were used to determine the mean difference (MD) or standardized change of mean difference (SCMD) between NHE and control group for sprint time and ESKF, respectively. RESULTS NHE interventions showed a positive effect on sprint performance (-0.04s [-0.08, -0.01]). Sub-group meta-analyses indicated no significant differences in 5 and 20m sprint performance (MDsprint(5m)=-0.02s [-0.10, 0.06]) and (MD sprint(20m)=-0.05s [-0.30, 0.19]), respectively. A significant difference was however found for 10m sprint performance (MDsprint(10m)=-0.06s [-0.10, -0.01]). Meta-analysis on the effects of the NHE on ESKF showed a significant benefit of 0.83 SCMD [0.55, 1.12] in favour of the intervention group. CONCLUSIONS Studies with some concerns or high risk of bias show that training programs involving the NHE can have small beneficial effects on sprint performance in team sport players. Studies with some concerns or high risk of bias showed moderate beneficial effects on ESKF among a sample of relatively untrained individuals. However, for well-trained team sport players, the improvements in ESKF were less consistent, suggesting a higher training intensity during the NHE may be required to induce adaptations.
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Affiliation(s)
- Iker J Bautista
- Department of Physiotherapy, Catholic University of Valencia, Spain.
| | | | | | - Víctor Segarra
- ProElite Performance, CESADE Physiotherapist Clinic, Spain
| | - Fernando Martín
- Department of Physical Education and Sports, University of Valencia, Spain
| | - Bas Van Hooren
- Department of Nutrition and Movement Sciences, UNTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, The Netherlands
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70
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Schulze E, Julian R, Skorski S. The Accuracy of a Low-Cost GPS System during Football-Specific Movements. JOURNAL OF SPORTS SCIENCE AND MEDICINE 2021; 20:126-132. [PMID: 33707995 DOI: 10.52082/jssm.2021.126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 01/04/2021] [Indexed: 11/24/2022]
Abstract
An affordable player monitoring solution could make the evaluation of external loading more accessible across multiple levels of football (soccer). The present study aimed to determine the accuracy of a newly designed and low-cost Global Positioning System (GPS) whilst performing match-specific movement patterns. Sixteen professional male football players (24 ± 3 years) were assigned a GPS device (TT01, Tracktics GmbH, Hofheim, Germany) and completed two experimental trials. In each trial, a continuous protocol including seven movements (sideways cornering, diagonal cornering, accelerating, decelerating, backwards jogging, shuttle running, and skipping) adding up to 500 m, was completed. Time-motion data was compared with criterion distance and velocity (photo-cell timing gates and radar). Validity was assessed through the standard error of the estimate (SEE) and reliability through the coefficient of variation (CV; both with 95% confidence limits). For the total distance covered during the protocol, the system was found to be valid (SEE = 3.1% [2.2; 5.8]) and reliable (intra-device CV = 2.0% [1.2; 7.6]). Similar results were found for velocity (SEE = 3.4% [2.6; 4.8], CV = 4.7% [3.2; 8.5]). In conclusion, the present GPS system, a low-cost solution, was found to be a valid and reliable tool for measuring physical loading during football-specific movements.
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Affiliation(s)
- Emiel Schulze
- Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany
| | - Ross Julian
- Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany.,Institute of Neuromotor Behavior and Exercise, University of Münster, Münster, Germany.,School of Sport and Exercise, Exercise and Sport Research Centre, University of Gloucestershire, England
| | - Sabrina Skorski
- Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany
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Yu Z, Liu Y, Zhu C. Comparative Anesthesia Effect of Brachial Plexus Block Based on Smart Electronic Medical Ultrasound-Guided Positioning and Traditional Anatomical Positioning. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:6676610. [PMID: 33728033 PMCID: PMC7935580 DOI: 10.1155/2021/6676610] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/21/2021] [Accepted: 02/15/2021] [Indexed: 12/25/2022]
Abstract
With the intensification of population aging, the improvement of visualization technology, and the concept of accelerated rehabilitation surgery, the anesthesia method of upper extremity surgery is gradually changing. However, these methods are often caused by anatomical variations and often have low block success rates and patient satisfaction. The neuroanatomical position should be accurately located so that the puncture needle is right next to the nerve bundle or in the nerve sheath. This is very important for implementing accurate brachial plexus anesthesia. This article uses ultrasound-guided positioning technology and traditional anatomical positioning technology for brachial plexus block treatment, aiming to explore the anesthesia effect of brachial plexus block with different techniques. This article selects 120 patients undergoing brachial plexus block surgery for forearm or hand surgery and divides these 120 patients into 6 groups with 20 people in each group. The first 3 groups were treated with brachial plexus block using ultrasound-guided positioning technology. The latter 3 groups were treated with brachial plexus block using traditional anatomical positioning technology. Experiments proved that during anesthesia, compared with the ultrasound group, the heart rate of the traditional anatomy group was significantly decreased (P < 0.05), and the average arterial pressure of the six groups of patients at each time point had no statistical difference (P > 0.05). This shows that whether it is ultrasound-guided positioning technology or traditional anatomical positioning technology, it has no effect on the average arterial pressure of the patient at each time point. In addition to intuitive and accurate viewing of needle and nerve contact, ultrasound real-time guidance allows intuitive viewing of anesthesia. This is a special advantage of nerve block under ultrasound guidance.
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Affiliation(s)
- Zhaoxiang Yu
- Department of Anesthesiology, Affiliated Hospital of Beihua University, Jilin 132012, Jilin, China
| | - Yang Liu
- Department of Endocrine, Affiliated Hospital of Beihua University, Jilin 132012, Jilin, China
| | - Chunlei Zhu
- Department of Hand and Foot Surgery, Affiliated Hospital of Beihua University, Jilin 132012, Jilin, China
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72
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Dasa MS, Kristoffersen M, Ersvær E, Bovim LP, Bjørkhaug L, Moe-Nilssen R, Sagen JV, Haukenes I. The Female Menstrual Cycles Effect on Strength and Power Parameters in High-Level Female Team Athletes. Front Physiol 2021; 12:600668. [PMID: 33692699 PMCID: PMC7937612 DOI: 10.3389/fphys.2021.600668] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 01/29/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose The female menstrual cycle (MC) is characterized by hormonal fluctuations throughout its different phases. However, research regarding its effect on athletic performance in high level athletes is sparse. The aim of this study was to (i) investigate the female MCs effect on strength and power performance in highly trained female team athletes throughout the MC and (ii) examine whether eumenorrheic participants with natural hormonal fluctuations displayed enhanced performance in the follicular phase (FP) versus the luteal phase (LP), compared to controls using hormonal contraceptives. Materials and Methods A total of 29 athletes (Age 21.2 ± 3.3 years; weight 65.6 ± 8.7 kg; height 170.2 ± 8.0 cm; and fat free mass 52.7 ± 7.1) completed the study after a 6-week testing period (8 eumenorrheic participants and 21 hormonal contraceptive controls). Participants were recruited from the team sports soccer, handball and volleyball. Testing protocol consisted of maximal voluntary isometric grip strength, 20-m sprint, countermovement jump and pneumatic leg-press. Based on self-reported use of hormonal contraceptives, participants were divided into non-hormonal contraceptive group and hormonal contraceptive group, the latter working as a control group. Differences in performance between the FP and LP were investigated. MC phase was confirmed by serum hormonal levels through venous blood samples in the non-hormonal contraceptive group. Results There were no statistically significant changes for the two different phases of the MC, in terms of physical performance for the whole group. Further, there was no significant difference between groups during the MC for any of the outcome variables, maximal voluntary isometric grip strength F(3.29) = 0.362; 20-m sprint F(3.24) = 0.710; countermovement jump F(3.26) = 2.361; and leg-press F(3.26) = 1.746. Conclusion In high level female team athletes, no difference in performance was observed based on hormonal contraceptive status. This suggests that the MC does not alter acute strength and power performance on a group level in high level team athletes.
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Affiliation(s)
- Marcus S Dasa
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Morten Kristoffersen
- Department of Sport, Food, and Natural Sciences, Western Norway University of Applied Sciences, Bergen, Norway
| | - Elisabeth Ersvær
- Department of Safety, Chemistry, and Biomedical Laboratory Sciences, Western Norway University of Applied Sciences, Bergen, Norway
| | - Lars Peder Bovim
- Department of Health and Functioning, Western Norway University of Applied Sciences, Bergen, Norway
| | - Lise Bjørkhaug
- Department of Safety, Chemistry, and Biomedical Laboratory Sciences, Western Norway University of Applied Sciences, Bergen, Norway
| | - Rolf Moe-Nilssen
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Jørn V Sagen
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Inger Haukenes
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Research Unit for General Practice, NORCE Norwegian Research Centre, Bergen, Norway
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Windt J, MacDonald K, Taylor D, Zumbo BD, Sporer BC, Martin DT. "To Tech or Not to Tech?" A Critical Decision-Making Framework for Implementing Technology in Sport. J Athl Train 2021; 55:902-910. [PMID: 32991702 DOI: 10.4085/1062-6050-0540.19] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The current technological age has created exponential growth in the availability of technology and data in every industry, including sport. It is tempting to get caught up in the excitement of purchasing and implementing technology, but technology has a potential dark side that warrants consideration. Before investing in technology, it is imperative to consider the potential roadblocks, including its limitations and the contextual challenges that compromise implementation in a specific environment. A thoughtful approach is therefore necessary when deciding whether to implement any given technology into practice. In this article, we review the vision and pitfalls behind technology's potential in sport science and medicine applications and then present a critical decision-making framework of 4 simple questions to help practitioners decide whether to purchase and implement a given technology.
