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Nasser I, Willardson JM, Monteiro W, Miranda H. Postactivation performance enhancement in the vertical jump using loads above or below the optimum-power load for a jump squat. J Sports Med Phys Fitness 2024; 64:348-354. [PMID: 38093641 DOI: 10.23736/s0022-4707.23.15479-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
BACKGROUND Postactivation performance enhancement (PAPE) is an acute response of increased muscle performance following a conditioning activity (CA), generally prescribed based on the percentage of a one-repetition maximum. However, it is unknown how the PAPE response is affected when the CA is performed near the optimum power zone. The purpose of this study was to examine PAPE using loads that were 20% above or below the optimum-power load (OPL). METHODS Fifteen recreationally trained subjects, with at least one-year resistance training experience participated in this study. First, the OPL for the JS was determined. Then, subjects performed two protocols in a counterbalanced order: 20% above (+20%OPL) or below (-20%OPL). To examine PAPE on performance, the vertical jump was performed prior to and seven times following each jump squat protocol, with a 2-min rest interval between trials. RESULTS The two-way ANOVA revealed main effects for condition (F=4.978; P<0.001) for jump height and jump power (F=2.589; P=0.017), but post-hoc comparisons did not show differences. Between baseline and the best trial following each jump squat protocol, two-way ANOVA did not reveal main effects (F=3.048; P=0.103) or interactions (F=0.304; P=0.590). Paired t-tests did not show significant differences between conditions for relative changes in jump height (P=0.543) or jump power (P=0.233). CONCLUSIONS This study revealed similar results between 20% above or below the OPL on subsequent vertical jump performance.
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Affiliation(s)
- Igor Nasser
- School of Physical Education and Sports, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil -
- Performance, Training, and Physical Exercise Laboratory (LADTEF), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil -
| | - Jeffrey M Willardson
- Health and Human Performance Department, Montana State University Billings, Billings, MT, USA
| | - Walace Monteiro
- Graduate Program in Exercise and Sports Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
- Department of Research and Education, National Institute of Cardiology, Ministry of Health, Rio de Janeiro, Brazil
| | - Humberto Miranda
- School of Physical Education and Sports, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Performance, Training, and Physical Exercise Laboratory (LADTEF), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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2
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Mansfield SK, Peiffer JJ, Galna B, Scott BR. The velocity of resistance exercise does not accurately assess repetitions-in-reserve. Eur J Sport Sci 2023; 23:2357-2367. [PMID: 37552530 DOI: 10.1080/17461391.2023.2235314] [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] [Indexed: 08/09/2023]
Abstract
This study assessed the reliability of mean concentric bar velocity from 3- to 0-repetitions in reserve (RIR) across four sets in different exercises (bench press and prone row) and with different loads (60 and 80% 1-repetition maximum; 1RM). Whether velocity values from set one could be used to predict RIR in subsequent sets was also examined. Twenty recreationally active males performed baseline 1RM testing before two randomised sessions of four sets to failure with 60 or 80% 1RM. A linear position transducer measured mean concentric velocity of repetitions, and the velocity associated with each RIR value up to 0-RIR. For both exercises, velocity decreased between each repetition from 3- to 0-RIR (p ≤ 0.010). Mean concentric velocity of RIR values was not reliable across sets in the bench press (mean intraclass correlation coefficient [ICC] = 0.40, mean coefficient of variation [CV] = 21.3%), despite no significant between-set differences (p = 0.530). Better reliability was noted in the prone row (mean ICC = 0.80, mean CV = 6.1%), but velocity declined by 0.019-0.027 m·s-1 (p = 0.032) between sets. Mean concentric velocity was 0.050-0.058 m·s-1 faster in both exercises with 60% than 80% 1RM with (p < 0.001). At the individual level, the velocity of specific RIR values from set one accurately predicted RIR from 5- to 0-RIR for 30.9% of repetitions in subsequent sets. These findings suggest that velocity of specific RIR values vary across exercises, loads and sets. As velocity-based RIR estimates were not accurate for 69.1% of repetitions, alternative methods to should be considered for autoregulating of resistance exercise in recreationally active individuals.
