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Kurtoğlu A, Eken Ö, Çiftçi R, Çar B, Dönmez E, Kılıçarslan S, Jamjoom MM, Samee NA, Hassan DSM, Mahmoud NF. The role of morphometric characteristics in predicting 20-meter sprint performance through machine learning. Sci Rep 2024; 14:16593. [PMID: 39025965 PMCID: PMC11258122 DOI: 10.1038/s41598-024-67405-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 07/10/2024] [Indexed: 07/20/2024] Open
Abstract
The aim of this study was to test the morphometric features affecting 20-m sprint performance in children at the first level of primary education using machine learning (ML) algorithms. In this study, 130 male and 152 female volunteers aged between 6 and 11 years were included. After obtaining demographic information of the participants, skinfold thickness, diameter and circumference measurements, and 20-m sprint performance were determined. The study conducted three distinct experiments to determine the optimal ML technique for predicting outcomes. Initially, the entire feature space was utilized for training the ML models to establish a baseline performance. In the second experiment, only significant features identified through correlation analysis were used for training and testing the models, enhancing the focus on relevant predictors. Lastly, Principal Component Analysis (PCA) was employed to reduce the feature space, aiming to streamline model complexity while retaining data variance. These experiments collectively aimed to evaluate different feature selection and dimensionality reduction techniques, providing insights into the most effective strategies for optimizing predictive performance in the given context. The correlation-based selected features (Age, Height, waist circumference, hip circumference, leg length, thigh length, foot length) has produced a minimum Mean Squared Error (MSE) value of 0.012 for predicting the sprint performance in children. The effective utilization of correlation analysis in the selection of relevant features for our regression model suggests that the features selected exhibit robust linear associations with the target variable and can be relied upon as predictors.
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Affiliation(s)
- Ahmet Kurtoğlu
- Department of Coaching Education, Faculty of Sport Science, Bandirma Onyedi Eylul University, Balıkesir, 10200, Turkey
| | - Özgür Eken
- Department of Physical Education and Sport Teaching, Faculty of Sports Sciences, Inonu University, Malatya, Turkey
| | - Rukiye Çiftçi
- Department of Anatomy, Medical Faculty, Gaziantep Islamıc Science and Technology University, Gaziantep, Turkey
| | - Bekir Çar
- Department of Physical Education and Sport Teaching, Faculty of Sport Sciences, Bandirma Onyedi Eylul University, Balıkesir, 10200, Turkey
| | - Emrah Dönmez
- Department of Software Engineering, Bandırma Onyedi Eylül University, Balıkesir, Turkey
| | - Serhat Kılıçarslan
- Department of Software Engineering, Bandırma Onyedi Eylül University, Balıkesir, Turkey
| | - Mona M Jamjoom
- Department of Computer Sciences, College of Computer and Information Sciences, Princess Nourah Bint Abdulrahman University, 11671, Riyadh, Saudi Arabia
| | - Nagwan Abdel Samee
- Department of Information Technology, College of Computer and Information Sciences, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, 11671, Riyadh, Saudi Arabia.
| | - Dina S M Hassan
- Department of Information Technology, College of Computer and Information Sciences, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, 11671, Riyadh, Saudi Arabia
| | - Noha F Mahmoud
- Rehabilitation Sciences Department, Health and Rehabilitation Sciences College, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, 11671, Riyadh, Saudi Arabia
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Zabaloy S, Freitas TT, Alcaraz PE, Gálvez-González J, Pereira LA, Comyns T, Loturco I, Healy R. Relative Acceleration and Maximum Velocity in Rugby Players According to Age Category and Playing Position. J Strength Cond Res 2024:00124278-990000000-00478. [PMID: 39016269 DOI: 10.1519/jsc.0000000000004861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
ABSTRACT Zabaloy, S, Freitas, TT, Alcaraz, PE, Gálvez-González, J, Pereira, LA, Comyns, T, Loturco, I, and Healy, R. Relative acceleration and maximum velocity in rugby players according to age category and playing position. J Strength Cond Res XX(X): 000-000, 2024-This study aimed to: (a) assess the intrasession reliability of the acceleration time constant (i.e., τ) and τ-derived measures; (b) analyze the influence of τ and maximum velocity (Vmax) on 40-m sprint performance and to compare various sprint-related outcomes among rugby players from different playing positions and age categories; and (c) explore the associations between τ and several sprint performance metrics. A total of 300 male rugby players volunteered to participate in this study and were divided into age categories (i.e., under-14 [U14]: n = 91, age: 12.6 ± 0.5 years; under-16 [U16]: n = 85, age: 14.8 ± 0.5 years; under-18 [U18]: n = 75, age: 16.6 ± 0.5 years; and Seniors: n = 49, age: 24.2 ± 4.1 years). The results demonstrated good to excellent reliability for all measured parameters (intraclass correlation coefficient >0.75 and coefficient of variation <9.0%). Younger players (i.e., U14 and U16) displayed lower τ values (effect size: moderate to large; p < 0.02) compared with their older peers (i.e., U18 and Seniors), regardless of their playing position. Moreover, τ was associated with sprint performance metrics at varying levels of correlations (Rho: small to almost perfect; p < 0.001). In conclusion, younger players exhibited lower τ values than their older counterparts, irrespective of their playing positions. The model employed in this study demonstrated its accuracy in assessing several key sprint performance metrics, offering insights that can enhance sprint training programs for rugby players, which can be based on the associations observed among these different variables.
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Affiliation(s)
- Santiago Zabaloy
- Faculty of Physical Activity and Sports, University of Flores, Buenos Aires, Argentina
- Carnegie School of Sports, Leeds Beckett University, Leeds, United Kingdom
| | - Tomás T Freitas
- UCAM Research Center for High Performance Sport, UCAM Universidad Católica de Murcia, Murcia, Spain
- Nucleus of High Performance in Sport (NAR), São Paulo, Brazil
- Facultad de Deporte, UCAM Universidad Católica de Murcia, Murcia, Spain
| | - Pedro E Alcaraz
- UCAM Research Center for High Performance Sport, UCAM Universidad Católica de Murcia, Murcia, Spain
| | | | - Lucas A Pereira
- Nucleus of High Performance in Sport (NAR), São Paulo, Brazil
- Department of Human Movement Sciences, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Tom Comyns
- Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland
| | - Irineu Loturco
- Nucleus of High Performance in Sport (NAR), São Paulo, Brazil
- Department of Human Movement Sciences, Federal University of Sao Paulo, Sao Paulo, Brazil
- University of South Wales, Pontypridd, Wales, United Kingdom; and
| | - Robin Healy
- Department of Sport and Health Sciences, Athlone Institute of Technology, Ireland
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Cerrillo-Sanchis J, Ricart-Luna B, Rodrigo-Mallorca D, Muñoz-Gómez E, Domínguez-Navarro F, Mollà-Casanova S, Chulvi-Medrano I. Relationship between ankle dorsiflexion range of motion and sprinting and jumping ability in young athletes. J Bodyw Mov Ther 2024; 39:43-49. [PMID: 38876663 DOI: 10.1016/j.jbmt.2024.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/22/2024] [Accepted: 02/25/2024] [Indexed: 06/16/2024]
Abstract
OBJECTIVES To investigate the relationship between predicted risk of injury based on the dichotomous classification of the weight-bearing lunge (WBL) test scores and variables related to jumping and sprinting ability in young athletes. Furthermore, to compare the impact of the classical dichotomous classification versus a more specific quartile subdivision of the WBL test scores on the explored variables. DESIGN Cross-sectional study. PARTICIPANTS 125 healthy athletes (mean age 10.38 (SD = 2.28) years) were recruited. MAIN OUTCOME MEASURES Ankle dorsiflexion was evaluated with the WBL test, jumping distance with the standing long jump (SLJ) test, and maximal running speed with the 14-m and 28-m sprint test. RESULTS Athletes with WBL test scores lower than 10 cm exhibited significantly poorer results for the SLJ test as well as lower 14-m and 28-m sprint times than those with WBL test scores higher than 10 cm (p < 0.05). Likewise, when WBL test scores were subdivided by quartiles, a positive trend between range of motion and improved performance was shown. CONCLUSIONS Reduced ankle dorsiflexion mobility may affect sprinting and jumping ability in young athletes. In addition, a more detailed classification of ankle restriction by quartiles is proposed in this study in order to prevent injury and enhance athletic performance.
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Affiliation(s)
| | | | - Darío Rodrigo-Mallorca
- Sport Performance and Physical Fitness Research Group (UIRFIDE), Physical Education and Sport Department, University of Valencia, Valencia, Spain
| | - Elena Muñoz-Gómez
- UBIC. Department of Physiotherapy, Faculty of Physiotherapy, University of Valencia, Spain
| | - Fernando Domínguez-Navarro
- Physiotherapy, Faculty of Health Sciences, European University of Valencia, 46010, Valencia, Spain; Department of Physiotherapy, University of Valencia, Calle Gascó Oliag 5, 46010, Valencia, Spain
| | - Sara Mollà-Casanova
- UBIC. Department of Physiotherapy, Faculty of Physiotherapy, University of Valencia, Spain.
| | - Iván Chulvi-Medrano
- Sport Performance and Physical Fitness Research Group (UIRFIDE), Physical Education and Sport Department, University of Valencia, Valencia, Spain
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Whyte E, O’Connor S, Tobin Jones H, McBride C, O’Flynn A, Quinn O, Behan F. The relationship between hamstring strength tests and sprint performance in female Gaelic footballers: A correlation and linear regression analysis. PLoS One 2024; 19:e0302901. [PMID: 38857230 PMCID: PMC11164353 DOI: 10.1371/journal.pone.0302901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 04/16/2024] [Indexed: 06/12/2024] Open
Abstract
OBJECTIVES To investigate the relationships between handheld dynamometer (HHD), isokinetic and Nordic hamstrings exercise (NHE) measurements of knee flexor strength and their association with sprinting performance. DESIGN Cross-sectional. METHODS The relationships between HHD (prone isometric, prone break and supine break knee flexor strength tests), isokinetic and NHE peak knee flexor strength measures were examined using Pearson product correlations on 38 female footballers. A linear regression analysis was also performed for each pair of dependent variables (10 and 30 metre sprint times) and independent predictor variables (average relative peak torque for HHD, isokinetic and NHE testing). RESULTS There were good correlations between HHD tests (r = 0.81-0.90, p < 0.001, R2 = 0.65-0.82), moderate correlations between HHD and isokinetic peak torque, (r = 0.61-0.67, p < 0.001, R2 = 0.37-0.44) and poor association between the HHD peak torques and isokinetic work (r = 0.44-0.46, p = 0.005-0.007, R2 = 0.20-0.21) and average power (r = 0.39-0.45, n = 36, p = 0.006-0.019, R2 = 0.15-0.22). There was a poor association between NHE peak torque and isokinetic total work (r = 0.34, p = 0.04, R2 = 0.12). No associations between knee flexor strength and sprint times were observed (p = 0.12-0.79, r2 = 0.002-0.086). CONCLUSIONS Moderate to good correlations within HHD testing and poor to moderate correlations between HHD and isokinetic testing were observed. HHD knee flexor torque assessment may be useful to regularly chart the progress of hamstring rehabilitation for female footballers. Knee flexor strength assessments were not associated with sprint times in female footballers. Other aspects of knee flexor strength and sprint performance should be investigated to assist clinicians in making return to running and sprinting decisions in this population.