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Affiliation(s)
- Johann Windt
- Vancouver Whitecaps FC, BC, Canada.,University of British Columbia, Vancouver, Canada
| | | | - David Taylor
- United States Olympic and Paralympic Committee, Colorado Springs, CO
| | | | - Ben C Sporer
- Vancouver Whitecaps FC, BC, Canada.,University of British Columbia, Vancouver, Canada
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Video-Based System for Automatic Measurement of Barbell Velocity in Back Squat. SENSORS 2021; 21:s21030925. [PMID: 33573170 PMCID: PMC7866505 DOI: 10.3390/s21030925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 11/17/2022]
Abstract
Velocity-based training is a contemporary method used by sports coaches to prescribe the optimal loading based on the velocity of movement of a load lifted. The most employed and accurate instruments to monitor velocity are linear position transducers. Alternatively, smartphone apps compute mean velocity after each execution by manual on-screen digitizing, introducing human error. In this paper, a video-based instrument delivering unattended, real-time measures of barbell velocity with a smartphone high-speed camera has been developed. A custom image-processing algorithm allows for the detection of reference points of a multipower machine to autocalibrate and automatically track barbell markers to give real-time kinematic-derived parameters. Validity and reliability were studied by comparing the simultaneous measurement of 160 repetitions of back squat lifts executed by 20 athletes with the proposed instrument and a validated linear position transducer, used as a criterion. The video system produced practically identical range, velocity, force, and power outcomes to the criterion with low and proportional systematic bias and random errors. Our results suggest that the developed video system is a valid, reliable, and trustworthy instrument for measuring velocity and derived variables accurately with practical implications for use by coaches and practitioners.
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Kennedy RA, Drake D. Improving the Signal-To-Noise Ratio When Monitoring Countermovement Jump Performance. J Strength Cond Res 2021; 35:85-90. [PMID: 29742747 DOI: 10.1519/jsc.0000000000002615] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Kennedy, RA and Drake, D. Improving the signal-to-noise ratio when monitoring countermovement jump performance. J Strength Cond Res 35(1): 85-90, 2021-Countermovement jump (CMJ) performance has been routinely used to monitor neuromuscular status. However, the protocol used to establish the criterion score is not well documented. The purpose of this study was to examine how the protocol used would influence of the sensitivity of CMJ variables in rugby union players. Fifteen male (age: 19.7 ± 0.5 years) rugby union players performed 8 CMJs on 2 occasions, separated by 7 days. The between-session coefficient of variation (CV) was calculated using 2 techniques for treating multiple trials, the average, and the trial with the best jump height (JH), and then compared with the smallest worthwhile change (SWC). The signal-to-noise ratio was measured as the group mean change in a variable divided by the CV. Using the average value across multiple trials is superior to the best trial method, based on lower CVs for all variables. Only the average performance across 6 or more trials was classified as ideal (CV < 0.5 × SWC) for peak velocity (PV). In addition, the signal-to-noise ratio for peak concentric power (PCP), PV, and JH were classified as good, irrespective of the treatment method. Although increasing the number of trials can reduce the random error, it may be pragmatic to simply take the average from 2 to 3 trials, facilitating a CV < SWC for PV, PCP, and JH. Due to its simplicity, JH may be considered the principal variable to monitor neuromuscular fatigue.
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Affiliation(s)
- Rodney A Kennedy
- School of Sport, Ulster University, Jordanstown, Northern Ireland ; and
| | - David Drake
- Ulster Rugby, Kingspan Stadium, Belfast, Northern Ireland
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Savoia C, Padulo J, Colli R, Marra E, McRobert A, Chester N, Azzone V, Pullinger SA, Doran DA. The Validity of an Updated Metabolic Power Algorithm Based upon di Prampero's Theoretical Model in Elite Soccer Players. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17249554. [PMID: 33419381 PMCID: PMC7766422 DOI: 10.3390/ijerph17249554] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 01/29/2023]
Abstract
The aim of this study was to update the metabolic power (MP) algorithm (PV˙O2, W·kg−1) related to the kinematics data (PGPS, W·kg−1) in a soccer-specific performance model. For this aim, seventeen professional (Serie A) male soccer players (V˙O2max 55.7 ± 3.4 mL·min−1·kg−1) performed a 6 min run at 10.29 km·h−1 to determine linear-running energy cost (Cr). On a separate day, thirteen also performed an 8 min soccer-specific intermittent exercise protocol. For both procedures, a portable Cosmed K4b2 gas-analyzer and GPS (10 Hz) was used to assess the energy cost above resting (C). From this aim, the MP was estimated through a newly derived C equation (PGPSn) and compared with both the commonly used (PGPSo) equation and direct measurement (PV˙O2). Both PGPSn and PGPSo correlated with PV˙O2 (r = 0.66, p < 0.05). Estimates of fixed bias were negligible (PGPSn = −0.80 W·kg−1 and PGPSo = −1.59 W·kg−1), and the bounds of the 95% CIs show that they were not statistically significant from 0. Proportional bias estimates were negligible (absolute differences from one being 0.03 W·kg−1 for PGPSn and 0.01 W·kg−1 for PGPSo) and not statistically significant as both 95% CIs span 1. All variables were distributed around the line of unity and resulted in an under- or overestimation of PGPSn, while PGPSo routinely underestimated MP across ranges. Repeated-measures ANOVA showed differences over MP conditions (F1,38 = 16.929 and p < 0.001). Following Bonferroni post hoc test significant differences regarding the MP between PGPSo and PV˙O2/PGPSn (p < 0.001) were established, while no differences were found between PV˙O2 and PGPSn (p = 0.853). The new approach showed it can help the coaches and the soccer trainers to better monitor external training load during the training seasons.
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Affiliation(s)
- Cristian Savoia
- Research Institute for Sport and Exercise Sciences (RISES), Tom Reilly Building, Liverpool John Moores University, Liverpool L2 2ER, UK; (C.S.); (A.M.); (N.C.); (S.A.P.); (D.A.D.)
| | - Johnny Padulo
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, 20122 Milan, Italy
- Correspondence:
| | - Roberto Colli
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy;
| | - Emanuele Marra
- School of Sport Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, 00133 Rome, Italy;
| | - Allistair McRobert
- Research Institute for Sport and Exercise Sciences (RISES), Tom Reilly Building, Liverpool John Moores University, Liverpool L2 2ER, UK; (C.S.); (A.M.); (N.C.); (S.A.P.); (D.A.D.)
| | - Neil Chester
- Research Institute for Sport and Exercise Sciences (RISES), Tom Reilly Building, Liverpool John Moores University, Liverpool L2 2ER, UK; (C.S.); (A.M.); (N.C.); (S.A.P.); (D.A.D.)
| | - Vito Azzone
- Federazione Italiana Giuoco Calcio (F.I.G.C.), 00198 Rome, Italy;
| | - Samuel A. Pullinger
- Research Institute for Sport and Exercise Sciences (RISES), Tom Reilly Building, Liverpool John Moores University, Liverpool L2 2ER, UK; (C.S.); (A.M.); (N.C.); (S.A.P.); (D.A.D.)
| | - Dominic A. Doran
- Research Institute for Sport and Exercise Sciences (RISES), Tom Reilly Building, Liverpool John Moores University, Liverpool L2 2ER, UK; (C.S.); (A.M.); (N.C.); (S.A.P.); (D.A.D.)
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Nicholson B, Dinsdale A, Jones B, Till K. The Training of Short Distance Sprint Performance in Football Code Athletes: A Systematic Review and Meta-Analysis. Sports Med 2020; 51:1179-1207. [PMID: 33245512 PMCID: PMC8124057 DOI: 10.1007/s40279-020-01372-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background Short-sprint (≤ 20 m) performance is an important quality for success in the football codes. Therefore, developing an evidence base for understanding training methods to enhance short-sprint performance is key for practitioners. However, current systematic reviews are limited by (1) a lack of focus on football code athletes, (2) a lack of consideration of all training modalities and (3) a failure to account for the normal training practices undertaken by intervention groups within their analysis. Therefore, this review aimed to (1) conduct a systematic review of the scientific literature evaluating training interventions upon short-sprint performance within football code athletes, (2) undertake a meta-analysis to assess the magnitude of change of sport-sprint performance following training interventions and (3) identify how moderator variables affect the training response. Methods A systematic search of electronic databases was conducted. A random-effects meta-analysis was performed to establish standardised mean difference with 95% confidence intervals. This identified the magnitude and direction of the individual training effects of intervention subgroups (primary, secondary, combined-specific, tertiary and combined training methods) on short-sprint performance while considering moderator variables (i.e., football code, sex, age, playing standard, phase of season). Results 121 studies met the inclusion criteria, totalling 3419 athletes. Significant improvements (small-large) were found between pre- and post-training in short-sprint performance for the combined, secondary, tertiary and combined-specific training methods. No significant effect was found for primary or sport only training. No individual mode was found to be the most effective. Between-subgroup analysis identified that football code, age, playing standard and phase of season all moderated the overall magnitude of training effects. Conclusions This review provides the largest systematic review and meta-analysis of short-sprint performance development methods and the only one to assess football code athletes exclusively. Practitioners can apply combined, secondary and tertiary training methods to improve short-sprint performance within football code athletes. The application of sport only and primary methods does not appear to improve short-sprint performance. Regardless of the population characteristics, short-sprint performance can be enhanced by increasing either or both the magnitude and the orientation of force an athlete can generate in the sprinting action. Trial Registration OSF registration https://osf.io/kshqn/. Electronic supplementary material The online version of this article (10.1007/s40279-020-01372-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ben Nicholson
- Carnegie Applied Rugby Research (CARR) Centre, Carnegie School of Sport, Leeds Beckett University, Room G08, Cavendish Hall, Headingley Campus, Leeds, LS6 3QS, UK.