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Affiliation(s)
- Sean K Mansfield
- Murdoch Applied Sports Science Laboratory, Discipline of Exercise Science, Murdoch University, Perth, Australia
| | - Jeremiah J Peiffer
- Murdoch Applied Sports Science Laboratory, Discipline of Exercise Science, Murdoch University, Perth, Australia
- Centre for Healthy Ageing, Murdoch University, Perth, Australia
| | - Brook Galna
- Centre for Healthy Ageing, Murdoch University, Perth, Australia
- Discipline of Exercise Science, Murdoch University, Perth, Australia
| | - Brendan R Scott
- Murdoch Applied Sports Science Laboratory, Discipline of Exercise Science, Murdoch University, Perth, Australia
- Centre for Healthy Ageing, Murdoch University, Perth, Australia
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3
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Achermann B, Oberhofer K, Ferguson SJ, Lorenzetti SR. Velocity-Based Strength Training: The Validity and Personal Monitoring of Barbell Velocity with the Apple Watch. Sports (Basel) 2023; 11:125. [PMID: 37505612 PMCID: PMC10383699 DOI: 10.3390/sports11070125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/14/2023] [Accepted: 06/21/2023] [Indexed: 07/29/2023] Open
Abstract
Velocity-based training (VBT) is a method to monitor resistance training based on measured kinematics. Often, measurement devices are too expensive for non-professional use. The purpose of this study was to determine the accuracy and precision of the Apple Watch 7 and the Enode Pro device for measuring mean, peak, and propulsive velocity during the free-weighted back squat (in comparison to Vicon as the criterion). Velocity parameters from Vicon optical motion capture and the Apple Watch were derived by processing the motion data in an automated Python workflow. For the mean velocity, the barbell-mounted Apple Watch (r = 0.971-0.979, SEE = 0.049), wrist-worn Apple Watch (r = 0.952-0.965, SEE = 0.064) and barbell-mounted Enode Pro (r = 0.959-0.971, SEE = 0.059) showed an equal level of validity. The barbell-mounted Apple Watch (Vpeak: r = 0.952-0.965, SEE = 0.092; Vprop: r = 0.973-0.981, SEE = 0.05) was found to be the most valid for assessing propulsive and peak lifting velocity. The present results on the validity of the Apple Watch are very promising, and may pave the way for the inclusion of VBT applications in mainstream consumer wearables.
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Affiliation(s)
- Basil Achermann
- Section Performance Sport, Swiss Federal Institute of Sport Magglingen (SFISM), 2532 Magglingen, Switzerland
- Institute for Biomechanics, ETH Zurich, 8092 Zurich, Switzerland
| | - Katja Oberhofer
- Section Performance Sport, Swiss Federal Institute of Sport Magglingen (SFISM), 2532 Magglingen, Switzerland
| | | | - Silvio R Lorenzetti
- Section Performance Sport, Swiss Federal Institute of Sport Magglingen (SFISM), 2532 Magglingen, Switzerland
- Institute for Biomechanics, ETH Zurich, 8092 Zurich, Switzerland
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4
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Mitter B, Zhang L, Bauer P, Baca A, Tschan H. Modeling the Relationship between Load and Repetitions to Failure in Resistance Training: A Bayesian Analysis. Eur J Sport Sci 2022:1-11. [PMID: 35703009 DOI: 10.1080/17461391.2022.2089915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To identify the relationship between load and the number of repetitions performed to momentary failure in the pin press exercise, the present study compared different statistical model types and structures using a Bayesian approach. METHODS Thirty resistance-trained men and women were tested on two separate occasions. During the first visit, participants underwent assessment of their one-repetition maximum (1-RM) in the pin press exercise. On the second visit, they performed sets to momentary failure at 90%, 80% and 70% of their 1-RM in a fixed order during a single session. The relationship between relative load and repetitions performed to failure was fitted using linear regression, exponential regression and the critical load model. Each model was fitted according to the Bayesian framework in two ways: using an across-subjects pooled data structure and using a multilevel structure. Models were compared based on the variance explained (R²) and leave-one-out cross-validation information criterion (LOOIC). RESULTS Multilevel models, which incorporate higher-level commonalities into individual relationships, demonstrated a substantially better fit (R²: 0.97-0.98) and better predictive accuracy compared to generalized pooled-data models (R²: 0.89-0.93). The multilevel 2-parameter exponential regression emerged as the best representation of data in terms of model fit, predictive accuracy and model simplicity. CONCLUSION The relationship between load and repetitions performed to failure follows an individually expressed exponential trend in the pin press exercise. To accurately predict the load that is associated with a certain repetition maximum, the relationship should therefore be modeled on a subject-specific level.