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Affiliation(s)
- Enda Whyte
- School of Health and Human Performance, Dublin City University, Dublin, Ireland
- Centre for Injury Prevention and Performance, Ireland
| | - Siobhán O’Connor
- School of Health and Human Performance, Dublin City University, Dublin, Ireland
- Centre for Injury Prevention and Performance, Ireland
| | - Hannah Tobin Jones
- School of Health and Human Performance, Dublin City University, Dublin, Ireland
| | - Cian McBride
- School of Health and Human Performance, Dublin City University, Dublin, Ireland
| | - Aisling O’Flynn
- School of Health and Human Performance, Dublin City University, Dublin, Ireland
| | - Oisin Quinn
- School of Health and Human Performance, Dublin City University, Dublin, Ireland
| | - Fearghal Behan
- Department of Bioengineering, Imperial College London, London, United Kingdom
- Discipline of Physiotherapy, Trinity College Dublin, Dublin, Ireland
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Tong TH, Wang GW. Anthropometric and physical fitness indicators in the combine draft between the finalist and the eliminated player in the national basketball association all-star slam dunk contest. PLoS One 2024; 19:e0299262. [PMID: 38427631 PMCID: PMC10906826 DOI: 10.1371/journal.pone.0299262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 02/07/2024] [Indexed: 03/03/2024] Open
Abstract
Little is known about the difference of anthropometry and physical fitness between the finalist and eliminated player in the NBA all star slam dunk contest. This study aimed to compare the difference on anthropometric and physical fitness indicator in the combine draft between finalist and eliminated player in the national basketball association all star slam dunk contest. Draft data of 32 basketball players (N = 32, age in draft year: 20.69±2.28 years old, height without shoes: 196.75±8.68 cm, weight: 96.85±10 kg, body fat percentage: 6.07±1.23%) participating in the 2000-2015 draft and 2003-2023 slam dunk contest was selected from national basketball association database. It was classified into finals group (FG) (N = 16) and elimination group (EG) (N = 16). Independent sample t-test with cohen's d was adopted for evaluating the statistical significance of intergroup difference and its effect size. The result indicates that Finalist group was significant less than elimination group on height without shoes (FG vs EG: 193.43±9.47 cm vs 200.06±6.52 cm, P<0.05), standing reach (FG vs EG: 257.66±12.32 cm vs 268.29±10.03 cm, P<0.05) and weight (FG vs EG: 93.38±7.37 kg vs 100.33±11.25 kg, P<0.05). Conversely, compared to elimination group,finalist group has significant better performance on three quarter court sprint (FG vs EG: 3.15±0.1 s vs 3.26±0.12 s, P<0.05), standing vertical jump (FG vs EG: 84.88±5.13 cm vs 78.83±4.9 cm, P<0.05) and max vertical jump (FG vs EG: 102.39±6.47 cm vs 94.79±8.34 cm, P<0.05). However, effect size analysis indicated that height without shoes,standing reach,weight (cohen's d = 0.73-0.959, 0.7≤cohen's d<1.3, moderate) from the anthropometric indicator and three quarter court sprint, standing vertical jump, and max vertical jump (cohen's d = 0.97-1.21, 0.7≤cohen's d<1.3, moderate) from physical fitness indicator has moderate effect size, whereas effect size of body fat percentage, wingspan and lane agility time (cohen's d = 0.31-0.67, 0.3≤cohen's d<0.7, small) was small. To conclude, specific anthropometric and physical fitness indicator shows clear difference between finals group and elimination group. Height without shoes, standing reach,weight in anthropometry and three quarter court sprint, standing vertical jump, and max vertical jump in physical fitness are key indicator to slam dunk performance. In line with the result in the study, NBA staff can select suitable rookies for slam dunk contest. Similiarly, coach from NBA or other basketball league, who want to improve the player's slam dunk performance, should use specific training programs to develop the slam dunk-related indicator.
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Affiliation(s)
- Tse-hau Tong
- Department of Astronautical Science and Mechanics, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Guo-wei Wang
- Strength and Conditioning and Sport Performance Lab, Institute of Physical Education, Zhengzhou University, Zhengzhou, Henan, China
- Institute of Physical Education, Zhengzhou University, Zhengzhou, Henan, China
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Hamad MJ, Alcaraz PE, de Villarreal ES. Effects of Combined Uphill-Downhill Sprinting Versus Resisted Sprinting Methods on Sprint Performance: A Systematic Review and Meta-analysis. Sports Med 2024; 54:185-202. [PMID: 37658966 DOI: 10.1007/s40279-023-01916-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2023] [Indexed: 09/05/2023]
Abstract
BACKGROUND Two specific sprint training methods that are present to varying degrees in research and practice are combined uphill-downhill sprinting (UDS) and resisted sprint training methods (RS). Both methods seem to improve sprint performance, but to the author's knowledge a comparison does not exist investigating the differences between the two training protocols and traditional sprinting. OBJECTIVE The present systematic review and meta-analysis investigated sprint performance changes between combined uphill-downhill sprinting and resisted sprinting methods (sleds, cables/bands, vests, uphill) and how these compared with traditional sprinting. METHODS A literature search was performed on 19 December 2022, in the databases PubMed, SPORTDiscus, Web of Science and SCOPUS, which from 22 studies yielded a total of 24 eligible groups (UDS, n = 6; RS, n = 18). Studies that measured sprint performance, had a traditional sprinting control, and used either training intervention in healthy individuals of any age for ≥ 4 weeks were eligible for the meta-analysis. The change in sprint performance from baseline to post intervention was compared between the interventions and their traditional sprinting control group. Outcomes were expressed as standardized mean differences (SMD). RESULTS The standardized changes in sprint performance between intervention groups and traditional-sprinting controls (negative in favour of intervention, positive in favour of traditional sprint) and 95% confidence interval (CI) were as follows: small for UDS (SMD - 0.41 [- 0.79, - 0.03]; p = 0.03), trivial for RS (SMD - 0.14 [- 0.36, 0.07]; p = 0.19). CONCLUSION Combined uphill-downhill sprinting was more effective than traditional sprinting, while resisted sprinting was not. It appears that resisted sprint interventions do not increase sprint performance any more than traditional sprinting. Subgroup analysis and meta-regression appear to show differences between sled loads and possible differences across distances tested. The results of this review and meta-analysis seem to warrant further investigations into the possibility that UDS may be a superior sprint training method to resisted and traditional sprinting.
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Affiliation(s)
- Maziar J Hamad
- UCAM Research Center for High Performance Sport-Catholic University of Murcia (UCAM), Murcia, Spain.
| | - Pedro E Alcaraz
- UCAM Research Center for High Performance Sport-Catholic University of Murcia (UCAM), Murcia, Spain
- Faculty of Sport Sciences, Catholic University of Murcia (UCAM), Murcia, Spain
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Loturco I, Freitas TT, Zabaloy S, Pereira LA, Moura TBMA, Fernandes V, Mercer VP, Alcaraz PE, Zając A, Bishop C. Speed Training Practices of Brazilian Olympic Sprint and Jump Coaches: Toward a Deeper Understanding of Their Choices and Insights (Part II). J Hum Kinet 2023; 89:187-211. [PMID: 38053953 PMCID: PMC10694730 DOI: 10.5114/jhk/174071] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 10/16/2023] [Indexed: 12/07/2023] Open
Abstract
This is the second article in a three-article collection regarding the plyometric, speed, and resistance training practices of Brazilian Olympic sprint and jump coaches. Here, we list and describe six out of the ten speed training methods most commonly employed by these experts to enhance the sprinting capabilities of their athletes. Maximum speed sprinting, form running, resisted sprinting, overspeed running, uphill and downhill running, and sport-specific movement methods are critically examined with reference to their potential application in different sport contexts. In an era when sprint speed is of critical importance across numerous sports, practitioners can employ the methods outlined here to design efficient training programs for their athletes.
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Affiliation(s)
- Irineu Loturco
- NAR—Nucleus of High Performance in Sport, São Paulo, Brazil
- Department of Human Movement Sciences, Federal University of São Paulo, São Paulo, Brazil
- Department of Sport, Health, and Exercise Science, University of South Wales, Pontypridd, Wales, United Kingdom
| | - Tomás T. Freitas
- NAR—Nucleus of High Performance in Sport, São Paulo, Brazil
- Department of Human Movement Sciences, Federal University of São Paulo, São Paulo, Brazil
- UCAM Research Center for High Performance Sport, UCAM Universidad Católica de Murcia, Murcia, Spain
- Facultad de Deporte, UCAM Universidad Católica de Murcia, Murcia, Spain
| | - Santiago Zabaloy
- Faculty of Physical Activity and Sports, University of Flores, Buenos Aires, Argentina
| | | | | | | | | | - Pedro E. Alcaraz
- UCAM Research Center for High Performance Sport, UCAM Universidad Católica de Murcia, Murcia, Spain
| | - Adam Zając
- Institute of Sport Sciences, The Jerzy Kukuczka Academy of Physical Education in Katowice, Katowice, Poland
| | - Chris Bishop
- London Sport Institute, Middlesex University, London, United Kingdom
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Loturco I, Pereira LA, Freitas TT, Moura TBMA, Mercer VP, Fernandes V, Moura NSA, Moura NA, Zając A, Bishop C. Plyometric Training Practices of Brazilian Olympic Sprint and Jump Coaches: Toward a Deeper Understanding of Their Choices and Insights. J Hum Kinet 2023; 87:131-150. [PMID: 37559773 PMCID: PMC10407309 DOI: 10.5114/jhk/169167] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 06/12/2023] [Indexed: 08/11/2023] Open
Abstract
Plyometric training is extensively used by coaches to enhance neuromuscular performance in a wide variety of sports. Due to the high demands of sprint speed and power output in elite sprinters and jumpers, sprint and jump coaches are likely to have great knowledge on this topic. Undoubtedly, this expertise is even more pronounced for Olympic coaches, who work with some of the fastest and most powerful athletes in the world, and who are required to continually maintain these athletes at optimal performance levels. Describing and discussing the practices commonly adopted by these coaches in detail and extrapolating this experience to other sport coaching contexts and disciplines may be extremely relevant. The current article presents, explores, and illustrates the plyometric training practices of Brazilian Olympic sprint and jump coaches, with a special focus on training programming and exercise selection.