- Yorkshire Carnegie Rugby Union Club, Leeds, UK.
- Leeds Rhinos Rugby League Club, Leeds, UK.
| | - Alex Dinsdale
- Carnegie Applied Rugby Research (CARR) Centre, Carnegie School of Sport, Leeds Beckett University, Room G08, Cavendish Hall, Headingley Campus, Leeds, LS6 3QS, UK
| | - Ben Jones
- Carnegie Applied Rugby Research (CARR) Centre, Carnegie School of Sport, Leeds Beckett University, Room G08, Cavendish Hall, Headingley Campus, Leeds, LS6 3QS, UK
- Leeds Rhinos Rugby League Club, Leeds, UK
- England Performance Unit, The Rugby Football League, Leeds, UK
- School of Science and Technology, University of New England, Armidale, NSW, Australia
- Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, The University of Cape Town and the Sports Science Institute of South Africa, Cape Town, South Africa
| | - Kevin Till
- Carnegie Applied Rugby Research (CARR) Centre, Carnegie School of Sport, Leeds Beckett University, Room G08, Cavendish Hall, Headingley Campus, Leeds, LS6 3QS, UK
- Leeds Rhinos Rugby League Club, Leeds, UK
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Haugen TA, Breitschädel F, Samozino P. Power-Force-Velocity Profiling of Sprinting Athletes: Methodological and Practical Considerations When Using Timing Gates. J Strength Cond Res 2020; 34:1769-1773. [PMID: 30273283 DOI: 10.1519/jsc.0000000000002890] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Haugen, TA, Breitschädel, F, and Samozino, P. Power-force-velocity profiling of sprinting athletes: Methodological and practical considerations when using timing gates. J Strength Cond Res 34(6): 1769-1773, 2020-The aim of this study was to investigate the impact of timing gate setup on mechanical outputs in sprinting athletes. Twenty-five male and female team sport athletes (mean ± SD: 23 ± 4 years, 185 ± 11 cm, 85 ± 13 kg) performed two 40-m sprints with maximal effort. Dual-beamed timing gates covered the entire running course with 5-m intervals. Maximal horizontal force (F0), theoretical maximal velocity (v0), maximal horizontal power (Pmax), force-velocity slope (SFV), maximal ratio of force (RFmax), and index of force application technique (DRF) were computed using a validated biomechanical model and based on 12 varying split time combinations, ranging from 3 to 8 timing checkpoints. When no timing gates were located after the 20-m mark, F0 was overestimated (mean difference, ±90% confidence level: 0.16, ±0.25 to 0.33, ±0.28 N·kg; possibly to likely; small), in turn affecting SFV and DRF by small to moderate effects. Timing setups covering only the first 15 m displayed lower v0 than setups covering the first 30-40 m of the sprints (0.21, ±0.34 to 0.25, ±0.34 m·s; likely; small). Moreover, poorer reliability values were observed for timing setups covering the first 15-20 m vs. the first 25-40 m of the sprints. In conclusion, the present findings showed that the entire acceleration phase should be covered by timing gates to ensure acceptably valid and reliable sprint mechanical outputs. However, only 3 timing checkpoints (i.e., 10, 20, and 30 m) are required to ensure valid and reliable outputs for team sport athletes.
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Affiliation(s)
| | - Felix Breitschädel
- Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, Trondheim, Norway; and
| | - Pierre Samozino
- Inter-University Laboratory of Human Movement Biology, University Savoie Mont Blanc, Chambéry, France
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Effects of including endurance and speed sessions within small-sided soccer games periodization on physical fitness. Biol Sport 2020; 38:291-299. [PMID: 34079175 PMCID: PMC8139358 DOI: 10.5114/biolsport.2021.99325] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/26/2020] [Accepted: 08/31/2020] [Indexed: 11/17/2022] Open
Abstract
The main aim of this study was to analyse the effects of including additional speed and endurance sessions during small-sided games (SSG) training periodization on physical fitness in professional soccer players. Sixteen outfield players (age = 25.6 ± 7.6 years) who competed in the First Division of a European League participated in this study. Players were randomly assigned to perform only the SSG periodization (G-SSG group) or to add endurance and speed training contents to the SSG (ES-SSG group). Before and after the 6-week experimental period, a Yo-Yo Intermittent Recovery Test level 1 (YYIR1) and a 40 m sprinting test were performed. Rating of perceived exertion (RPE) was also measured after each training session. The G-SSG group showed a large improvement in the YYIR1 performance (p = 0.018–0.028; ES = 0.521–0.576) after the training programme, whereas no significant changes were observed for the ES-SSG group (p = 0.763–1.000; ES = 0.000–0.014). In addition, no significant differences (p > 0.05, ES = 0.005–361, trivial to small) in sprint performance at 5 and 10 m intervals up to 40 m were observed at post-training in comparison to pre-training evaluation in G-SSG and ES-SSG groups. No significant differences (p > 0.05) between groups were observed at baseline in the YYIR1 test. The 6-week SSG training supported with only six endurance and speed training sessions was no more effective than well-organized SSG alone for improving running endurance in professional soccer players.
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Alt PS, Baumgart C, Ueberschär O, Freiwald J, Hoppe MW. Validity of a Local Positioning System during Outdoor and Indoor Conditions for Team Sports. SENSORS 2020; 20:s20205733. [PMID: 33050174 PMCID: PMC7601858 DOI: 10.3390/s20205733] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/17/2020] [Accepted: 10/04/2020] [Indexed: 12/20/2022]
Abstract
This study aimed to compare the validity of a local positioning system (LPS) during outdoor and indoor conditions for team sports. The impact of different filtering techniques was also investigated. Five male team sport athletes (age: 27 ± 2 years; maximum oxygen uptake: 48.4 ± 5.1 mL/min/kg) performed 10 trials on a team sport-specific circuit on an artificial turf and in a sports hall. During the circuit, athletes wore two devices of a recent 20-Hz LPS. From the reported raw and differently filtered velocity data, distances covered during different walking, jogging, and sprinting sections within the circuit were computed for which the circuit was equipped with double-light timing gates as criterion measures. The validity was determined by comparing the known and measured distances via the relative typical error of estimate (TEE). The LPS validity for measuring distances covered was good to moderate during both environments (TEE: 0.9–7.1%), whereby the outdoor validity (TEE: 0.9–6.4%) was superior than indoor validity (TEE: 1.2–7.1%). During both environments, validity outcomes of an unknown manufacturer filter were superior (TEE: 0.9–6.2%) compared to those of a standard Butterworth filter (TEE: 0.9–6.4%) and to unprocessed raw data (TEE: 1.0–7.1%). Our findings show that the evaluated LPS can be considered as a good to moderately valid tracking technology to assess running-based movement patterns in team sports during outdoor and indoor conditions. However, outdoor was superior to indoor validity, and also impacted by the applied filtering technique. Our outcomes should be considered for practical purposes like match and training analyses in team sport environments.
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Affiliation(s)
- Prisca S. Alt
- Department of Orthopaedic and Traumatic Surgery, Clinic Braunschweig, 38118 Braunschweig, Germany
- Correspondence: ; Tel.: +49-176-2388-8451
| | - Christian Baumgart
- Department of Movement and Training Science, University of Wuppertal, 42119 Wuppertal, Germany; (C.B.); (J.F.)
| | - Olaf Ueberschär
- Department of Engineering and Industrial Design, Magdeburg-Stendal University of Applied Sciences, 39114 Magdeburg, Germany;
- Department of Biomechanics, Institute for Applied Training Science, 04109 Leipzig, Germany
| | - Jürgen Freiwald
- Department of Movement and Training Science, University of Wuppertal, 42119 Wuppertal, Germany; (C.B.); (J.F.)
| | - Matthias W. Hoppe
- Institute of Movement and Training Science I, University of Leipzig, 04109 Leipzig, Germany;
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Integrated Strength and Fundamental Movement Skill Training in Children: A Pilot Study. CHILDREN-BASEL 2020; 7:children7100161. [PMID: 33022968 PMCID: PMC7601651 DOI: 10.3390/children7100161] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/16/2020] [Accepted: 09/30/2020] [Indexed: 11/24/2022]
Abstract
Competence in fundamental movement skills is essential to enable children to be physically active. We investigated the effect of an integrated fundamental movement skill with a strength training intervention on children’s fundamental movement skills. Seventy-two (53% female) 10- to 11-year-old children from three primary schools assented to take part in this study (87% compliance). Schools were randomly allocated to a control (no intervention; n = 21), fundamental movement skill (FMS) (n = 18) or FMS and strength (FMS+; n = 20) group. Interventions were delivered twice weekly for four weeks, in addition to normal physical education. FMS competence was measured through the Canadian agility and movement skills assessment (CAMSA) (product-process) and through countermovement jump (CMJ) and 40-m sprint tests (product). Improvements were observed in the CAMSA in both FMS (4.6, 95% confidence intervals 2.9 to 6.4 Arbitrary Units (AUs), second-generation p-value (pδ) = 0.03) and FMS+ (3.9, 2.1 to 5.3 AU, pδ = 0.28) with no difference beyond our minimum threshold of 3 AU observed between these intervention groups (pδ = 1). Clear improvements in CMJ were observed in FMS+ relative to the control (25, 18 to 32%, pδ = 0) and FMS groups (15, 6.1 to 24%, pδ = 0). These preliminary data suggest combined FMS and strength training warrants further investigation as a tool to develop fundamental movement skills in children.