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Affiliation(s)
- Benedikt Mitter
- Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria
| | - Lei Zhang
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
| | - Pascal Bauer
- Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria
| | - Arnold Baca
- Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria
| | - Harald Tschan
- Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria
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5
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Moreno-Villanueva A, Pino-Ortega J, Rico-González M. Validity and reliability of linear position transducers and linear velocity transducers: a systematic review. Sports Biomech 2021:1-30. [PMID: 34726576 DOI: 10.1080/14763141.2021.1988136] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 09/24/2021] [Indexed: 10/19/2022]
Abstract
This systematic review aimed to summarise and analyse the evidence on the reliability and validity of linear tranducers (LTs) in exercises of different nature and different modes of execution. This systematic review was carried out under PRISMA guidelines, and was carried out using three databases (PubMed, Web of Sciences, and Scopus). Of the 351 initially found, 21 were included in the qualitative synthesis. The results reflected that linear position transducers (LPTs) were valid and reliable in monitoring movement velocity in non-plyometric exercises. However, precision and reliability were lower in execution protocols without isometric phase and in the execution of exercises in multiple planes of movement, with greater measurement errors at higher sampling frequencies. On the other hand, linear velocity transducers (LVTs) proved to be valid and reliable in measuring velocity during plyometric and non-plyometric exercises performed on the Smith machine, with less variation in measurement in the latter. Finally, the use of peak values is recommended, since they are less dependent on the technological errors of LTs. Therefore, the performance of non-plyometric exercises, carried out in the Smith machine and with an isometric phase in the execution of the movement, will help to minimise the technological error of the LTs.
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Affiliation(s)
| | - José Pino-Ortega
- Faculty of Sports Sciences, University of Murcia, San Javier, Spain
- Department of Physical Activity and Sport, Faculty of Sport Sciences, BIOVETMED & SPORTSCI Research Group, University of Murcia, Murcia, Spain
| | - Markel Rico-González
- Department of Physical Activity and Sport, Faculty of Sport Sciences, BIOVETMED & SPORTSCI Research Group, University of Murcia, Murcia, Spain
- Department of Physical Education and Sport, University of the Basque Country, UPV/EHU, Vitoria-Gasteiz, Spain
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Fritschi R, Seiler J, Gross M. Validity and Effects of Placement of Velocity-Based Training Devices. Sports (Basel) 2021; 9:sports9090123. [PMID: 34564328 PMCID: PMC8472848 DOI: 10.3390/sports9090123] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 11/16/2022] Open
Abstract
Velocity-based training (VBT) is a resistance training method by which training variables are manipulated based on kinematic outcomes, e.g., barbell velocity. The better precision for monitoring and manipulating training variables ascribed to VBT assumes that velocity is measured and communicated correctly. This study assessed the validity of several mobile and one stationary VBT device for measuring mean and peak concentric barbell velocity over a range of velocities and exercises, including low- and high-velocity, ballistic and non-ballistic, and plyometric and non-plyometric movements, and to quantify the isolated effect of device attachment point on measurement validity. GymAware (r = 0.90-1, standard error of the estimate, SEE = 0.01-0.08 m/s) and Quantum (r = 0.88-1, SEE = 0.01-0.18 m/s) were most valid for mean and peak velocity, with Vmaxpro (r = 0.92-0.99, SEE = 0.02-0.13 m/s) close behind. Push (r = 0.69-0.96, SEE = 0.03-0.17 m/s) and Flex (r = 0.60-0.94, SEE = 0.02-0.19 m/s) showed poorer validity (especially for higher-velocity exercises), although typical errors for mean velocity in exercises other than hang power snatch were acceptable. Effects of device placement were detectable, yet likely small enough (SEE < 0.1 m/s) to be negligible in training settings.