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Affiliation(s)
- Irineu Loturco
- NAR—Nucleus of High Performance in Sport, São Paulo, Brazil
- Department of Human Movement Sciences, Federal University of São Paulo, São Paulo, Brazil
- University of South Wales, Pontypridd, Wales, United Kingdom
| | - Lucas A. Pereira
- NAR—Nucleus of High Performance in Sport, São Paulo, Brazil
- Department of Human Movement Sciences, Federal University of São Paulo, São Paulo, Brazil
| | - Tomás T. Freitas
- NAR—Nucleus of High Performance in Sport, São Paulo, Brazil
- Department of Human Movement Sciences, Federal University of São Paulo, São Paulo, Brazil
- UCAM Research Center for High Performance Sport, UCAM Universidad Católica de Murcia, Murcia, Spain
- Facultad de Deporte, UCAM Universidad Católica de Murcia, Murcia, Spain
| | | | | | | | | | - Nélio A. Moura
- Pinheiros Sport Club, São Paulo, Brazil
- Chinese Athletics Association, Beijing, China
| | - Adam Zając
- Institute of Sport Sciences, The Jerzy Kukuczka Academy of Physical Education in Katowice, Katowice, Poland
| | - Chris Bishop
- London Sport Institute, Middlesex University, London, United Kingdom
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Strength and Conditioning Practices of Brazilian Olympic Sprint and Jump Coaches. J Hum Kinet 2023; 86:175-194. [PMID: 37181261 PMCID: PMC10170547 DOI: 10.5114/jhk/159646] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Olympic coaches are likely to have adequate knowledge and implement effective training programs. This study aimed to describe and critically examine the strength and conditioning practices adopted by Brazilian Olympic sprint and jump coaches. Nineteen Olympic coaches (age: 50.2 ± 10.8 years; professional experience: 25.9 ± 13.1 years) completed a survey consisting of eight sections: 1) background information; 2) strength-power development; 3) speed training; 4) plyometrics; 5) flexibility training; 6) physical testing; 7) technology use; and 8) programming. It was noticed that coaches prioritized the development of explosiveness, power, and sprinting speed in their training programs, given the specific requirements of sprint and jump events. Nevertheless, unexpectedly, we observed: (1) large variations in the number of repetitions performed per set during resistance training in the off-season period, (2) a higher volume of resistance training prescribed during the competitive period (compared to other sports), and (3) infrequent use of traditional periodization models. These findings are probably related to the complex characteristics of modern competitive sports (e.g., congested competitive schedule) and the individual needs of sprinters and jumpers. Identification of training practices commonly used by leading track and field coaches may help practitioners and sport scientists create more effective research projects and training programs.
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Impact of Sled Loads on Performance and Kinematics of Elite Sprinters and Rugby Players. Int J Sports Physiol Perform 2022; 17:465-473. [PMID: 34965512 DOI: 10.1123/ijspp.2020-0867] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 07/22/2021] [Accepted: 07/22/2021] [Indexed: 11/18/2022]
Abstract
PURPOSE To examine the changes in resisted sprint performance and kinematics provoked by different sled loads in elite sprinters and rugby players. METHODS Eight elite male sprinters and 10 rugby union players performed 20-m sprints under 3 loading conditions (0%, 20%, and 60% body mass [BM]). Sprint time was measured in 0 to 5, 5 to 10, and 10 to 20 m, while stride length and hip, knee, and ankle angles were measured using an 8-sensor motion analysis system at the same distances. RESULTS Sprinters were significantly faster than rugby players in unresisted and resisted sprints using 20% BM (effect size, "ES" [90% confidence limit, CL] range: 0.65 [0.03 to 1.27]; 3.95 [3.10 to 4.81]), but these differences were not significant at 60% BM. Compared to rugby players, sprinters showed lower velocity decrement in resisted sprints using 20% BM (ES [90% CL] range: 0.75 [0.06 to 1.44]; 2.43 [0.83 to 4.02], but higher velocity decrement using 60% BM (ES [90% CL] range: 1.13 [0.43 to 1.82]; 1.46 [0.81 to 2.11]). No significant differences were detected in stride length between sprinters and rugby players for any sprint condition (ES [90% CL] range: 0.02 [-0.72 to 0.76]; 0.84 [0.13 to 1.54]). Rugby players showed higher hip flexion in resisted sprints (ES [90% CL] range: 0.30 [-0.54 to 1.14]; 1.17 [0.20 to 2.15]) and lower plantar flexion in both unresisted and resisted sprints (ES [90% CL] range: 0.78 [0.18 to 1.38]; 1.69 [1.00 to 2.38] than sprinters. CONCLUSIONS The alterations induced by resisted sprints in sprint velocity and running technique differed between sprinters and rugby players. Some caution should be taken with general sled loads prescriptions, especially when relative loads are based on distinct percentages of BM, as training responses vary among sports and individuals.
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Correia JP, Vaz JR, Domingos C, Freitas SR. From thinking fast to moving fast: motor control of fast limb movements in healthy individuals. Rev Neurosci 2022; 33:919-950. [PMID: 35675832 DOI: 10.1515/revneuro-2021-0171] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 05/09/2022] [Indexed: 12/14/2022]
Abstract
The ability to produce high movement speeds is a crucial factor in human motor performance, from the skilled athlete to someone avoiding a fall. Despite this relevance, there remains a lack of both an integrative brain-to-behavior analysis of these movements and applied studies linking the known dependence on open-loop, central control mechanisms of these movements to their real-world implications, whether in the sports, performance arts, or occupational setting. In this review, we cover factors associated with the planning and performance of fast limb movements, from the generation of the motor command in the brain to the observed motor output. At each level (supraspinal, peripheral, and motor output), the influencing factors are presented and the changes brought by training and fatigue are discussed. The existing evidence of more applied studies relevant to practical aspects of human performance is also discussed. Inconsistencies in the existing literature both in the definitions and findings are highlighted, along with suggestions for further studies on the topic of fast limb movement control. The current heterogeneity in what is considered a fast movement and in experimental protocols makes it difficult to compare findings in the existing literature. We identified the role of the cerebellum in movement prediction and of surround inhibition in motor slowing, as well as the effects of fatigue and training on central motor control, as possible avenues for further research, especially in performance-driven populations.
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Affiliation(s)
- José Pedro Correia
- CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1495-751, Cruz Quebrada, Portugal.,Laboratório de Função Neuromuscular, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1495-751, Cruz Quebrada, Portugal
| | - João R Vaz
- CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1495-751, Cruz Quebrada, Portugal.,Laboratório de Função Neuromuscular, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1495-751, Cruz Quebrada, Portugal
| | - Christophe Domingos
- CIEQV, Escola Superior de Desporto de Rio Maior, Instituto Politécnico de Santarém, Av. Dr. Mário Soares nº 110, 2040-413, Rio Maior, Portugal
| | - Sandro R Freitas
- Laboratório de Função Neuromuscular, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1495-751, Cruz Quebrada, Portugal
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12
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Langen G, Sandau I, Ueberschär O, Nosaka K, Behringer M. Methodical approaches to determine the rate of radial muscle displacement using tensiomyography: A scoping review and new reporting guideline. J Electromyogr Kinesiol 2022; 67:102702. [PMID: 36183503 DOI: 10.1016/j.jelekin.2022.102702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 07/30/2022] [Accepted: 08/31/2022] [Indexed: 12/14/2022] Open
Abstract
Tensiomyography is a non-invasive method to assess skeletal muscle contractile properties from the stimulated radial displacement. Many studies have used the rate of displacement (Vc) as an indirect measure of muscle contraction velocity. However, no standardised methodical approach exists to measure displacement and determine Vc. This review aimed to provide an overview of concepts to determine Vc and measurement protocols to foster the development of a standardised methodical approach. This review followed the Preferred Reporting Items for Systematic Reviews and meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guideline. Systematic searches were performed within five electronic databases and additional sources. The included 62 studies reported 10 different concepts to determine Vc, which we summarised in three groups. The determination concepts differed mainly regarding time intervals during the contraction phase considered and criteria used to define these intervals. Essential information on the equipment and raters, measurement setup, electrical stimulation procedure, and data analysis were frequently not reported. In conclusion, no consensus on how to determine Vc existed. Incomplete reporting of measurement protocols hindered study comparison, which obstructs developing a standardised approach. Therefore, we propose a new guideline for reporting measurement protocols, which covers the 1) equipment and rater, 2) measurement setup, including positioning of the subject, sensor and electrodes, 3) electrical stimulation, including initial stimulation amplitude, increment, and endpoint, and 4) data analysis, including selection criteria and number of analysed signals and a definition of derived parameters.
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Affiliation(s)
- G Langen
- Department of Sports Medicine and Performance Physiology, Goethe University Frankfurt, Frankfurt, Germany; Department of Strength Power and Technical Sports, Institute for Applied Training Science, Leipzig, Germany.
| | - I Sandau
- Department of Strength Power and Technical Sports, Institute for Applied Training Science, Leipzig, Germany
| | - O Ueberschär
- Department of Engineering and Industrial Design, Magdeburg-Stendal University of Applied Sciences, Magdeburg, Germany; Department of Biomechanics, Institute for Applied Training Science, Leipzig, Germany
| | - K Nosaka
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - M Behringer
- Department of Sports Medicine and Performance Physiology, Goethe University Frankfurt, Frankfurt, Germany
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13
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Chen W, Zhang B, Liang T, Tong Z. BUILDING A PROFILE OF SPECIFIC FITNESS INDICES FOR MALE TEENAGE CHINESE SPRINTERS. REV BRAS MED ESPORTE 2022. [DOI: 10.1590/1517-8692202228042021_0166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT Objectives: This study aimed to construct a profile of specific fitness indices for male teenage sprinters on the Chinese National Team to provide sprinting fitness assessments for teenage training. Material and Methods: 229 male teenage sprinters at the same level were recruited to participate in this test for the indices. The t- and Kruskal-Wallis tests were conducted for the first selection of fitness indices. In the second selection, principal components analysis was applied to select common factors with greater characteristic values. The fitness indices chosen were height, leg length, measurement B (ankle circumference/heel length×100%) and measurement A (thigh circumference/leg length×100%), hemoglobin, 60m sprint time, 100m sprint time, countermovement jump (CMJ), maximum countermovement jump velocity, CMJ flight time, CMJ maximum force, and CMJ force. Results: Thirteen indices were chosen for the specific fitness of male teenage Chinese male sprinters with 3 general categories and 9 subcategories. The weight of each fitness index was confirmed and used to construct a standard fitness assessment scale. Conclusion: Anthropometric indices indicate the athlete’s innate limits in the structure of the sprinting motion. Physiological indices indicate the athlete’s potential to expend energy and recover in a short time. Motor indices indicate the athlete’s maximum sprinting ability, lower limb reaction strength, power, and maximum strength. Level of evidence II, Diagnostic studies - Investigation of a diagnostic test.
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Affiliation(s)
- Wenjia Chen
- School of PE at Mining and Technology, China
| | | | | | - Zehao Tong
- School of PE at Mining and Technology, China
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14
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Uchida M, Suga T, Terada M, Isaka T. A pilot study: the relationship between salivary MCP-1 and IgA, and exercise performance in long-distance runners and sprinters. BMC Res Notes 2022; 15:118. [PMID: 35346356 PMCID: PMC8962004 DOI: 10.1186/s13104-022-05989-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 03/01/2022] [Indexed: 12/05/2022] Open
Abstract
Objective It remains unclear that the relationship between sprint and/or endurance performance and salivary immunological factors and stress hormones in athletes. The aim of this study was to investigate if salivary immunological factors and stress hormones are related to sprint and endurance performance in sprinters and long-distance runners. Fourteen male sprinters provided 100-m record and 22 male long-distance runners provided 5000-m record. Salivary IgA, MCP-1, interleukin-8, and cortisol levels in sprinters and long-distance runners were measured by ELISA assay. Results No significant differences were found in all salivary parameters between sprinters and long-distance runners. In long-distance runners, the salivary IgA and MCP-1 concentrations and secretory rate significantly correlated with their personal best 5000-m times (r = 0.534, P = 0.011; r = 0.567, P = 0.006; r = 0.452, P = 0.035, respectively). In sprinters, the salivary IgA concentration, MCP-1 concentration, and MCP-1 secretory rate did not correlate with personal best 100-m sprint times (r = − 0.260, P = 0.369; r = 0.128, P = 0.663; r = 0.122, P = 0.677, respectively). Therefore, the present study is the first to determine that immunological factors such as IgA and MCP1 may be related to endurance performance in long-distance runners.