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Altarriba-Bartes A, Peña J, Vicens-Bordas J, Milà-Villaroel R, Calleja-González J. Post-competition recovery strategies in elite male soccer players. Effects on performance: A systematic review and meta-analysis. PLoS One 2020; 15:e0240135. [PMID: 33007044 PMCID: PMC7531804 DOI: 10.1371/journal.pone.0240135] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 09/19/2020] [Indexed: 11/30/2022] Open
Abstract
Aims The main aim of the present review was to update the available evidence on the value interest of post-competition recovery strategies in male professional or semi-professional soccer players to determine its effect on post-game performance outcomes, physiological markers, and wellness indicators. Methods A structured search was carried out following the PRISMA guidelines using six online databases: Pubmed, Scopus, SPORTDiscus, Web of Science, CINAHL and Cochrane Central Register of Controlled Trials. The risk of bias was completed following the Cochrane Collaboration Guidelines. Meta-analyses of randomized controlled trials were conducted to determine the between and within-group effects of different recovery strategies on performance, physiological markers and wellness data. Final meta-analyses were performed using the random-effects model and pooled standardized mean differences (SMD). Results Five randomized controlled trials that used Compression Garments (n = 3), Cold Water Immersion (n = 1), and acute Sleep Hygiene Strategy (n = 1) were included. Greater CMJ values at 48h for the intervention group (SMD = 0.70; 95% CI 0.14 to 1.25; p = 0.001; I2 = 10.4%) were found. For the 20-m sprint and MVC, the results showed no difference either at 24h or 48h. For physiological markers (CK and CRP) and wellness data (DOMS), small to large SMD were present in favor of the intervention group both at 24h (-0.12 to -1.86) and 48h (-0.21 to -0.85). No heterogeneity was present, except for MVC at 24h (I2 = 90.4%; p = 0.0012) and CALF DOMS at 48h (I2 = 93.7%; p = 0.013). Conclusion The use of recovery strategies offers significant positive effects only in jumping performance (CMJ), with no effects on the 20-m sprint or MVC. Also, the use of recovery strategies offers greater positive effects on muscle damage (physiological markers and wellness data), highlighting the importance of post-match recovery strategies in soccer.
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Affiliation(s)
- Albert Altarriba-Bartes
- Sport Performance Analysis Research Group (SPARG), University of Vic-Central University of Catalonia, Vic, Barcelona, Spain
- UVic-UCC Sport and Physical Activity Studies Centre (CEEAF), University of Vic-Central University of Catalonia, Vic, Barcelona, Spain
| | - Javier Peña
- Sport Performance Analysis Research Group (SPARG), University of Vic-Central University of Catalonia, Vic, Barcelona, Spain
- UVic-UCC Sport and Physical Activity Studies Centre (CEEAF), University of Vic-Central University of Catalonia, Vic, Barcelona, Spain
- * E-mail:
| | - Jordi Vicens-Bordas
- UVic-UCC Sport and Physical Activity Studies Centre (CEEAF), University of Vic-Central University of Catalonia, Vic, Barcelona, Spain
- Department of Medical Sciences, Research Group of Clinical Anatomy, Embryology and Neuroscience (NEOMA), School of Health and Sport Sciences (EUSES), University of Girona, Girona, Spain
- School of Health and Sport Sciences (EUSES), Universitat de Girona, Salt, Spain
| | - Raimon Milà-Villaroel
- Global Research on Wellbeing (GRoW), Blanquerna School of Health Sciences-Ramon Llull University, Barcelona, Spain
| | - Julio Calleja-González
- Department of Physical Education and Sports, Faculty of Education and Sport, University of the Basque Country, UPV/EHU, Vitoria-Gasteiz, Spain
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83
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Sagelv EH, Pedersen S, Nilsen LPR, Casolo A, Welde B, Randers MB, Pettersen SA. Flywheel squats versus free weight high load squats for improving high velocity movements in football. A randomized controlled trial. BMC Sports Sci Med Rehabil 2020; 12:61. [PMID: 33024564 PMCID: PMC7532637 DOI: 10.1186/s13102-020-00210-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/24/2020] [Indexed: 02/07/2023]
Abstract
Background High load (HL: > 85% of one repetition maximum (1RM)) squats with maximal intended velocity contractions (MIVC) combined with football sessions can be considered a relevant and time-efficient practice for maintaining and improving high velocity movements in football. Flywheel (FW) resistance exercise (RE) have recently emerged with promising results on physical parameters associated with football performance. Methods In this randomized controlled trial over 6 weeks, 38 recreationally active male football players randomly performed RE with MIVCs two times per week as either 1) FW squats (n = 13) or 2) barbell free weight (BFW) HL squats (n = 13), where a third group served as controls (n = 12). All three groups conducted 2–3 football sessions and one friendly match a week during the intervention period. Pre- to post changes in 10-m sprint, countermovement jump (CMJ) and 1RM partial squat were assessed with univariate analyses of variance. Results The FW and BFW group equally improved their 10-m sprint time (2 and 2%, respectively, within group: both p < 0.001) and jump height (9 and 8%, respectively, within group: both p < 0.001), which was superior to the control group’s change (between groups: both p < 0.001). The BFW group experienced a larger increase (46%) in maximal squat strength than the FW group (17%, between groups: p < 0.001), which both were higher than the control group’s change (both p < 0.001). Conclusion Squats carried out with FWs or BFWs where both are performed with MIVCs and combined with football sessions, were equally effective in improving sprint time and jump height in football players. The BFW group experienced a more than two-fold larger increase in maximal partial squat strength than the FW group in maximal partial squat strength. This presents FW RE as an alternative to BFW HL RE for improving high velocity movements in football. Trial registration ClinicalTrials.gov Identifier: NCT04113031 (retrospectively registered, date: 02.10.2019).
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Affiliation(s)
- Edvard H Sagelv
- School of Sport Sciences, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway
| | - Sigurd Pedersen
- School of Sport Sciences, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway
| | - Lars Petter R Nilsen
- School of Sport Sciences, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway
| | - Andrea Casolo
- Department of Movement, Human and Health Sciences, University of Rome 'Foro Italico', Rome, Italy.,Department of Bioengineering, Imperial College London, London, UK
| | - Boye Welde
- School of Sport Sciences, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway
| | - Morten B Randers
- School of Sport Sciences, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway.,Department of Sport Sciences and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Svein Arne Pettersen
- School of Sport Sciences, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway
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Validity, reliability and usefulness of smartphone and kinovea motion analysis software for direct measurement of vertical jump height. Physiol Behav 2020; 227:113144. [PMID: 32822710 DOI: 10.1016/j.physbeh.2020.113144] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/07/2020] [Accepted: 08/09/2020] [Indexed: 11/21/2022]
Abstract
Jumping is a simple exercise determined by several biomechanical and physiological factors. Measures of vertical jump height are common and easy to administer tests of lower limb muscle power that are carried out with several types of equipment. This study aimed to validate and address the usefulness of the combination of smartphone and computer-based applications (Smartphone-Kinovea) against a laboratory-based Motion Capture System. One hundred and twelve healthy adults performed three maximal-effort countermovement jumps each. Both instruments measured the heights of the 336 trials concurrently while tracking the excursion of the body center of gravity. The vertical velocity at take-off vto and the impulse J were computed with jump height h measures. Intraclass correlation coefficient (ICC) results indicated very high agreement for h and vto (0.985) and almost perfect agreement for J (0.997), and Cronbach's α=0.99. Low mean differences were observed between instruments for h: -0.22 ± 1.15 cm, vto: -0.01 ± 0.04 m/s, and J: -0.56 ± 2.92 Ns, all p<0.01. The smallest worthwhile change (SWC) and the typical error of measurement (SEM) were 1.34 cm, 0.81 cm for h; 1.15 m/s, 0.03 m/s for vto, and 2.93 Ns, 2.25 Ns for J, so the usefulness of the method is established (SWC/SEM>1). Bland-Altman plots showed very low mean systematic bias ± random errors (-0.22 ± 2.25 cm; -0.01 ± 0.08 m/s; -0.56 ± 5.73 Ns), without association between their magnitudes (r2=0.005, r2=0.005, r2=0.001). Finally, very high to practically perfect correlation between isntruments were observed (r = 0.985; r = 0.986; r = 0.997). Our results suggest that the Smartphone-Kinovea method is a valid and reliable, low-cost instrument to monitor changes in jump performance in a healthy, active population diverse in gender and physical condition.