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Affiliation(s)
- Raphael Fritschi
- Department of Medicine, Movement and Sport Science, University of Fribourg, 1700 Fribourg, Switzerland;
| | - Jan Seiler
- Department for Elite Sport, Swiss Federal Institute of Sport Magglingen (SFISM), Hauptstrasse 247, 2532 Magglingen, Switzerland;
| | - Micah Gross
- Department for Elite Sport, Swiss Federal Institute of Sport Magglingen (SFISM), Hauptstrasse 247, 2532 Magglingen, Switzerland;
- Correspondence:
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Pérez-Castilla A, Boullosa D, García-Ramos A. Reliability and Validity of the iLOAD Application for Monitoring the Mean Set Velocity During the Back Squat and Bench Press Exercises Performed Against Different Loads. J Strength Cond Res 2021; 35:S57-S65. [PMID: 33021586 DOI: 10.1519/jsc.0000000000003739] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Pérez-Castilla, A, Boullosa, D, and García-Ramos, A. Reliability and validity of the iLOAD application for monitoring the mean set velocity during the back squat and bench press exercises performed against different loads. J Strength Cond Res 35(2S): S57-S65, 2021-This study aimed to evaluate the reliability and validity of a smartphone application (iLOAD) for the monitoring of mean concentric velocity (MV) during resistance training sets. Twenty males completed 2 identical sessions consisting of one set of 10 repetitions against 4 loads (25, 40, 55, 70% of the one repetition maximum [1RM]) during the back squat and bench press exercises. The MV of the 5 initial repetitions and for the whole set were determined simultaneously with the iLOAD application and a linear velocity transducer (LVT). Two independent researchers operated the iLOAD application during the experimental sessions to evaluate the interrater agreement for the assessment of MV. An acceptable but generally lower reliability was observed for iLOAD (coefficient of variation [CV] range: 5.61-9.79%) compared to the LVT (CV range: 4.51-8.18%) at 25-40-55% of 1RM, whereas the reliability at 75% of 1RM was acceptable for the LVT during the bench press (CV range: 6.37-8.26%), but it was unacceptable for the iLOAD during both exercises (CV range: 11.3-12.8%) and for the LVT during the back squat (CV range: 11.3-17.4%). Small to moderate differences (ES range: 0.24-1.04) and very high to practically perfect correlations (r range: 0.70-0.90) were observed between the iLOAD and the LVT. A very high agreement was observed between both raters for the recording of MV during the back squat and bench press exercises (r ≥ 0.98). Taken together, these results suggest that the iLOAD application can be confidently used to quantify the MV of training sets during the squat and bench press exercises not performed to failure.