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Affiliation(s)
- Masataka Uchida
- Ritsumeikan-Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan.
| | - Tadashi Suga
- Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Masafumi Terada
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Tadao Isaka
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
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15
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Ojeda-Aravena A, Herrera-Valenzuela T, Valdés-Badilla P, Azócar-Gallardo J, Campos-Uribe V, García-García JM. Relationship between explosive strength characteristics with change of direction speed in junior and cadet karate athletes. ISOKINET EXERC SCI 2022. [DOI: 10.3233/ies-210114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND: Explosive strength and change of direction speed (CODS) are relevant physical abilities in karate. OBJECTIVE: To examine the relationship between the characteristics of explosive strength and the 5-m linear sprint (5M) with CODS performance and ii) to examine the influential characteristics of explosive strength on CODS performance. METHODS: Eighteen cadet and junior karate athletes, eight females and ten males were evaluated. The physical abilities assessments included: squat jump (SJ), countermovement jump (CMJ), 5M and CODS. Also, pre-stretch percentage increase (PSA), eccentric utilization index (EUR) reactive strength index (RSI) were calculated. RESULTS: Superior performance (p< 0.05) was documented in SJ, CMJ and CODS in male vs. female. Also, significant correlations between CODS with SJ and CMJ (r=-0.70 to -0.80; R2=-0.51 to -0.73; p< 0.05, respectively) and correlations (r=-0.14 to -0.22; R2= 0.01 to 0.04; p> 0.05) between CODS with RSI, EUR and PSA. Multiple regression model documented that only SJ significantly influenced CODS performance in male (R2= 60%; p= 0.009) and female (R2= 71%; p= 0.001). CONCLUSION: CODS correlate with SJ and CMJ. In particular, SJ influence CODS independently of gender.
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Affiliation(s)
- Alex Ojeda-Aravena
- Department of Physical Activity Sciences, Universidad de Los Lagos, Osorno, Chile
- Faculty of Sport Sciences, Sports Training Laboratory, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Tomás Herrera-Valenzuela
- School of Sports and Physical Activity Sciences, Faculty of Health, Universidad Santo Tomás, Santiago, Chile
- School of Physical Activity, Sport and Health Sciences, Universidad de Santiago de Chile, Santiago, Chile
| | - Pablo Valdés-Badilla
- Department of Physical Activity Sciences, Faculty of Education Sciences, Universidad Católica del Maule, Talca, Chile
| | - Jairo Azócar-Gallardo
- Laboratory of Human Performance, Life and Wellness Quality Research Group, Department of Physical Activity Sciences, University of Los Lagos, Osorno, Chile
- Department of Physical Activity Sciences, University of Los Lagos, Puerto Montt, Chile
| | - Victor Campos-Uribe
- Programa de Vida Saludable, Actividad Física y Deporte, Undergraduate Studies Universidad de Talca Campus Curicó, Curicó, Chile
| | - José Manuel García-García
- Faculty of Sport Sciences, Sports Training Laboratory, Universidad de Castilla-La Mancha, Toledo, Spain
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16
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Lázari E, Moraes AMD, Alcântara RAD, Oliveira RLD, Gazzaneo RM. Correlation between body composition data obtained by DXA and skinfold predictive protocols in sprinters. REVISTA BRASILEIRA DE CINEANTROPOMETRIA E DESEMPENHO HUMANO 2022. [DOI: 10.1590/1980-0037.2022v24e83828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Abstract The aim of this study was to describe the correlation between body composition data obtained through DXA and through skinfolds strategy, with some of their respective formulas, in sprinters. The sample consisted of 15 male sprinters (23.81 years ± 3.11; 70.06 Kg ± 4.38; and 179.13 CM ± 5.16) all high performance runners of speed and barriers events (100m, 200m, 400m, 110m with barriers and 400m with barriers). The athletes were submitted to DXA evaluation procedure and to skinfolds collection (triceps, biceps, subscapular, supra iliac, abdominal, medial thigh and calf) and the results were calculated through four distinct equations: Slaughter, Faulkner, Lázari and Boileau. The respective DXA correlations (0.60; 0.81; 0.23 and 0.48) and the equations predicted by skinfold strategy were calculated using Pearson correlation. Among the equations used, Faulkner's was the one presenting highest correlation value when compared to DXA protocol, although all of them aimed to estimate values for BF%.
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17
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The Optimum Power Load: A Simple and Powerful Tool for Testing and Training. Int J Sports Physiol Perform 2021; 17:151-159. [PMID: 34942592 DOI: 10.1123/ijspp.2021-0288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/18/2021] [Accepted: 11/28/2021] [Indexed: 11/18/2022]
Abstract
PURPOSE The optimal power load is defined as the load that maximizes power output in a given exercise. This load can be determined through the use of various instruments, under different testing protocols. Specifically, the "optimum power load" (OPL) is derived from the load-velocity relationship, using only bar force and bar velocity in the power computation. The OPL is easily assessed using a simple incremental testing protocol, based on relative percentages of body mass. To date, several studies have examined the associations between the OPL and different sport-specific measures, as well as its acute and chronic effects on athletic performance. The aim of this brief review is to present and summarize the current evidence regarding the OPL, highlighting the main lines of research on this topic and discussing the potential applications of this novel approach for testing and training. CONCLUSIONS The validity and simplicity of OPL-based schemes provide strong support for their use as an alternative to more traditional strength-power training strategies. The OPL method can be effectively used by coaches and sport scientists in different sports and populations, with different purposes and configurations.
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18
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Ojeda-Aravena A, Herrera-Valenzuela T, Valdés-Badilla P, Martín EBS, Zapata-Bastías J, Aedo-Muñoz E, García-García JM. Interrelationship between specific high-intensity intermittent efforts ability with aerobic capacity and slow stretch-shortening cycle utilization in taekwondo athletes. ISOKINET EXERC SCI 2021. [DOI: 10.3233/ies-210210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: Repeat high-intensity intermittent efforts is a taekwondo-specific ability but the influence of aerobic capacity and dynamic strength characteristics on this ability has received relatively little attention in the literature. OBJECTIVE: To examine the relationship between specific high-intensity intermittent efforts with aerobic capacity and slow stretch-shortening cycle utilization in taekwondo athletes. METHODS: Nineteen taekwondo male athletes were assessed by squat jump (SJ), countermovement jump (CMJ), 20-meter shuttle run (20MSR), and frequency speed of kick test multiple (FSKTMULT). From the FSKTMULT, total kicks and kick decrement index [KDI] were calculated. Additionally, from both jump tests, the slow stretch-shortening cycle utilization (Slow SSC Utilization) was determined from the eccentric utilization ratio [EUR], pre-stretch augmentation [PSA], and reactive strength index [RSI]. RESULTS: There were positive and significant correlations between total kicks with 20MSR (r= 0.85; p= 0.00) and SJ (r= 0.66; p< 0.05). The multiple regression model demonstrated that total kicks where significantly influenced by 20MSR (R2= 71%; p= 0.00). Additionally, only EUR and RSI explained total kicks performance to a greater proportion (R2= 76%). CONCLUSIONS: The FSKTMULT total kicks performance is positively correlated and influenced by aerobic capacity and slow SSC utilization.
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Affiliation(s)
- Alex Ojeda-Aravena
- Department of Physical Activity Sciences, Universidad de Los Lagos, Osorno, Chile
- Facultad de Ciencias del Deporte, Universidad de Castilla-La Mancha, Toledo, España
| | - Tomás Herrera-Valenzuela
- Escuela de Ciencias del Deporte y la Actividad Física, Facultad de Salud, Universidad Santo Tomás (UST), Chile
- Escuela de Ciencias de la Actividad Física, el Deporte y la Salud, Universidad de Santiago de Chile (USACH), Chile
| | - Pablo Valdés-Badilla
- Department of Physical Activity Sciences, Faculty of Education Sciences, Universidad Católica del Maule, Talca, Chile
- Carrera de Entrenador Deportivo, Escuela de Educación, Universidad Viña del Mar, Chile
| | - Eduardo Baez-San Martín
- Carrera de Entrenador Deportivo, Escuela de Educación, Universidad Viña del Mar, Chile
- Departamento de Deportes y Recreación, Facultad de Ciencias de la Actividad Física, Universidad de Playa Ancha, Valparaíso, Chile
| | - José Zapata-Bastías
- Carrera de Entrenador Deportivo, Escuela de Educación, Universidad Viña del Mar, Chile
| | - Esteban Aedo-Muñoz
- Escuela de Ciencias de la Actividad Física, el Deporte y la Salud, Universidad de Santiago de Chile (USACH), Chile
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19
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Muscle Contractile Properties Measured at Submaximal Electrical Amplitudes and Not at Supramaximal Amplitudes Are Associated with Repeated Sprint Performance and Fatigue Markers. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182111689. [PMID: 34770202 PMCID: PMC8582878 DOI: 10.3390/ijerph182111689] [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: 10/03/2021] [Revised: 11/03/2021] [Accepted: 11/05/2021] [Indexed: 11/25/2022]
Abstract
Background: The present study analyzes the associations between the muscle contractile properties (MCP) measured at different neuromuscular electrical stimulation amplitudes (NMESa) and the performance or transient fatigue after a bout of repeated sprints. Methods: Seventeen physically active male subjects performed six repeated sprints of 30 m with 30 s of passive recovery. Capillary blood creatine kinase (CK) concentration, knee extension or flexion isometric peak torque, tensiomyography, and repeated sprint performance were assessed. Results: Muscle displacement and contraction time were different in relation to the NMESa used in the rectus femoris and biceps femoris muscles. At rest, significant (p < 0.05) associations were found between muscle displacement and the loss of time in the repeated sprints (sprint performance) at 20 or 40 mA in the rectus femoris. At post +24 h or +48 h, the highest significant associations were found between the muscle displacement or the contraction time and CK or peak torques also at submaximal amplitudes (20 mA). The NMESa which elicits the peak muscle displacement showed lack of practical significance. Conclusion: Although MCP are typically assessed in tensiomyography using the NMESa that elicit peak muscle displacement, a submaximal NMESa may have a higher potential practical application to assess neuromuscular fatigue in response to repeated sprints.