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85
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Apte S, Meyer F, Gremeaux V, Dadashi F, Aminian K. A Sensor Fusion Approach to the Estimation of Instantaneous Velocity Using Single Wearable Sensor During Sprint. Front Bioeng Biotechnol 2020; 8:838. [PMID: 33014992 PMCID: PMC7461787 DOI: 10.3389/fbioe.2020.00838] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 06/30/2020] [Indexed: 11/30/2022] Open
Abstract
Power-Force-Velocity profile obtained during a sprint test is crucial for designing personalized training and evaluating injury risks. Estimation of instantaneous velocity is requisite for developing these profiles and the predominant method for this estimation assumes it to have a first order exponential behavior. While this method remains appropriate for maximal sprints, the sprint velocity profile may not always show a first-order exponential behavior. Alternately, velocity profile has been estimated using inertial sensors, with a speed radar, or a smartphone application. Existing methods either relied on the exponential behavior or timing gates for drift removal, or estimated only the mean velocity. Thus, there is a need for a more flexible and appropriate approach, allowing for instantaneous velocity estimation during sprint tests. The proposed method aims to solve this problem using a sensor fusion approach, by combining the signals from wearable Global Navigation Satellite System (GNSS) and inertial measurement unit (IMU) sensors. We collected data from nine elite sprinters, equipped with a wearable GNSS-IMU sensor, who ran two trials each of 60 and 30/40 m sprints. We developed an algorithm using a gradient descent-based orientation filter, which simplified our model to a linear one-dimensional model, thus allowing us to use a simple Kalman filter (KF) for velocity estimation. We used two cascaded KFs, to segment the sprint data precisely, and to estimate the velocity and the sprint duration, respectively. We validated the estimated velocity and duration with speed radar and photocell data as reference. The median RMS error for the estimated velocity ranged from 6 to 8%, while that for the estimated sprint duration lied between 0.1 and -6.0%. The Bland-Altman plot showed close agreement between the estimated and the reference values of maximum velocity. Examination of fitting errors indicated a second order exponential behavior for the sprint velocity profile, unlike the first order behavior previously suggested in literature. The proposed sensor-fusion algorithm is valid to compute an accurate velocity profile with respect to the radar; it can compensate for and improve upon the accuracy of the individual IMU and GNSS velocities. This method thus enables the use of wearable sensors in the analysis of sprint test.
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Affiliation(s)
- Salil Apte
- Laboratory of Movement Analysis and Measurement, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Frederic Meyer
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Vincent Gremeaux
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
- Sport Medicine Unit, Division of Physical Medicine and Rehabilitation, Swiss Olympic Medical Center, Lausanne University Hospital, Lausanne, Switzerland
| | | | - Kamiar Aminian
- Laboratory of Movement Analysis and Measurement, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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86
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Rojas-Valverde D, Montoya-Rodríguez J, Azofeifa-Mora C, Sanchez-Urena B. Effectiveness of beetroot juice derived nitrates supplementation on fatigue resistance during repeated-sprints: a systematic review. Crit Rev Food Sci Nutr 2020; 61:3395-3406. [PMID: 32715742 DOI: 10.1080/10408398.2020.1798351] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In recent decades, the search for non-doping substances that enhance sports performance has increased. Ergogenic aids such as beetroot juice (BRJ) and BRJ rich in nitrates (NO3-) are widely used to cause physiological benefits that may lead to physical improvements. Therefore, the purpose of this systematic review was to explore the knowledge reported to date on the NO3- derived from BRJ intake effect on fatigue resistance during repeated sprints. A digital search was conducted following systematic review guidelines, and 18 studies met inclusion criteria from a total of 209 articles. In a third of the selected studies, the consumption of beet juice rich in NO3- contributes to an increase in nitrites in plasma that led to the rise in peak power, mean power, number of sprint repetitions, total work and time to task failure, and causes a decrease in fatigue index and sprints times. Some different dose has been proposed for both chronic and acute protocols. It seems that a chronic intake of ∼5-6 mmol of NO3- in 70 ml of BRJ, twice a day, for a minimum of 3-6 days could lead to a fatigue resistance improvement during repeated sprints. Besides, acute intake of NO3- 2.5-3 h before physical exertion or a dose of 250 ml/d to 500 ml/d of BRJ could lead to similar effective results. This systematic review presents some improvements (1.2-5.38%) in fatigue resistance during repeated sprints when consuming BRJ derived NO3-. The in-field practical meaning of these results should be explored.
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Affiliation(s)
- Daniel Rojas-Valverde
- Centro de Investigación y Diagnóstico en Salud y Deporte (CIDISAD), Escuela Ciencias del Movimiento Humano y Calidad de Vida (CIEMHCAVI), Universidad Nacional de Costa Rica, Heredia, Costa Rica.,Grupo de Avances en el Entrenamiento Deportivo y Acondicionamiento Físico (GAEDAF), Facultad Ciencias del Deporte), Universidad de Extremadura, Caceres, Spain
| | - Jaqueline Montoya-Rodríguez
- Centro de Investigación y Diagnóstico en Salud y Deporte (CIDISAD), Escuela Ciencias del Movimiento Humano y Calidad de Vida (CIEMHCAVI), National University of Costa Rica, Heredia, Costa Rica
| | - Christian Azofeifa-Mora
- Programa de Ciencias del Ejercicio y la Salud (PROCESA), Escuela Ciencias del Movimiento Humano y Calidad de Vida (CIEMHCAVI), National University of Costa Rica, Heredia, Costa Rica
| | - Braulio Sanchez-Urena
- Programa de Ciencias del Ejercicio y la Salud (PROCESA), Escuela Ciencias del Movimiento Humano y Calidad de Vida (CIEMHCAVI), National University of Costa Rica, Heredia, Costa Rica
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87
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Vicens-Bordas J, Esteve E, Fort-Vanmeerhaeghe A, Casals M, Bandholm T, Ishøi L, Opar D, Shield A, Thorborg K. Performance changes during the off-season period in football players - Effects of age and previous hamstring injury. J Sports Sci 2020; 38:2489-2499. [PMID: 32658565 DOI: 10.1080/02640414.2020.1792160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The aims of this study were to investigate changes in selected performance measures during an off-season period, their association, and the potential role of age and previous hamstring injury in semi-professional and amateur football players. Seventy-four male players (age: 25 ± 4 years, stature: 178.0 ± 6.6 cm, body mass: 74.9 ± 8.1 kg) were assessed at the beginning and end of the off-season summer-period for sprint, change-of-direction performance and eccentric hamstring strength. Small to medium increases in sprint times were observed at 5 (d = 0.26, p = 0.057), 10 (d = 0.42, p < 0.001) and 30 m (d = 0.64, p < 0.001). Small (d = -0.23, p = 0.033) improvements were observed for COD performance, and no changes in eccentric hamstring strength (d = 0.10, p = 0.317). The changes in the outcomes were not affected by age (p = 0.449 to 0.928) or previous hamstring injury (p = 0.109 to 0.995). The impaired sprint performance was not related to changes in eccentric hamstring strength (r = -0.21 to 0.03, p = 0.213 to 0.856), instead, changes in COD performance were associated with changes in eccentric hamstring strength (r = -0.42, p = 0.008).
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Affiliation(s)
- Jordi Vicens-Bordas
- Sportclínic. Physiotherapy and Sports Training Centre , Girona, Spain.,School of Health and Sport Sciences (EUSES), Universitat de Girona , Salt, Spain.,Research Group of Clinical Anatomy, Embryology and Neuroscience (NEOMA), Department of Medical Sciences, Universitat de Girona , Girona, Spain.,Sport and Physical Activity Studies Centre (CEEAF), University of Vic - Central University of Catalonia (UVic-UCC) , Spain
| | - Ernest Esteve
- Sportclínic. Physiotherapy and Sports Training Centre , Girona, Spain.,School of Health and Sport Sciences (EUSES), Universitat de Girona , Salt, Spain
| | | | - Martí Casals
- Sport and Physical Activity Studies Centre (CEEAF), University of Vic - Central University of Catalonia (UVic-UCC) , Spain.,Sport Performance Analysis Research Group, University of Vic , Barcelona, Spain.,Medical Department, Futbol Club Barcelona , Barcelona, Spain
| | - Thomas Bandholm
- Physical Medicine & Rehabilitation Research - Copenhagen (PMR-C), Department of Physical and Occupational Therapy, Department of Orthopedic Surgery, Clinical Research Center, Amager-Hvidovre Hospital, Copenhagen University , Hvidovre, Denmark
| | - Lasse Ishøi
- Sports Orthopedic Research Center - Copenhagen (SORC-C), Department of Orthopedic Surgery, Copenhagen University Hospital , Copenhagen, Denmark
| | - David Opar
- School of Behavioural and Health Sciences, Australian Catholic University , Melbourne, Australia
| | - Anthony Shield
- Faculty of Health, School of Exercise and Nutrition Science, Queensland University of Technology , Brisbane, Australia.,Institute of Health and Biomedical Innovation, Queensland University of Technology , Brisbane, Australia
| | - Kristian Thorborg
- Physical Medicine & Rehabilitation Research - Copenhagen (PMR-C), Department of Physical and Occupational Therapy, Department of Orthopedic Surgery, Clinical Research Center, Amager-Hvidovre Hospital, Copenhagen University , Hvidovre, Denmark.,Sports Orthopedic Research Center - Copenhagen (SORC-C), Department of Orthopedic Surgery, Copenhagen University Hospital , Copenhagen, Denmark
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Gepfert M, Golas A, Zajac T, Krzysztofik M. The Use of Different Modes of Post-Activation Potentiation (PAP) for Enhancing Speed of the Slide-Step in Basketball Players. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E5057. [PMID: 32674351 PMCID: PMC7400334 DOI: 10.3390/ijerph17145057] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/07/2020] [Accepted: 07/11/2020] [Indexed: 11/17/2022]
Abstract
Background: This study aimed to determine whether 5% of body mass-resisted or assisted conditioning activity (CA) can enhance 5 m slide-step movement performance. Methods: Sixteen division I basketball players participated in this study (23.6 ± 4.4 years; 86.3 ± 5.9 kg; 192.3 ± 6.2 cm; training experience 6.7 ± 2.6 years). The experiment was performed following a randomized crossover design, where each participant performed two different exercise protocols-assisted and resisted CA each consisting of four sets of 10 m slide-step movement with 5% of body mass external load and 1 min rest intervals between. To assess the differences between baseline and post-assisted, as well as post-resisted CA, the participants performed a 2 × 5 m slide-step movement 6 min after each CA protocol. The differences in time between baseline, post-assisted and post-resisted CA were examined using repeated-measures ANOVA. Results: ANOVA indicated a statistically significant difference between baseline and post-assisted postactivation performance enhancement (PAPE) (p = 0.011). There were no significant intragroup differences between baseline and post-resisted CA (p = 0.230). Conclusion: Findings of the study show that a light load assisted CA (5% of body mass) effectively elicits a potentiation response among basketball players.