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Affiliation(s)
- Alejandro Pérez-Castilla
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Daniel Boullosa
- Integrated Institute of Saúde, Federal University of Mato Grosso do Sul, Campo Grande, Brazil
- Sport and Exercise Science, James Cook University, Townsville, Australia; and
| | - Amador García-Ramos
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
- Department of Sports Sciences and Physical Conditioning, Faculty of Education, Catholic University of the Santísima Concepción, Concepción, Chile
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8
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Weakley J, Morrison M, García-Ramos A, Johnston R, James L, Cole MH. The Validity and Reliability of Commercially Available Resistance Training Monitoring Devices: A Systematic Review. Sports Med 2021; 51:443-502. [PMID: 33475985 PMCID: PMC7900050 DOI: 10.1007/s40279-020-01382-w] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2020] [Indexed: 01/04/2023]
Abstract
Background Monitoring resistance training has a range of unique difficulties due to differences in physical characteristics and capacity between athletes, and the indoor environment in which it often occurs. Traditionally, methods such as volume load have been used, but these have inherent flaws. In recent times, numerous portable and affordable devices have been made available that purport to accurately and reliably measure kinetic and kinematic outputs, potentially offering practitioners a means of measuring resistance training loads with confidence. However, a thorough and systematic review of the literature describing the reliability and validity of these devices has yet to be undertaken, which may lead to uncertainty from practitioners on the utility of these devices. Objective A systematic review of studies that investigate the validity and/or reliability of commercially available devices that quantify kinetic and kinematic outputs during resistance training. Methods Following PRISMA guidelines, a systematic search of SPORTDiscus, Web of Science, and Medline was performed; studies included were (1) original research investigations; (2) full-text articles written in English; (3) published in a peer-reviewed academic journal; and (4) assessed the validity and/or reliability of commercially available portable devices that quantify resistance training exercises. Results A total of 129 studies were retrieved, of which 47 were duplicates. The titles and abstracts of 82 studies were screened and the full text of 40 manuscripts were assessed. A total of 31 studies met the inclusion criteria. Additional 13 studies, identified via reference list assessment, were included. Therefore, a total of 44 studies were included in this review. Conclusion Most of the studies within this review did not utilise a gold-standard criterion measure when assessing validity. This has likely led to under or overreporting of error for certain devices. Furthermore, studies that have quantified intra-device reliability have often failed to distinguish between technological and biological variability which has likely altered the true precision of each device. However, it appears linear transducers which have greater accuracy and reliability compared to other forms of device. Future research should endeavour to utilise gold-standard criterion measures across a broader range of exercises (including weightlifting movements) and relative loads. Electronic supplementary material The online version of this article (10.1007/s40279-020-01382-w) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jonathon Weakley
- School of Behavioural and Health Sciences, Australian Catholic University, Building 211.1.26, Brisbane, QLD, Australia. .,Carnegie Applied Rugby Research (CARR) Centre, Institute of Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK.
| | - Matthew Morrison
- School of Behavioural and Health Sciences, Australian Catholic University, Building 211.1.26, Brisbane, QLD, Australia
| | - Amador García-Ramos
- Department of Sports Sciences and Physical Conditioning, Universidad Católica de la Santísima Concepción, Concepción, Chile.,Department of Physical Education and Sport, University of Granada, Granada, Spain
| | - Rich Johnston
- School of Behavioural and Health Sciences, Australian Catholic University, Building 211.1.26, Brisbane, QLD, Australia.,Carnegie Applied Rugby Research (CARR) Centre, Institute of Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | - Lachlan James
- Sport and Exercise Science, School of Allied Health, Human Services and Sport, La Trobe University, Melbourne, Australia
| | - Michael H Cole
- School of Behavioural and Health Sciences, Australian Catholic University, Building 211.1.26, Brisbane, QLD, Australia
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Martín-San Agustín R, Sánchez-Barbadora M, García-Vidal JA. Validity of an inertial system for measuring velocity, force, and power during hamstring exercises performed on a flywheel resistance training device. PeerJ 2020; 8:e10169. [PMID: 33083155 PMCID: PMC7549468 DOI: 10.7717/peerj.10169] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/22/2020] [Indexed: 12/19/2022] Open
Abstract
Background Inertial hamstring exercises promote functional changes leading to lower rates of hamstring injuries. However, variable training measurement systems have not been specifically validated for hamstring exercises. Accordingly, this study aimed to evaluate the validity of the Inertial Measurement System (IMS) to measure the velocity, force, and power during the performance of different hamstring exercises on a flywheel resistance training device. Methods Fifteen males (average age: 22.4 ± 2.5 years; body mass: 77.3 ± 9.8 kg; height: 179.5 ± 7.4 cm; weekly physical activity: 434.0 ± 169.2 min; years of strength training: 4.3 ± 2.2 years) performed the bilateral stiff-leg deadlift (SDL), 45° hip extension (HE), and unilateral straight knee bridge (SKB) in two sessions (familiarization and evaluation) with a 1-week interval between them. The velocity, force, and power (average and peak values) in the concentric and eccentric phases for each of the exercises were recorded simultaneously with IMS and MuscleLab. Results Consistency between IMS and MuscleLab was good to excellent for all variables, with r ranges from 0.824 to 0.966 in SDL, from 0.822 to 0.971 in HE, and from 0.806 to 0.969 in SKB. Acceptable levels of agreement between devices were observed in general for all exercises, the “bias” ranging from 1.1% to 13.2%. Although MuscleLab showed higher values than IMS for peak velocity, force and power values, the effect size was only relevant for 5 of the 36 parameters. IMS is a new and valid system to monitor inertial hamstring exercises on a new flywheel device. In this way, IMS could have potential practical applications for any professional or athlete who wants to monitor inertial hamstring exercises.