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20
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Jarvis P, Turner A, Read P, Bishop C. Reactive Strength Index and its Associations with Measures of Physical and Sports Performance: A Systematic Review with Meta-Analysis. Sports Med 2021; 52:301-330. [PMID: 34606061 DOI: 10.1007/s40279-021-01566-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2021] [Indexed: 01/24/2023]
Abstract
BACKGROUND Reactive strength index (RSI) is used frequently in the testing and monitoring of athletes. Associations with sports performance measures may vary dependent on the task but a literature synthesis has not been performed. OBJECTIVES The aim of this meta-analysis was to examine associations between RSI measured during rebound jumping tasks and measures of strength, linear and change of direction speed, and endurance performance. METHODS A systematic literature search with meta-analysis was conducted using databases PubMed, SPORTDiscus, Web of Science, and Ovid. Inclusion criteria required studies to (1) examine the relationship between RSI and an independent measure of physical or sporting performance for at least one variable; and (2) provide rebound test instructions to minimise ground contact time and maximise displacement of the jump. Methodological quality was assessed using a modified version of the Downs and Black Quality Index tool. Heterogeneity was examined via the Q statistic and I2. Pooled effect sizes were calculated using a random-effects model, with Egger's regression test used to assess small study bias (inclusive of publication bias). RESULTS Of the 1320 citations reviewed, a total of 32 studies were included in this meta-analysis. RSI was significantly and moderately associated with strength (isometric: r = 0.356 [95% CI 0.209-0.504]; isotonic: r = 0.365 [0.075-0.654]; pooled strength measures: r = 0.339 [0.209-0.469]) and endurance performance (r = 0.401 [0.173-0.629]). Significant moderate and negative associations were indicated for acceleration (r = - 0.426 [- 0.562 to - 0.290]), top speed (r = - 0.326 [- 0.502 to - 0.151]), and significant large negative associations were noted for change of direction speed (r = - 0.565 [- 0.726 to - 0.404]). Heterogeneity was trivial to moderate across all measures (I2 = 0-66%), and significant for isotonic strength and change of direction speed (p < 0.1). Evidence of small study bias was apparent for both acceleration and change of direction speed (p < 0.05). CONCLUSIONS We identified primarily moderate associations between RSI and independent measures of physical and sporting performance, and the strength of these relationships varied based on the task and physical quality assessed. The findings from this meta-analysis can help practitioners to develop more targeted testing and monitoring processes. Future research may wish to examine if associations are stronger in tasks that display greater specificity.
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Affiliation(s)
- Paul Jarvis
- Faculty of Science and Technology, London Sport Institute, Middlesex University, London, UK.
| | - Anthony Turner
- Faculty of Science and Technology, London Sport Institute, Middlesex University, London, UK
| | - Paul Read
- Institute of Sport, Exercise and Health, London, UK.,Division of Surgery and Interventional Science, University College London, London, UK.,School of Sport and Exercise, University of Gloucestershire, Gloucester, UK
| | - Chris Bishop
- Faculty of Science and Technology, London Sport Institute, Middlesex University, London, UK
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21
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Abstract
ABSTRACT Healy, R, Kenny, IC, and Harrison, AJ. Resistance training practices of sprint coaches. J Strength Cond Res 35(7): 1939-1948, 2021-This study describes the results of a survey of resistance training practices of sprint coaches. This study investigated why sprint coaches prescribe resistance training to their athletes, what exercises they select, and what factors are involved with their selection. Forty-one of 73 (56%) sprint coaches with mean ± SD coaching experience of 8.4 ± 6.4 years were included in this study. Coaches completed an online questionnaire consisting of 5 sections: (a) informed consent, (b) coach background information, (c) coach education and qualifications, (d) coaches' views on resistance training, and (e) exercise selection and preference. The results showed that coaches prescribe resistance training to their sprint athletes to develop strength and power, which they believe will transfer to sprint performance. Coaches prescribed a wide variety of traditional, ballistic, and plyometric exercises, with the hurdle jump found to be the most widely prescribed exercise (93% of coaches surveyed). Coaches selected exercises for a variety of reasons; however, the 3 most prominent reasons were: (a) performance adaptations; (b) practicality; and (c) the targeting of muscles/muscle groups. Coaches prioritized exercises that specifically developed strength, power, and reactive strength for their sprint athletes. This research can be used to develop educational resources for sprint coaches who wish to use resistance training with their athletes. In addition, sprint coaches can use the data presented to expand their current exercise repertoire and resistance training practices.
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Affiliation(s)
- Robin Healy
- Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland; and.,Health Research Institute, University of Limerick, Limerick, Ireland
| | - Ian C Kenny
- Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland; and.,Health Research Institute, University of Limerick, Limerick, Ireland
| | - Andrew J Harrison
- Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland; and.,Health Research Institute, University of Limerick, Limerick, Ireland
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22
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Herring CH, Goldstein ER, Fukuda DH. Use of Tensiomyography in Evaluating Sex-Based Differences in Resistance-Trained Individuals After Plyometric and Isometric Midthigh Pull Postactivation Potentiation Protocols. J Strength Cond Res 2021; 35:1527-1534. [PMID: 34027919 DOI: 10.1519/jsc.0000000000004033] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Herring, CH, Goldstein, ER, and Fukuda, DH. Use of tensiomyography in evaluating sex-based differences in resistance-trained individuals after plyometric and isometric midthigh pull postactivation potentiation protocols. J Strength Cond Res 35(6): 1527-1534, 2021-The purposes of this study were to determine if there are sex-based differences in muscular contractile properties as measured by tensiomyography (TMG) and to determine if plyometrics or the isometric midthigh pull are effective methods of eliciting postactivation potentiation (PAP). Thirty strong, resistance-trained men (n = 15) and women (n = 15) underwent 3 testing days consisting of a PAP or control protocol, and pre-TMG and post-TMG and performance testing. Contractile properties from TMG were assessed in the gastrocnemius medial head (GMH), gluteus maximus (GM), rectus femoris (RF), and biceps femoris (BF). Performance testing included countermovement jumps (CMJs) and 30-m sprints. A time × sex interaction was found for GM delay time with women primarily influencing changes (mean difference = 2.74 ms) rather than men (mean difference = 1.32 ms). Main effects for time revealed an increase in GMH velocity of contraction (+0.004 mm·ms-1) and reductions in GM contraction time (-2.85 ms), GM delay time (-2.03 ms), RF delay time (-0.65 ms), CMJs (-2.74 cm), and 30-m time (0.05 seconds). Main effects for sex revealed greater values in women for GM contraction time (+15.50 ms), GM delay time (+6.65 ms), RF delay time (+2.26 ms), BF contraction time (+8.44 ms), BF delay time (+4.07 ms), BF maximal displacement (+2.27 mm), and 30-m time (+0.67 seconds), and lower values in women for GM velocity of contraction (-0.039 mm·ms-1) and CMJs (-13.46 cm).These findings may help practitioners optimize performance through enhanced assessments for injury risk, targeting specific muscles for training, and by selecting proper CAs and rest periods when using PAP.
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Affiliation(s)
- Chad H Herring
- Physiology of Work and Exercise Response (POWER) Laboratory, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida; and
- Division of Kinesiology, School of Kinesiology and Physical Therapy, University of Central Florida, Orlando, Florida
| | - Erica R Goldstein
- Physiology of Work and Exercise Response (POWER) Laboratory, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida; and
- Division of Kinesiology, School of Kinesiology and Physical Therapy, University of Central Florida, Orlando, Florida
| | - David H Fukuda
- Physiology of Work and Exercise Response (POWER) Laboratory, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida; and
- Division of Kinesiology, School of Kinesiology and Physical Therapy, University of Central Florida, Orlando, Florida
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23
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Assessment of the Multi-Location External Workload Profile in the Most Common Movements in Basketball. SENSORS 2021; 21:s21103441. [PMID: 34063340 PMCID: PMC8156149 DOI: 10.3390/s21103441] [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: 03/23/2021] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 01/30/2023]
Abstract
The present study analyzed the multi-location external workload profile in basketball players using a previously validated test battery and compared the demands among anatomical locations. A basketball team comprising 13 semi-professional male players was evaluated in five tests (abilities/skills/tests): (a) aerobic, linear movement, 30-15 IFT; (b) lactic anaerobic, acceleration and deceleration, 16.25 m RSA (c) alactic anaerobic, curvilinear movement, 6.75 m arc (d) elastic, jump, Abalakov test (e) physical-conditioning, small-sided game, 10' 3 vs.3 10 × 15 m. PlayerLoadRT was evaluated at six anatomical locations simultaneously (interscapular line, lumbar region, knees and ankles) by six WIMU PROTM inertial devices attached to the player using an ad hoc integral suit. Statistical analysis was composed of an ANOVA of repeated measures and partial eta squared effect sizes. Significant differences among anatomical locations were found in all tests with higher values in the location nearer to ground contact (p < 0.01). However, differences between lower limb locations were only found in curvilinear movements, with a higher workload in the outside leg (p < 0.01). Additionally, high between-subject variability was found in team players, especially at lower limb locations. In conclusion, multi-location evaluation in sports movements will make it possible to establish an individual external workload profile and design specific strategies for training and injury prevention programs.
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The Protective Effect of Neuromuscular Training on the Medial Tibial Stress Syndrome in Youth Female Track-and-Field Athletes: A Clinical Trial and Cohort Study. J Sport Rehabil 2021; 30:1019-1027. [PMID: 33883301 DOI: 10.1123/jsr.2020-0376] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/03/2021] [Accepted: 02/05/2021] [Indexed: 11/18/2022]
Abstract
CONTEXT Few reports have analyzed the effects of neuromuscular (NM) training programs on the injury incidence among youth female track-and-field athletes. OBJECTIVE To determine the effects of NM training on reducing lower limb injury incidence and to establish its effects on countermovement jump performance, balance, 30-m sprint, and joint position sense in youth female track-and-field athletes. DESIGN Single-blind, randomized controlled clinical trial. SETTING Sports research laboratory. PARTICIPANTS Twenty-two female athletes were allocated into 2 groups: Conventional (CONV) training (n = 11; age = 15.3 [2.1] y) and NM training (n = 11; age = 15.0 [2.7] y). INTERVENTIONS Interventions were performed during the preseason of 6 weeks. The CONV training included anaerobic, strength, and aerobic training. The NM training consisted of a multicomponent program that integrated jumps, landings, and running with strength, endurance, agility, balance, and CORE training. MAIN OUTCOME MEASURES A follow-up of the cohorts was carried out through the evaluation of lower limb injuries (main outcome) during a regular season (weeks 7-18). Secondary outcomes were measured before and after the intervention: Y-balance test, active joint repositioning, ground reaction force, and countermovement jump height. RESULTS The injury incidence rate was 17.89 injuries per 1000 hours athlete-exposure in CONV training, and 6.58 in NM training (relative risk = 0.38; 95% confidence interval, 0.18 to 0.82; P = .044). Particularly, the medial tibial stress syndrome incidence rate was 5.96 injuries per 1000 hours athlete-exposure in CONV training and 0.82 in NM training (relative risk = 0.17; 95% confidence interval, 0.02 to 1.12; P = .012). In addition, a significant training × time interaction was noted, favoring improvements in 30-m sprint and countermovement jump height after NM. CONCLUSION The NM training may improve youth female athlete's physical fitness and reduce their injury relative risk of medial tibial stress syndrome injury.