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Affiliation(s)
- Mariola Gepfert
- Institute of Sport Sciences, The Jerzy Kukuczka Academy of Physical Education in Katowice, Mikolowska 72a, 40-065 Katowice, Poland; (M.G.); (A.G.)
| | - Artur Golas
- Institute of Sport Sciences, The Jerzy Kukuczka Academy of Physical Education in Katowice, Mikolowska 72a, 40-065 Katowice, Poland; (M.G.); (A.G.)
| | - Tomasz Zajac
- Human Performance Laboratory, The Jerzy Kukuczka Academy of Physical Education in Katowice, Mikolowska 72a, 40-065 Katowice, Poland;
| | - Michal Krzysztofik
- Institute of Sport Sciences, The Jerzy Kukuczka Academy of Physical Education in Katowice, Mikolowska 72a, 40-065 Katowice, Poland; (M.G.); (A.G.)
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89
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Bouguezzi R, Chaabene H, Negra Y, Ramirez-Campillo R, Jlalia Z, Mkaouer B, Hachana Y. Effects of Different Plyometric Training Frequencies on Measures of Athletic Performance in Prepuberal Male Soccer Players. J Strength Cond Res 2020; 34:1609-1617. [PMID: 32453304 DOI: 10.1519/jsc.0000000000002486] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Bouguezzi, R, Chaabene, H, Negra, Y, Ramirez-Campillo, R, Jlalia, Z, Mkaouer, B, and Hachana, Y. Effects of different plyometric training frequencies on measures of athletic performance in prepuberal male soccer players. J Strength Cond Res 34(6): 1609-1617, 2020-This study aimed to compare the effects of 1 vs. 2 sessions of equal-weekly volume plyometric training (PT) across 8 weeks on measures of athletic performance (i.e., sprint time, change of direction [CoD], jumping ability, and muscle strength) in prepuberal male soccer players. Thirty participants were randomly assigned either to 1 session PT group (1SPT [n = 15]) or 2 sessions PT group (2SPT [n = 15]). Plyometric training was integrated into their regular soccer training routine. Pretraining and posttraining tests for the assessment of sprint time (e.g., 5, 10, 20, and 30-m), CoD (e.g., T-test and modified Illinois change of direction test [MICODT]), jumping ability (e.g., standing long jump [SLJ], countermovement jump [CMJ], and squat jump [SJ]), muscle strength (reactive strength index [RSI]), and kicking distance were conducted. Results showed a main effect of time for 5-m sprint-time performance (F(1,56) = 4.00, effect size [ES] = 0.53 [medium], p = 0.05), T-test (F(1,56) = 23.19, ES = 1.28 [large], p < 0.001), MICODT (F(1,56) = 5.72, ES = 0.94 [large], p = 0.02), SLJ (F(1,56) = 16.63, ES = 1.09 [large], p < 0.001), CMJ (F(1,56) = 15.43, ES = 1.04 [large], p < 0.001), SJ (F(1,56) = 20.27, ES = 1.20 [large], p < 0.001), RSI (F(1,56) = 26.26, ES = 1.36 [large], p < 0.001), and kicking distance (F(1,56) = 47.19, ES = 1.83 [large], p < 0.001). There were no training group × time interactions in all the measured outcomes. In conclusion, when an equated moderate volume of jumps is performed, higher PT frequency across 8 weeks has no extra effects on prepuberal male soccer players' measures of athletic performance. The present findings may help optimizing PT interventions dedicated to prepuberal male soccer players.
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Affiliation(s)
- Raja Bouguezzi
- Research Unit (UR17JS01), "Sport Performance and Health," Higher Institute of Sport and Physical Education of Ksar Said, Tunis, Tunisia
| | - Helmi Chaabene
- Division of Training and Movement Sciences, Research Focus Cognition Sciences, University of Potsdam, Potsdam, Germany
- High Institute of Sports and Physical Education, Kef, University of Jendouba, Tunisia
| | - Yassine Negra
- Research Unit (UR17JS01), "Sport Performance and Health," Higher Institute of Sport and Physical Education of Ksar Said, Tunis, Tunisia
| | - Rodrigo Ramirez-Campillo
- Department of Physical Activity Sciences, Research Nucleus in Health, Physical Activity and Sport, University of Los Lagos, Osorno, Chile
| | - Zied Jlalia
- Faculty of Medicine of Tunis, University of Tunis El Manar, Orthopedic Pediatric Department, Kassab Institute of Orthopedic Surgery, Ksar Said, Tunisia
| | - Bessem Mkaouer
- Higher Institute of Sports and Physical Education of Ksar Said, Tunis, Tunisia
| | - Younés Hachana
- Research Unit (UR17JS01), "Sport Performance and Health," Higher Institute of Sport and Physical Education of Ksar Said, Tunis, Tunisia
- Higher Institute of Sports and Physical Education of Ksar Said, Tunis, Tunisia
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90
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Reliability and validity of the Chronojump open-source jump mat system. Biol Sport 2020; 37:255-259. [PMID: 32879547 PMCID: PMC7433325 DOI: 10.5114/biolsport.2020.95636] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/30/2020] [Accepted: 05/08/2020] [Indexed: 11/17/2022] Open
Abstract
Vertical jump performance is a commonly used test to measure lower-limb muscle power that is carried out with several types of equipment. The aim of this study was to validate an open-source jump mat (Chronojump Boscosystems) against a proprietary jump mat (Globus Ergo Tester). Sixty-three active sportsmen (age 23.3 ± 2.4 years) completed 8 maximal-effort countermovement jumps (CMJ). The heights of the 504 CMJ were measured from the two jump mats simultaneously. Reliability was examined with intra-class correlation coefficients (ICC), paired samples t-tests, coefficient of variation (CV) and Cronbach’s α. Bivariate Pearson’s correlation coefficient (r) was used to examine validity. Effects were evaluated using non-clinical magnitude-based inference. There was almost perfect agreement between instruments (ICC = 0.999−1.000, most likely positive 100/0/0). Paired t-test showed a mean difference of 0.03 ± 0.21 cm (90% CI -0.04 − -0.01) between instruments (most likely trivial 0/100/0). Both instruments showed very good stability (α = 1.00, CV = 4.28±1.95%). The smallest worthwhile change and typical error values were 1.3 and 0.29 cm, respectively and therefore, the signal-to-noise ratio of both instruments was large: 4.5. Finally, almost perfect correlation between instruments was observed (r = 0.999, most likely positive 100/0/0). Chronojump can be regarded as a sensitive instrument to detect changes in jump height performance over the possible noise around the measure. The results supported the open-source jump mat to be a useful, valid and reliable, low-cost testing device to monitor variations in vertical jumping performance.
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91
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Perez J, Guilhem G, Hager R, Brocherie F. Mechanical determinants of forward skating sprint inferred from off- and on-ice force-velocity evaluations in elite female ice hockey players. Eur J Sport Sci 2020; 21:192-203. [PMID: 32241241 DOI: 10.1080/17461391.2020.1751304] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This study aimed to investigate the correlations between players' mechanical capacities determined during off- and on-ice tests. Whole body force-velocity relationships were assessed in elite female ice hockey players (n = 17) during jumping [squat jump (SJ)], running (5 and 30 m) and skating (5 and 40 m) sprint tasks. Mechanical capacities estimates include relative maximal theoretical force (F0rel), velocity (V0), power (Pmaxrel), slope of the linear relationship between force relative to body mass and velocity (SFVrel), maximal horizontal component of the ground reaction force to the corresponding resultant force (RFmax) and minimal rate of decrease of this ratio (DRF). On-ice mechanical capacities (F0rel, Pmaxrel, RFmax and DRF) largely-to-very largely correlated with 40-m skating split time (r ranging from 0.82 for DRF to -0.91 for Pmaxrel; p < 0.001). Performance variables (SJ height, 30-m running and 40-m forward skating split time) and Pmaxrel demonstrated the largest associations between jumping, running and skating tasks (r ranging from -0.81 for 30-m sprint running time to 0.92 for SJ height; p < 0.001). Small (V0, SFVrel, DRF and force-velocity deficit) to very large (Pmaxrel) correlations (r ranging from 0.58 to 0.72; p < 0.05) were obtained between mechanical variables inferred from off- and on-ice force-velocity tests. The capacity to generate high amounts of horizontal power and effective horizontal force during the first steps on the ice is paramount for forward skating sprint performance. Mechanical capacities determined during forward skating sprint could be considered in ice hockey testing to identify fitness and/or technical/training requirements.