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Sañudo B, de Hoyo M, Haff GG, Muñoz-López A. Influence of Strength Level on the Acute Post-Activation Performance Enhancement Following Flywheel and Free Weight Resistance Training. SENSORS 2020; 20:s20247156. [PMID: 33327405 PMCID: PMC7764837 DOI: 10.3390/s20247156] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 11/16/2022]
Abstract
This study aimed to compare the post-activation potentiation performance enhancement (PAPE) response to the acute inertial flywheel (FW) and free weight resistance training (TRA) on subsequent countermovement jump (CMJ) and sprint performance (10 m sprint). This study used a randomized crossover design including twenty-eight healthy males that were divided into strong (relative one-repetition maximum (1RM) back squat > 2.0 × body mass) and weak (relative 1RM back squat < 2.0 × body mass) groups. All participants performed the following: (a) three reps at 90% of their 1RM back squat (TRA) and (b) three reps on an inertial FW (plus one repetition to initiate flywheel movement) with an intensity that generated a mean propulsive velocity equal to that achieved with 90% of the 1RM back squat. Before and after the conditioning activity, participants performed two CMJs and two 10 m sprints. Within-group analyses showed significantly greater CMJ (d > 0.9, p < 0.001) and sprint performance (d > 0.5, p < 0.05) in the FW and the TRA group. Between-group analysis showed that sprint changes were significantly greater in the FW-strong group when compared with the TRA (F1,18 = 5.11, p = 0.036, η2p = 0.221-large) group. These results suggest that using a squat activation protocol on a FW may lead to an acute positive effect on jump and sprint performance, especially in stronger individuals.
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Affiliation(s)
- Borja Sañudo
- Department of Physical Education and Sport, University of Seville, 41013 Seville, Spain; (B.S.); (M.d.H.)
| | - Moisés de Hoyo
- Department of Physical Education and Sport, University of Seville, 41013 Seville, Spain; (B.S.); (M.d.H.)
| | - G Gregory Haff
- Centre for Exercise and Sports Science Research, Edith Cowan University, Joondalup, WA 6065, Australia;
| | - Alejandro Muñoz-López
- Departamento de Motricidad Humana y Rendimiento Deportivo, Education Sciences School, University of Seville, 41013 Seville, Spain
- Correspondence: ; Tel.: +34-699-66-14-47
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Pereira LA, Freitas TT, Pivetti B, Alcaraz PE, Jeffreys I, Loturco I. Short-Term Detraining Does Not Impair Strength, Speed, and Power Performance in Elite Young Soccer Players. Sports (Basel) 2020; 8:sports8110141. [PMID: 33113840 PMCID: PMC7692758 DOI: 10.3390/sports8110141] [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: 09/23/2020] [Revised: 10/13/2020] [Accepted: 10/19/2020] [Indexed: 12/14/2022] Open
Abstract
This study aimed to examine the effects of short-term detraining on the strength, speed, and jump capacities of under-20 soccer players. Twenty-four elite under-20 soccer players from the same professional club were assessed pre and post 26 days of detraining. The measurements were performed in the following order: countermovement jump (CMJ); 10 m linear sprint velocity; and one-repetition maximum test (1RM) in the horizontal leg-press exercise. To analyze the differences between pre- and post-tests, a paired T-test was applied. The significance level was set as p < 0.05. Soccer players exhibited a significant increase in CMJ performance (p = 0.02) and no significant differences in 10 m sprint velocity and 1RM leg-press were found after the short-term training cessation (p = 0.61; p = 0.55, respectively). We demonstrated that a short-term detraining period was capable of promoting a significant increase in the vertical jump height without inducing negative effects on the strength and speed capabilities of elite under-20 soccer players. Practitioners and sport scientists should be aware of these findings to program more effective training strategies at the beginning of the subsequent training cycle.
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Affiliation(s)
- Lucas A. Pereira
- NAR-Nucleus of High Performance in Sport, São Paulo 04753060, Brazil; (L.A.P.); (T.T.F.)
- Department of Human Movement Sciences, Federal University of São Paulo, São Paulo 11015020, Brazil
| | - Tomás T. Freitas
- NAR-Nucleus of High Performance in Sport, São Paulo 04753060, Brazil; (L.A.P.); (T.T.F.)
- Department of Human Movement Sciences, Federal University of São Paulo, São Paulo 11015020, Brazil
- UCAM Research Center for High Performance Sport, Catholic University of Murcia, 30107 Murcia, Spain;
| | | | - Pedro E. Alcaraz
- UCAM Research Center for High Performance Sport, Catholic University of Murcia, 30107 Murcia, Spain;
- Faculty of Sport Sciences, Catholic University of Murcia, 30107 Murcia, Spain
| | - Ian Jeffreys
- University of South Wales, Pontypridd CF37 1DL, UK;
| | - Irineu Loturco
- NAR-Nucleus of High Performance in Sport, São Paulo 04753060, Brazil; (L.A.P.); (T.T.F.)
- Department of Human Movement Sciences, Federal University of São Paulo, São Paulo 11015020, Brazil
- University of South Wales, Pontypridd CF37 1DL, UK;
- Correspondence:
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Trinschek J, Zieliński J, Kusy K. Maximal Oxygen Uptake Adjusted for Skeletal Muscle Mass in Competitive Speed-Power and Endurance Male Athletes: Changes in a One-Year Training Cycle. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17176226. [PMID: 32867179 PMCID: PMC7504314 DOI: 10.3390/ijerph17176226] [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: 07/31/2020] [Revised: 08/24/2020] [Accepted: 08/25/2020] [Indexed: 11/16/2022]
Abstract
We compared the changes in maximum oxygen uptake (V·O2max) calculated per skeletal muscle mass (SMM) with conventional V·O2max measures in a 1-year training cycle. We hypothesized that the pattern of changes would differ between SMM-adjusted and absolute or weight-adjusted values, and the differences between groups of distinct training specialization and status will depend on the measure used. Twelve sprinters (24.7 ± 3.3 years), 10 endurance runners (25.3 ± 5.3 years), and 10 recreationally trained controls (29 ± 4.5 years) performed a treadmill test until exhaustion to determine V·O2max. Their SMM was estimated based on the dual X-ray absorptiometry method and a regression equation. The significance of differences was assessed using analysis of variance (p ≤ 0.05). The pattern of the longitudinal change was not different between V·O2max/SMM and standard measures. Also, the significance of differences between sprinters and endurance athletes remained similar regardless of the V·O2max measure. Sprinters and controls had similar absolute (~4.3 L·min−1) and total weight-adjusted (~52 vs. ~56 mL·min−1·kg) V·O2max, but they significantly differed in SMM-adjusted V·O2max (~110 vs. ~130 mL·min−1·kg SMM−1). In summary, SMM-adjusted V·O2max is not more useful than standard measures to track longitudinal changes in competitive athletes. However, it allows to better distinguish between groups or individuals differing in training status. The results of our study are limited to male athletes.
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Boullosa D, Abad CCC, Reis VP, Fernandes V, Castilho C, Candido L, Zagatto AM, Pereira LA, Loturco I. Effects of Drop Jumps on 1000-m Performance Time and Pacing in Elite Male and Female Endurance Runners. Int J Sports Physiol Perform 2020; 15:1043-1046. [PMID: 32176865 DOI: 10.1123/ijspp.2019-0585] [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: 07/18/2019] [Revised: 09/11/2019] [Accepted: 10/14/2019] [Indexed: 11/18/2022]
Abstract
PURPOSE To evaluate the effect of drop jumps (DJs) on performance time and pacing in a field test (ie, 1000 m) commonly used to evaluate endurance runners and to evaluate running and jumping performance in male and female athletes separately. METHODS Twenty elite endurance runners (male, n = 10, 27.8 [7.0] y, 62.3 [5.2] kg; female, n = 10, 25.9 [5.3] y, 51.7 [4.1] kg) competing in middle- and long-distance events participated in this study. After determination of the box height associated with the best reactive strength index, athletes randomly performed a warm-up with or without the inclusion of 5 DJs with the highest reactive strength index prior to a 1000-m track test. Performance time and pacing (250-m splits) were determined. Countermovement-jump heights at different time points and blood lactate concentration after running tests were also recorded. RESULTS A "possible" faster 1000-m time (162.4 vs 165.3 s) with a "very likely" faster first split (38.8 vs 40.3 s) was observed in male athletes in the DJ condition. In contrast, female athletes showed a "possible" slower running time (186.8 vs 184.8 s) and a "likely" greater blood lactate concentration after the 1000-m test in the DJ condition. Male and female athletes presented greater countermovement-jump performances after warm-up and running tests in both conditions. CONCLUSIONS The inclusion of 5 DJs with the height associated with the best reactive strength index induced a "possible" improvement in 1000-m performance time in elite male endurance runners. The current protocol should be avoided in female athletes.
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Valenzuela PL, McGuigan M, Sánchez-Martínez G, Torrontegi E, Vázquez-Carrión J, Montalvo Z, Abad CCC, Pereira LA, Loturco I. Reference power values for the jump squat exercise in elite athletes: A multicenter study. J Sports Sci 2020; 38:2273-2278. [PMID: 32573360 DOI: 10.1080/02640414.2020.1783150] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The present study aimed to provide reference values for lower-limb muscle power assessed during the incremental jump squat (JS) test in elite athletes (i.e., professional athletes competing at international level). We pooled data from all JS tests performed by elite athletes of different sports in two high-performance centres between 2015 and 2019, and computed reference values (i.e., terciles) for mean power (MP), mean propulsive power (MPP), and peak power (PP). Reference values were obtained from 684 elite athletes (458 male and 226 female) of 16 different sports (boxing, judo, karate, fencing, taekwondo, wrestling, basketball, soccer, futsal, handball, rugby union, badminton, tennis, long distance running, triathlon, and sprinting). Significant differences (p < 0.001) were found between male and female athletes for MP (7.47 ± 1.93 and 6.15 ± 1.68 W·Kg-1, respectively), MPP (10.50 ± 2.75 and 8.63 ± 2.43 W·Kg-1), and PP (23.64 ± 6.12 and 19.35 ± 5.49 W·Kg-1). However, the velocity at which these power measures was attained seemed to be independent of sex (~0.95, 1.00 and 2.00 m·s-1 for mean, mean propulsive, and peak velocity, respectively) and homogeneous across different sport disciplines (coefficient of variation <10%). These data can be used to classify athletes' power capabilities, and the optimum velocity ranges provided here could be useful for training purposes.