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Affiliation(s)
- Jérôme Perez
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport (INSEP), Paris, France.,French Ice Hockey Federation, Cergy, France
| | - Gaël Guilhem
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport (INSEP), Paris, France
| | - Robin Hager
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport (INSEP), Paris, France
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport (INSEP), Paris, France
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92
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Reliability of Change of Direction and Agility Assessments in Youth Soccer Players. Sports (Basel) 2020; 8:sports8040051. [PMID: 32325738 PMCID: PMC7240391 DOI: 10.3390/sports8040051] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 12/02/2022] Open
Abstract
Considering the vast physical and neural developments experienced throughout adolescence, the reliability of physical performance may vary in youth populations. This study aimed to examine the reliability of change of direction (COD) and agility tests in youth soccer players. Altogether, 86 youth soccer players, aged 13.6 ± 2.0 years, volunteered to participate. Data were collected from a modified 505 COD test (m505COD) and the Y-sprint drill in both pre-planned (Y-SprintPRE) and reactive (Y-SprintREACT) conditions during 2 sessions, 7 days apart. Anthropometric data including body mass, standing stature, and sitting height were also collected. COD and agility tests demonstrated good reliability (ICC = 0.81–0.91; CV = 1.2–2.0; d = 0.00–0.31; p < 0.01) for our entire sample. However, we observed a small negative relationship between age and intersession differences for the Y-SprintPRE (r = −0.28; p = 0.04), and moderate negative relationships between both age (r = −0.41; p < 0.01), and maturity offset (r = −0.39; p < 0.01) for the Y-SprintREACT. Although the COD and agility tests adopted within this study possess good intersession reliability, we observed greater intersession differences for younger and less mature individuals. We suggest that while COD and agility tests may provide meaningful objective data for monitoring the development of youth soccer players, these tests should be used with caution when evaluating younger, more immature athletes.
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93
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Hurst P, Schipof-Godart L, Hettinga F, Roelands B, Beedie C. Improved 1000-m Running Performance and Pacing Strategy With Caffeine and Placebo: A Balanced Placebo Design Study. Int J Sports Physiol Perform 2020; 15:483-488. [PMID: 31575826 DOI: 10.1123/ijspp.2019-0230] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/18/2019] [Accepted: 07/08/2019] [Indexed: 11/18/2022]
Abstract
PURPOSE To investigate the placebo effect of caffeine on pacing strategy and performance over 1000-m running time trials using a balanced placebo design. METHODS Eleven well-trained male middle-distance athletes performed seven 1000-m time trials (1 familiarization, 2 baseline, and 4 experimental). Experimental trials consisted of the administration of 4 randomized treatments: informed caffeine/received caffeine, informed caffeine/received placebo, informed placebo/received caffeine, and informed placebo/received placebo. Split times were recorded at 200, 400, 600, 800, and 1000 m, and peak heart rate and rating of perceived exertion were recorded at the completion of the trial. RESULTS Relative to baseline, participants ran faster during informed caffeine/received caffeine (d = 0.42) and informed caffeine/received placebo (d = 0.43). These changes were associated with an increased pace during the first half of the trial. No differences were shown in pacing or performance between baseline and the informed placebo/received caffeine (d = 0.21) and informed placebo/received placebo (d = 0.10). No differences were reported between treatments for peak heart rate (η2 = .084) and rating of perceived exertion (η2 = .009). CONCLUSIONS The results indicate that the effect of believing to have ingested caffeine improved performance to the same magnitude as actually receiving caffeine. These improvements were associated with an increase in pace during the first half of the time trial.
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94
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Haugen TA, Breitschädel F, Seiler S. Sprint mechanical properties in soccer players according to playing standard, position, age and sex. J Sports Sci 2020; 38:1070-1076. [DOI: 10.1080/02640414.2020.1741955] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Thomas A. Haugen
- School of Health Sciences, Kristiania University College, Oslo, Norway
| | - Felix Breitschädel
- Norwegian Olympic Federation, Oslo, Norway
- Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, Trondheim, Norway
| | - Stephen Seiler
- Faculty of Health and Sport Sciences, University of Agder, Kristiansand, Norway
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95
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Linke D, Link D, Lames M. Football-specific validity of TRACAB's optical video tracking systems. PLoS One 2020; 15:e0230179. [PMID: 32155220 PMCID: PMC7064167 DOI: 10.1371/journal.pone.0230179] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 02/24/2020] [Indexed: 11/19/2022] Open
Abstract
The present study aimed to validate and compare the football-specific measurement accuracy of two optical tracking systems engineered by TRACAB. The “Gen4” system consists of two multi-camera units (a stereo pair) in two locations either side of the halfway line, whereas the distributed “Gen5” system combines two stereo pairs on each side of the field as well as two monocular systems behind the goal areas. Data were collected from 20 male football players in two different exercises (a football sport-specific running course and small-sided games) in a professional football stadium. For evaluating the accuracy of the systems, measures were compared against simultaneously recorded measures of a reference system (VICON motion capture system). Statistical analysis uses RMSE for kinematic variables (position, speed and acceleration) and the difference in percentages for performance indicators (e.g. distance covered, peak speed) per run compared to the reference system. Frames in which players were obviously not tracked were excluded. Gen5 had marginally better accuracy (0.08 m RMSE) for position measurements than Gen4 (0.09 m RMSE) compared to the reference. Accuracy difference in instantaneous speed (Gen4: 0.09 m⋅s-1 RMSE; Gen5: 0.08 m⋅s-1 RMSE) and acceleration (Gen4: 0.26 m⋅s-2 RMSE; Gen5: 0.21 m⋅s-2 RMSE) measurements were significant, but also trivial in terms of the effect size. For total distance travelled, both Gen4 (0.42 ± 0.60%) and Gen5 (0.27 ± 0.35%) showed only trivial deviations compared to the reference. Gen4 showed moderate differences in the low-speed distance travelled category (-19.41 ± 13.24%) and small differences in the high-speed distance travelled category (8.94 ± 9.49%). Differences in peak speed, acceleration and deceleration were trivial (<0.5%) for both Gen4 and Gen5. These findings suggest that Gen5’s distributed camera architecture has minor benefits over Gen4’s single-view camera architecture in terms of accuracy. We assume that the main benefit of the Gen5 towards Gen4 lies in increased robustness of the tracking when it comes to optical overlapping of players. Since differences towards the reference system were very low, both TRACAB’s tracking systems can be considered as valid technologies for football-specific performance analyses in the settings tested as long as players are tracked correctly.
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Affiliation(s)
- Daniel Linke
- Chair of Performance Analysis and Sports Informatics, Technical University Munich, Munich, Germany
- * E-mail:
| | - Daniel Link
- Chair of Performance Analysis and Sports Informatics, Technical University Munich, Munich, Germany
| | - Martin Lames
- Chair of Performance Analysis and Sports Informatics, Technical University Munich, Munich, Germany
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96
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Kramer M, Thomas EJ, Pettitt RW. Critical speed and finite distance capacity: norms for athletic and non-athletic groups. Eur J Appl Physiol 2020; 120:861-872. [PMID: 32086601 DOI: 10.1007/s00421-020-04325-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 02/12/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE Two parameters in particular span both health and performance; critical speed (CS) and finite distance capacity (D'). The purpose of the present study was to: (1) classify performance norms, (2) distinguish athletic from non-athletic individuals using the 3-min all-out test (3MT) for running, and (3) introduce a deterministic model highlighting the relationship between variables of the 3MT. METHODS Athletic (n = 43) and non-athletic (n = 25) individuals participated in the study. All participants completed a treadmill graded exercise test (GXT) with verification bout and a 3MT on an outdoor sprinting track. RESULTS Meaningful differences between non-athletic and athletic individuals (denoted by mean difference scores, p value and Cohen's d with 95% confidence intervals) were evident for CS (- 0.74 m s-1, p < 0.001, d = - 1.41 [1.97, - 0.87]), exponential growth time constant ([Formula: see text]; 2.75 s, p < 0.001, d = - 1.29 [- 1.45, - 0.42]), time to maximal speed ([Formula: see text]; - 2.80 s, p < 0.001, d = - 0.98 [- 1.51, - 0.47]), maximal speed ([Formula: see text]; - 1.36 m s-1, p < 0.001, d = - 1.56 [- 2.13, - 1.01]), gas exchange threshold (GET; - 5.62 ml kg-1 min-1, p < 0.001, d = - 0.97 [- 1.50, - 0.45]), distance covered in the first minute (1st min; - 81.69 m, p < 0.001, d = - 1.91 [- 2.52, - 1.33]), distance covered in the second minute (2nd min; - 52.02 m, p < 0.001, d = - 1.71 [- 2.30, - 1.15]) and maximal distance (- 153.78 m, p < 0.001, d = - 1.27 [- 1.82, - 0.74]). The correlation coefficient between key physiological and performance variables are shown in the form of a deterministic model created from the data derived from the 3MT. CONCLUSIONS Coaches and clinicians may benefit from the use of normative data to potentially identify exceptional or irregular occurrences in 3MT performances.
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Affiliation(s)
- Mark Kramer
- Department of Human Movement Science, Nelson Mandela University, University Way, Summerstrand, Port Elizabeth, 6001, South Africa.