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Affiliation(s)
- Pedro L Valenzuela
- Physiology Unit, Systems Biology Department, University of Alcalá , Madrid, Spain.,Department of Sport and Health, Spanish Agency for Health Protection in Sport (AEPSAD) , Madrid, Spain
| | - Michael McGuigan
- Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology , Auckland, New Zealand.,School of Medical and Health Sciences, Edith Cowan University , Perth, Australia
| | | | - Elaia Torrontegi
- Department of Sport and Health, Spanish Agency for Health Protection in Sport (AEPSAD) , Madrid, Spain
| | - Javier Vázquez-Carrión
- Department of Sport and Health, Spanish Agency for Health Protection in Sport (AEPSAD) , Madrid, Spain
| | - Zigor Montalvo
- Department of Sport and Health, Spanish Agency for Health Protection in Sport (AEPSAD) , Madrid, Spain
| | | | - Lucas A Pereira
- NAR - Nucleus of High Performance in Sport , São Paulo, Brazil.,Department of Human Movement Sciences, Federal University of São Paulo , São Paulo, Brazil
| | - Irineu Loturco
- NAR - Nucleus of High Performance in Sport , São Paulo, Brazil.,Department of Human Movement Sciences, Federal University of São Paulo , São Paulo, Brazil.,University of South Wales , Pontypridd, Wales, UK
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30
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Muñoz-López A, De Hoyo M, Nuñez FJ, Sañudo B. Using Tensiomyography to Assess Changes in Knee Muscle Contraction Properties After Concentric and Eccentric Fatiguing Muscle Actions. J Strength Cond Res 2020; 36:935-940. [PMID: 32168176 DOI: 10.1519/jsc.0000000000003562] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Muñoz-López, A, De Hoyo, M, Nuñez, FJ, and Sañudo, B. Using tensiomyography to assess changes in knee muscle contraction properties after concentric and eccentric fatiguing muscle actions. J Strength Cond Res XX(X): 000-000, 2020-The purposes of this study were to analyze the effects of different types of muscle contraction (concentric and eccentric) on the passive muscular contraction properties of knee muscles and how muscle contraction can affect the muscles in different knee functions. In total, 23 active healthy men (age: 24.65 ± 1.95 years, height: 1.78 ± 0.05 m, mass: 75.33 ± 8.37 kg) participated in this study. Muscle soreness, muscle contractile properties assessed with tensiomyography (TMG) (vastus lateralis [VL] and biceps femoris [BF]), and isometric peak torque were tested before and immediately after 32 maximal repetitions of an isokinetic leg extension and flexion exercise at 180° per second. Muscle contractions were randomized to each subject's leg. From the TMG variables, only contraction velocity showed significant interactions in time × muscle × contraction (p = 0.046; partial ηp = 0.19). A greater reduction was observed in the BF (-29.03%) than in the VL (-21.25%). There was a significant decrease in contraction velocity after concentric p < 0.001, d = 1.18) and eccentric (p = 0.007, d = 0.51) exercise for the BF, while for VL, a decrease was only observed after concentric exercise (p = 0.007, d = 0.66). The leg extension exercise showed reductions in the isokinetic peak torque (p < 0.001; partial ηp = 0.83). Isometric peak torque (p < 0.001; partial ηp = 0.80) and muscle soreness (p < 0.001; partial ηp = 0.70) decreased after exercise. In conclusion, muscle mechanical properties were differently affected in relation to the muscle contraction and knee muscles involved, after a fatiguing leg extension isokinetic exercise. Isometric peak torque and muscle soreness were also reduced immediately after exercise. These results are particularly important to understand how TMG parameters are modified depending on the type of contraction.
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Affiliation(s)
| | - Moisés De Hoyo
- Physical Education and Sports, University of Seville, Seville, Spain
| | - Francisco J Nuñez
- Physical Performance and Sports Research, Pablo de Olavide University, Seville, Spain
| | - Borja Sañudo
- Physical Education and Sports, University of Seville, Seville, Spain
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Edouard P, Richardson A, Navarro L, Gremeaux V, Branco P, Junge A. Relation of Team Size and Success With Injuries and Illnesses During Eight International Outdoor Athletics Championships. Front Sports Act Living 2019; 1:8. [PMID: 33344932 PMCID: PMC7739616 DOI: 10.3389/fspor.2019.00008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/15/2019] [Indexed: 11/13/2022] Open
Abstract
Introduction: The number of injuries and illnesses during major athletics championships vary according to sex and discipline. They may also differ between countries (national teams) given the differences in training, medical care, nutrition, lifestyle habits, and in travel to the championships. In addition, injuries and illnesses may influence the performance during the championships. Therefore, the aim was to analyse the differences in the injury and illness occurrence during international outdoor athletics championships with regards to the athlete's country, as well as establishing the potential relationships with the success of the country during the respective championships. Method: The national medical teams and the local organizing committee physicians reported all injuries and illnesses daily on a standardized injury and illness report form during 4 World and 4 European outdoor championships from 2007 to 2018. Results were presented as number of registered athletes, injuries, illnesses and medals (absolute and per 1000 registered athletes), and for countries of different team size. Results: During these 8 championships, a total of 219 different countries participated with a total of 13059 registered athletes who incurred 1315 injuries and 550 illnesses. The number of injuries and illnesses per championships varied between countries. Countries with higher numbers of registered athletes had a higher number of injuries and illnesses, as well as a higher number of medals and gold medals. There were significant positive correlations between number of injuries/illnesses and number of registered athletes, medals, gold medals. Injury and illness numbers per 1,000 registered athletes differed between countries and team sizes. Analyzing country participation grouped according to the number of registered athletes, there were significant negative correlations between injury/illness and medals/gold medals per 1,000 registered athletes. Conclusions: Given the correlation between health problems and country size, we suggest that medical services provision and staff should be adapted to the team size. In groups of different country team sizes, lower number of injuries and illnesses per registered athletes were correlated with higher number of medals and gold medals per registered athletes, which can support that injury and illness prevention should be recognized as a win-win performance-prevention strategy.
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Affiliation(s)
- Pascal Edouard
- Inter-University Laboratory of Human Movement Science (LIBM EA 7424), University of Lyon, University Jean Monnet, Saint Etienne, France.,Sports Medicine Unit, Department of Clinical and Exercise Physiology, Faculty of Medicine, University Hospital of Saint-Etienne, Saint-Etienne, France.,Medical Commission, French Athletics Federation (FFA), Paris, France.,Division de Médecine Physique et Réadaptation, Swiss Olympic Medical Center, Centre de Médecine du Sport, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.,European Athletics Medical & Anti Doping Commission, European Athletics Association (EAA), Lausanne, Switzerland
| | - Andy Richardson
- Institute of Cellular Medicine, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Laurent Navarro
- Mines Saint-Etienne, Univ Lyon, Univ Jean Monnet, INSERM, U 1059 Sainbiose, Centre CIS, Saint-Etienne, France
| | - Vincent Gremeaux
- Division de Médecine Physique et Réadaptation, Swiss Olympic Medical Center, Centre de Médecine du Sport, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.,Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Pedro Branco
- European Athletics Medical & Anti Doping Commission, European Athletics Association (EAA), Lausanne, Switzerland.,Health and Science Commission, International Association of Athletics Federations (IAAF), Monaco, Monaco
| | - Astrid Junge
- Medical School Hamburg, Hamburg, Germany.,Swiss Concussion Center, Schulthess Clinic Zurich, Zurich, Switzerland
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Loturco I, Suchomel T, James LP, Bishop C, Abad CCC, Pereira LA, McGuigan MR. Selective Influences of Maximum Dynamic Strength and Bar-Power Output on Team Sports Performance: A Comprehensive Study of Four Different Disciplines. Front Physiol 2018; 9:1820. [PMID: 30618830 PMCID: PMC6304672 DOI: 10.3389/fphys.2018.01820] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/05/2018] [Indexed: 11/15/2022] Open
Abstract
This study examined the selective influences of one-repetition maximum (1RM) values [assessed in the half-squat (HS)] and bar-power production [assessed in both HS and jump squat (JS) exercises] on the physical performance of male and female team sport athletes from four different sports. Three-hundred and three elite players (31 Olympians) from four different disciplines (47 male soccer players, 58 female soccer players, 28 male handball players, 58 female handball players, 49 male rugby players, and 63 male futsal players) participated in this study. The physical tests were performed over 2 consecutive days for soccer and rugby players, and in 1 day for the remaining athletes. On the first day, rugby and soccer athletes performed squat jumps (SJ), countermovement jumps (CMJ), and HS 1RM. On the second day, they executed HS and JS tests (to assess the maximum bar-power output) and the linear and change-of-direction (COD) speed tests. For the other players, the sequence of the measurements was the same; however, they did not perform the HS exercise. Athletes were separated, using a median split analysis, into two distinct groups, according to their bar-power output in both JS and HS exercises and their performance in HS 1RM. The magnitude-based inferences method was used to examine the differences between "higher" and "lower" performance groups. Overall, the bar-power outputs were better connected to improved acceleration, speed, and jump performance than the 1RM measures. From these findings, it is possible to infer that players able to produce higher bar-power outputs are likely to sprint faster and jump higher. Therefore, coaches involved in team sports are strongly encouraged to use the bar-power method to evaluate the athletic performance of their players.
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Affiliation(s)
- Irineu Loturco
- NAR – Nucleus of High Performance in Sport, São Paulo, Brazil
| | - Timothy Suchomel
- Department of Human Movement Sciences, Carroll University, Waukesha, WI, United States
| | - Lachlan P. James
- La Trobe Sport and Exercise Medicine Research Centre, Department of Rehabilitation, Nutrition and Sport, School of Allied Health, La Trobe University, Melbourne, VIC, Australia
| | - Chris Bishop
- Faculty of Science and Technology, London Sports Institute, Middlesex University, London, United Kingdom
| | | | | | - Michael R. McGuigan
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
- School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia
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Kubo T, Hirayama K, Nakamura N, Higuchi M. Effect of Accommodating Elastic Bands on Mechanical Power Output during Back Squats. Sports (Basel) 2018; 6:E151. [PMID: 30469523 PMCID: PMC6316108 DOI: 10.3390/sports6040151] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 11/13/2018] [Accepted: 11/20/2018] [Indexed: 11/16/2022] Open
Abstract
The aim of this study was to investigate whether accommodating elastic bands with barbell back squats (BSQ) increase muscular force during the deceleration subphase. Ten healthy men (mean ± standard deviation: Age: 23 ± 2 years; height: 170.5 ± 3.7 cm; mass: 66.7 ± 5.4 kg; and BSQ one repetition maximum (RM): 105 ± 23.1 kg; BSQ 1RM/body mass: 1.6 ± 0.3) were recruited for this study. The subjects performed band-resisted parallel BSQ (accommodating elastic bands each sides of barbell) with five band conditions in random order. The duration of the deceleration subphase, mean mechanical power, and the force and velocity during the acceleration and deceleration subphases were calculated. BSQ with elastic bands elicited greater mechanical power output, velocity, and force during the deceleration subphase, in contrast to that elicited with traditional free weight (p < 0.05). BSQ with elastic bands also elicited greater mechanical power output and velocity during the acceleration subphase. However, the force output during the acceleration subphase using an elastic band was lesser than that using a traditional free weight (p < 0.05). This study suggests that BSQ with elastic band elicit greater power output during the acceleration and deceleration subphases.
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Affiliation(s)
- Takafumi Kubo
- Graduate School of Sport Sciences, Waseda University, Tokorozawa, Saitama 359-1192, Japan.
| | - Kuniaki Hirayama
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama 359-1192, Japan.
| | - Nobuhiro Nakamura
- Graduate School of Sport Sciences, Waseda University, Tokorozawa, Saitama 359-1192, Japan.
| | - Mitsuru Higuchi
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama 359-1192, Japan.