- Physical Activity, Sport and Recreation (PhaSRec), North West University, Potchefstroom, South Africa.
| | - E J Thomas
- Department of Human Movement Science, Nelson Mandela University, University Way, Summerstrand, Port Elizabeth, 6001, South Africa
| | - R W Pettitt
- Rocky Mountain University of Health Professions, Provo, UT, USA
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97
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Gastin PB, Hunkin SL, Fahrner B, Robertson S. Deceleration, Acceleration, and Impacts Are Strong Contributors to Muscle Damage in Professional Australian Football. J Strength Cond Res 2020; 33:3374-3383. [PMID: 30694964 DOI: 10.1519/jsc.0000000000003023] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Gastin, PB, Hunkin, SL, Fahrner, B, and Robertson, S. Deceleration, acceleration, and impacts are strong contributors to muscle damage in professional Australian football. J Strength Cond Res 33(12): 3374-3383, 2019-The purpose of this study was to investigate the relationships between serum creatine kinase [CK], an indirect marker of muscle damage, and specific indices of match load in elite Australian football. Twenty-six professional players were assessed during a competitive Australian Football League (AFL) season. [CK] was collected 24-36 hours before match and 34-40 hours after match during 8 in-season rounds. An athlete-tracking technology was used to quantify match load. Generalized estimating equations and random forest models were constructed to determine the extent to which match-load indices and pre-match [CK] explained post-match [CK]. There was a 129 ± 152% increase in [CK] in response to AFL competition. Generalized estimating equations found that number of impacts >3g (p = 0.004) and game time (p = 0.016) were most strongly associated with post-match [CK]. Random forest, with considerably lower errors (130 vs. 316 U·L), found deceleration, acceleration, impacts >3g, and sprint distance to be the strongest predictors. Pre-match [CK] accounted for 11% of post-match [CK], and considerable interindividual and intraindividual variability existed in the data. Creatine kinase, an indicator of muscle damage, was considerably elevated as a result of AFL competition. Parametric and machine-learning analysis techniques found several indices of physical load associated with muscle damage during competition, with impacts >3g and high-intensity running variables as the strongest predictors. [CK] may be used as a global measure of muscle damage in field team sports such as AF, yet with some caution given cost, invasiveness, and inherent variability. Quantifying physical load and the responses to that load can guide athlete management decision-making and is best undertaken within a suite of practical, sport-specific measures, where data are interpreted individually and with an understanding of the limitations.
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Affiliation(s)
- Paul B Gastin
- La Trobe Sport and Exercise Medicine Research Center, School of Allied Health, La Trobe University, Melbourne, Victoria, Australia
| | - Shannon L Hunkin
- Center for Sport Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
| | - Brendan Fahrner
- Department of Dietetics, Human Nutrition and Sport, Richmond Football Club, Melbourne, Victoria, Australia
| | - Sam Robertson
- Institute of Health and Sport, College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia
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98
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Effects of Plyometric Versus Optimum Power Load Training on Components of Physical Fitness in Young Male Soccer Players. Int J Sports Physiol Perform 2020; 15:222-230. [DOI: 10.1123/ijspp.2019-0039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 04/26/2019] [Accepted: 04/29/2019] [Indexed: 11/18/2022]
Abstract
Purpose: The current study aimed to compare the effects of plyometric (PT) versus optimum power load (OPL) training on physical performance of young high-level soccer players. Methods: Athletes were randomly divided into PT (horizontal and vertical drills) and OPL (squat + hip thrust exercises at the load of maximum power output) interventions, applied over 7 weeks during the in-season period. Squat and countermovement jumps, maximal sprint (10 and 30 m), and change of direction (COD; agility t test) were the pretraining and posttraining measured performance variables. Magnitude-based inference was used for within- and between-group comparisons. Results: OPL training induced moderate improvements in vertical squat jump (effect size [ES]: 0.97; 90% confidence interval [CI], 0.32–1.61) and countermovement jump (ES: 1.02; 90% CI, 0.46–1.57), 30-m sprint speed (ES: 1.02; 90% CI, 0.09–1.95), and COD performance (ES: 0.93; 90% CI, 0.50–1.36). After PT training method, vertical squat jump (ES: 1.08; 90% CI, 0.66–1.51) and countermovement jump (ES: 0.62; 90% CI, 0.18–1.06) were moderately increased, while small enhancements were noticed for 30-m sprint speed (ES: 0.21; 90% CI, −0.02 to 0.45) and COD performance (ES: 0.53; 90% CI, 0.24–0.81). The 10-m sprint speed possibly increased after PT intervention (small ES: 0.25; 90% CI, −0.05 to 0.54), but no substantial change (small ES: 0.36; 90% CI, −0.40 to 1.13) was noticed in OPL. For between-group analyses, the COD ability and 30-m sprint performances were possibly (small ES: 0.30; 90% CI, −0.20 to 0.81; Δ = +1.88%) and likely (moderate ES: 0.81; 90% CI, −0.16 to 1.78; Δ = +2.38%) more improved in the OPL than in the PT intervention, respectively. Conclusions: The 2 different training programs improved physical performance outcomes during the in-season period. However, the combination of vertically and horizontally based training exercises (squat + hip thrust) at optimum power zone led to superior gains in COD and 30-m linear sprint performances.
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99
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Supej M, Spörri J, Holmberg HC. Methodological and Practical Considerations Associated With Assessment of Alpine Skiing Performance Using Global Navigation Satellite Systems. Front Sports Act Living 2020; 1:74. [PMID: 33344996 PMCID: PMC7739811 DOI: 10.3389/fspor.2019.00074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 12/24/2019] [Indexed: 12/20/2022] Open
Abstract
Reliable assessment of the performance of alpine skiers is essential. Previous studies have highlighted the potential of Global Navigation Satellite Systems (GNSS) for evaluating this performance. Accordingly, the present perspective summarizes published research concerning methodological and practical aspects of the assessment of alpine skiing performance by GNSS. Methodologically, in connection with trajectory analysis, a resolution of 1-10 cm, which can be achieved with the most advanced GNSS systems, has proven to provide acceptable accuracy. The antenna should be positioned to follow the trajectory of the skier's center-of-mass (CoM) as closely as possible and estimation of this trajectory can be further improved by applying advanced modeling and/or other computerized approaches. From a practical point of view, effective assessment requires consideration of numerous parameters related to performance, including gate-to-gate times, trajectory, speed, and energy dissipation. For an analysis that is both more comprehensive and more easily accessible to coaches/athletes, video filming should be synchronized with the GNSS data. In summary, recent advances in GNSS technology already allow, at least to some extent, precise biomechanical analysis of performance over an entire alpine skiing race course in real-time. Such feedback has both facilitated and improved the work of coaches. Thus, athletes and coaches are becoming more and more aware of the advantages of analyzing alpine skiing performance by GNSS in combination with advanced computer software, paving the way for the digital revolution in both the applied research on and practice of this sport.
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Affiliation(s)
- Matej Supej
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Jörg Spörri
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Hans-Christer Holmberg
- Swedish Winter Sports Research Center, Mid Sweden University, Östersund, Sweden.,China Institute of Sport and Health Science, Beijing Sport University, Beijing, China
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100
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Cuthbert M, Thomas C, DosʼSantos T, Jones PA. Application of Change of Direction Deficit to Evaluate Cutting Ability. J Strength Cond Res 2019; 33:2138-2144. [PMID: 31344010 DOI: 10.1519/jsc.0000000000002346] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cuthbert, M, Thomas, C, Dos'Santos, T, and Jones, PA. Application of change of direction deficit to evaluate cutting ability. J Strength Cond Res 33(8): 2138-2144, 2019-The purpose of this study was to examine the application of the change of direction deficit (CODD) to a 90° cut test to examine whether CODD provides a unique evaluation of an individual's cutting ability. Thirty-six male collegiate team-sport (23 Rugby/13 Soccer) athletes (age: 20 ± 1.4 years; height: 1.80 ± 0.08 m; mass: 83 ± 13.2 kg) participated in the study. Each athlete performed 3 trials of a 20-m sprint (with 5 and 10 m splits) and 2 change of direction (COD) tests (90° cut and 505 tests) cutting/turning from both legs. Completion times for all sprint and COD tests were measured using timing cells. For both COD tests, CODD was determined (COD completion time-10 m sprint time). Pearson correlation was used to explore the relationships between sprint times and CODD and completion times. Significant (p < 0.001) moderate-to-large (r ≥ 0.467) correlations between sprint times and 90° cut completion times for left and right cuts were observed. Nonsignificant (p > 0.05) trivial-to-small correlations (r ≤ 0.199) were found between sprint variables and 90° cut CODD. Significant (p < 0.001) large to very large correlations (r ≥ 0.531) were revealed between the left and right 90° cut and 90° cut CODD. The results suggest that the CODD could be applied to isolate and assess the cutting ability in COD speed tests that involve a single cutting maneuver. Failure to inspect CODD could lead to incorrect evaluation of an athletes cutting or COD ability.
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Affiliation(s)
- Matthew Cuthbert
- Directorate of Sport, Exercise and Physiotherapy, University of Salford, Salford, Greater Manchester, United Kingdom
| | - Christopher Thomas
- Directorate of Sport, Exercise and Physiotherapy, University of Salford, Salford, Greater Manchester, United Kingdom.,School of Health, Sport and Professional Practice, University of South Wales, Pontypridd, Wales, United Kingdom
| | - Thomas DosʼSantos
- Directorate of Sport, Exercise and Physiotherapy, University of Salford, Salford, Greater Manchester, United Kingdom
| | - Paul A Jones
- Directorate of Sport, Exercise and Physiotherapy, University of Salford, Salford, Greater Manchester, United Kingdom
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