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Loturco I, Pereira LA, Kobal R, Cal Abad CC, Fernandes V, Ramirez-Campillo R, Suchomel T. Portable Force Plates: A Viable and Practical Alternative to Rapidly and Accurately Monitor Elite Sprint Performance. Sports (Basel) 2018; 6:E61. [PMID: 30002328 PMCID: PMC6162417 DOI: 10.3390/sports6030061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/04/2018] [Accepted: 07/09/2018] [Indexed: 11/18/2022] Open
Abstract
This study aimed to examine the associations between a series of mechanical variables automatically generated by a portable force plate (PFP) and the actual performance of professional sprinters over a 150 m course. To test these correlations, 12 top-level sprinters performed vertical jumps (squat and countermovement jumps; SJ and CMJ, respectively), a 60 m sprint test, and a 150 m sprint test. Pearson product-moment coefficient of correlation and multiple regression analyses were used to determine the relationships between the sprinting velocities and vertical jump outputs. The SJ parameters were moderately to near perfectly associated with the different sprint distances, and the SJ height presented the highest correlation scores (r = 0.90 with velocities over 10- and 20-m). The correlation coefficients between the CMJ outcomes and sprint results varied between moderate and very large (from 0.38 to 0.88). Finally, the coefficients of determination (R²) ranged from 0.71 to 0.85 for the different multiple regressions involving PFP automatic measures. The PFP can provide practitioners with quick and accurate information regarding competitive athletes. Due to the strong correlations observed, coaches are encouraged to frequently adjust and tailor the training strategies of their sprinters, using practical and timesaving PFP measurements.
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Affiliation(s)
- Irineu Loturco
- Nucleus of High Performance in Sport⁻NAR, Sao Paulo 04753060, Brazil.
| | - Lucas A Pereira
- Nucleus of High Performance in Sport⁻NAR, Sao Paulo 04753060, Brazil.
| | - Ronaldo Kobal
- Nucleus of High Performance in Sport⁻NAR, Sao Paulo 04753060, Brazil.
| | - Cesar C Cal Abad
- Nucleus of High Performance in Sport⁻NAR, Sao Paulo 04753060, Brazil.
| | - Victor Fernandes
- B3 Track & Field Club, Sao Paulo 04753060, Brazil.
- Association of High-Performance Training & Sports Development⁻ADAPT, Sao Paulo 04753060, Brazil.
| | - Rodrigo Ramirez-Campillo
- Research Nucleus in Health, Physical Activity and Sport, Department of Physical Activity Sciences, Universidad of Los Lagos, Osorno 5290000, Chile.
| | - Timothy Suchomel
- Department of Human Movement Sciences, Carroll University, Waukesha, WI 53186, USA.
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Loturco I, Pereira LA, Kobal R, McGuigan MR. Power output in traditional and ballistic bench press in elite athletes: Influence of training background. J Sports Sci 2018; 37:277-284. [PMID: 29983101 DOI: 10.1080/02640414.2018.1496517] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
This study aimed to compare the power production in traditional bench-press (TBP) and ballistic bench-throw (BBT) exercises. Furthermore, we assessed the differences in velocity, force, and power outputs between TBP and BBT. Finally, we tested the differences between the loads used to optimize power (optimum power load; OPL) in both exercises, using three distinct power-variables: mean power (MP), mean propulsive power (MPP), and peak power (PP). Sixty athletes from different sports were divided into two groups, according to their training characteristics: hypertrophy-based trained athletes (HTA), thirty-one athletes performing hypertrophy training programmes for (at least) 12-weeks; and power-based trained athletes (PTA), twenty-nine athletes performing power-oriented training sessions for (at least) 12-weeks. Magnitude-based inferences were used to test for differences between groups. Independent of the variable analyzed (MP, MPP, or PP), the PTA produced greater power values in BBT, whereas the HTA generated higher outputs during TBP. The OPL in the HTA was likely heavier in TBP than in BBT, whereas no differences related to this variable were found in the PTA. Despite the apparent superiority of ballistics to produce power, it seems that in elite athletes, the strength-power training routine might affect the ability to apply high forces at very-high velocities.
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Affiliation(s)
- Irineu Loturco
- a NAR - Nucleus of High Performance in Sport , São Paulo , Brazil
| | - Lucas A Pereira
- a NAR - Nucleus of High Performance in Sport , São Paulo , Brazil
| | - Ronaldo Kobal
- a NAR - Nucleus of High Performance in Sport , São Paulo , Brazil
| | - Michael R McGuigan
- b Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology , Auckland , New Zealand.,c School of Medical and Health Sciences, Edith Cowan University , Perth , Australia
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Loturco I, Kobal R, Kitamura K, Cal Abad CC, Faust B, Almeida L, Pereira LA. Mixed Training Methods: Effects of Combining Resisted Sprints or Plyometrics with Optimum Power Loads on Sprint and Agility Performance in Professional Soccer Players. Front Physiol 2017; 8:1034. [PMID: 29311968 PMCID: PMC5732948 DOI: 10.3389/fphys.2017.01034] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 11/29/2017] [Indexed: 11/24/2022] Open
Abstract
The aim of this study was to compare the effects of two different mixed training programs (optimum power load [OPL] + resisted sprints [RS] and OPL + vertical/horizontal plyometrics [PL]) on neuromuscular performance of elite soccer players during a short-term training preseason. Eighteen male professional soccer players took part in this study. The athletes were pair-matched in two training groups: OPL + RS and OPL + PL. Unloaded and resisted sprinting speeds at 5-, 10-, 20-, and 30-m, change of direction (COD) speed, and performance in the squat jump (SJ), countermovement jump (CMJ), and horizontal jump (HJ) were assessed pre- and post- a 5-week training period. Magnitude based inference with the effect sizes were used for data analysis. A possible increase in the SJ and CMJ heights and a likely increase in the HJ distance were observed in the OPL + PL group. Meaningful improvements were observed in the COD speed test for both training groups comparing pre- and post-measures. In both unloaded and resisted sprints, meaningful decreases were observed in the sprinting times for all distances tested. This study shows that a mixed training approach which comprises exercises and workloads able to produce positive adaptations in different phases of sprinting can be a very effective strategy in professional soccer players. Moreover, the possibility of combining optimum power loads with resisted sprints and plyometrics emerges as a novel and suitable option for coaches and sport scientists, due to the applicability and efficiency of this strength-power training approach.
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Affiliation(s)
- Irineu Loturco
- Nucleus of High Performance in Sport (NAR), São Paulo, Brazil
| | - Ronaldo Kobal
- Nucleus of High Performance in Sport (NAR), São Paulo, Brazil
| | - Katia Kitamura
- Nucleus of High Performance in Sport (NAR), São Paulo, Brazil
| | | | - Bruno Faust
- Grêmio Esportivo Osasco Football Club (GEO), São Paulo, Brazil
| | - Lucas Almeida
- Grêmio Esportivo Osasco Football Club (GEO), São Paulo, Brazil
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Loturco I. Authors' response to letter to the editor: "Bar velocities capable of optimising the muscle power in strength-power exercises" by Loturco, Pereira, Abad, Tabares, Moraes, Kobal, Kitamura & Nakamura (2017). J Sports Sci 2017; 36:1602-1606. [PMID: 29157139 DOI: 10.1080/02640414.2017.1405712] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Our study in the Journal of Sports Sciences was originally designed to test whether the bar-velocity is a precise indicator of the power training intensity (i.e., optimum loads) in different exercises commonly included in athletes' training programs. Furthermore, we presented secondary findings, related to the actual results obtained in our assessments. As a cross-sectional study with clear objectives, we focused on discussing issues and applications pertaining to neuromuscular training interventions, such as: (1) describing the advantages of using bar-velocities to control the power training intensity, (2) defining a range of loads capable of maximizing the power production in certain ballistic and traditional exercises, and (3) revealing the differences between these exercises and the respective implications for training. Fundamentally, we did not produce a mechanistic investigation and were very accurate and consistent in reporting our data, collected under rigorous and well-established experimental conditions. Here we provide our point-by-point comments to the concerns raised in the "Letter to the Editor", along with some theoretical explanations about the secondary findings reported by the authors of the Letter. To better understand the nature and purposes of our experiment, we also present a series of practical examples and review previous investigations involving the "bar-power" approach.
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Affiliation(s)
- Irineu Loturco
- a NAR - Nucleus of High Performance in Sport , São Paulo , Brazil
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Kobal R, Pereira LA, Zanetti V, Ramirez-Campillo R, Loturco I. Effects of Unloaded vs. Loaded Plyometrics on Speed and Power Performance of Elite Young Soccer Players. Front Physiol 2017; 8:742. [PMID: 29018362 PMCID: PMC5623051 DOI: 10.3389/fphys.2017.00742] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 09/12/2017] [Indexed: 11/30/2022] Open
Abstract
The purpose of this study was to investigate the effects of loaded and unloaded plyometric training strategies on speed and power performance of elite young soccer players. Twenty-three under-17 male soccer players (age: 15.9 ± 1.2 years, height: 178.3 ± 8.1 cm, body-mass (BM): 68.1 ± 9.3 kg) from the same club took part in this study. The athletes were pair-matched in two training groups: loaded vertical and horizontal jumps using an haltere type handheld with a load of 8% of the athletes' body mass (LJ; n = 12) and unloaded vertical and horizontal plyometrics (UJ; n = 11). Sprinting speeds at 5-, 10-, and 20-m, mean propulsive power (MPP) relative to the players' BM in the jump squat exercise, and performance in the squat jump (SJ) and countermovement jump (CMJ) were assessed pre- and post-training period. During the experimental period, soccer players performed 12 plyometric training sessions across a 6-week preseason period. Magnitude based inferences and standardized differences were used for statistical analysis. A very likely increase in the vertical jumps was observed for the LJ group (99/01/00 and 98/02/00 for SJ and CMJ, respectively). In the UJ group a likely increase was observed for both vertical jumps (83/16/01 and 90/10/00, for SJ and CMJ, respectively). An almost certainly decrease in the sprinting velocities along the 20-m course were found in the LJ group (00/00/100 for all split distances tested). Meanwhile, in the UJ likely to very likely decreases were observed for all sprinting velocities tested (03/18/79, 01/13/86, and 00/04/96, for velocities in 5-, 10-, and 20-m, respectively). No meaningful differences were observed for the MPP in either training group (11/85/04 and 37/55/08 for LJ and UJ, respectively). In summary, under-17 professional soccer players increased jumping ability after a 6-week preseason training program, using loaded or unloaded jumps. Despite these positive adaptations, both plyometric strategies failed to produce worthwhile improvements in maximal speed and power performances, which is possible related to the interference of concurrent training effects. New training strategies should be developed to ensure adequate balance between power and endurance loads throughout short (and high-volume) soccer preseasons.
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Affiliation(s)
- Ronaldo Kobal
- Nucleus of High Performance in Sport (NAR), São Paulo, Brazil
| | | | | | - Rodrigo Ramirez-Campillo
- Department of Physical Activity Sciences, Research Nucleus in Health, Physical Activity and Sport, University of Los Lagos, Osorno, Chile
| | - Irineu Loturco
- Nucleus of High Performance in Sport (NAR), São Paulo, Brazil
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