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Abbott JC, Wagle JP, Sato K, Painter K, Light TJ, Stone MH. Validation of Inertial Sensor to Measure Barbell Kinematics across a Spectrum of Loading Conditions. Sports (Basel) 2020; 8:sports8070093. [PMID: 32610449 PMCID: PMC7404789 DOI: 10.3390/sports8070093] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/23/2020] [Accepted: 06/28/2020] [Indexed: 11/29/2022] Open
Abstract
The aim of this study was to evaluate the level of agreement in measuring back squat kinematics between an inertial measurement unit (IMU) and a 3D motion capture system (3DMOCAP). Kinematic variables included concentric peak velocity (CPV), concentric mean velocity (CMV), eccentric peak velocity (EPV), eccentric mean velocity (EMV), mean propulsive velocity (MPV), and POP-100: a proprietary variable. Sixteen resistance-trained males performed an incrementally loaded one repetition maximum (1RM) squat protocol. A series of Pearson correlations, 2 × 4 RM ANOVA, Cohen’s d effect size differences, coefficient of variation (CV), and standard error of the estimate (SEE) were calculated. A large relationship existed for all variables between devices (r = 0.78–0.95). Between-device agreement for CPV worsened beyond 60% 1RM. The remaining variables were in agreement between devices with trivial effect size differences and similar CV magnitudes. These results support the use of the IMU, regardless of relative intensity, when measuring EMV, EPV, MPV, and POP-100. However, practitioners should carefully select kinematic variables of interest when using the present IMU device for velocity-based training (VBT), as certain measurements (e.g., CMV, CPV) do not possess practically acceptable reliability or accuracy. Finally, the IMU device exhibited considerable practical data collection concerns, as one participant was completely excluded and 13% of the remaining attempts displayed obvious internal error.
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11
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Shattock K, Tee JC. Autoregulation in Resistance Training: A Comparison of Subjective Versus Objective Methods. J Strength Cond Res 2020; 36:641-648. [PMID: 32058357 DOI: 10.1519/jsc.0000000000003530] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Shattock, K and Tee, JC. Autoregulation in resistance training: A comparison of subjective versus objective methods. J Strength Cond Res XX(X): 000-000, 2020-Autoregulation (AR) is a resistance training periodization approach that adjusts training prescription in response to individual rates of athlete adaptation. AR training prescription can make use of either subjective (rating of perceived exertion [RPE]) or objective (barbell velocity) intensity descriptors. The aim of this research was to compare the efficacy of these 2 approaches in improving sport-specific physical performance measures. Using a randomized crossover design, 20 amateur rugby union players completed two 6-week blocks of training with training intensity prescribed using either objective velocity-based (VB) (measured using a wearable accelerometer device) or objective RPE-based intensity prescriptions. Training volume was matched for both groups while training intensity was equivalent but prescribed using either VB or RPE measures. Performance measurements were countermovement jump (CMJ), 1 repetition maximum back squat and bench press, and 10-, 20-, and 40-m sprint. Testing was conducted before and immediately after each training block. The likelihood that observed changes in performance measures were meaningful was assessed using magnitude-based decisions. Both training programs induced practically meaningful improvements in CMJ (VB most likely +8.2, ±1.1%; RPE likely +3.8, ±0.9%), back squat (VB most likely +7.5, ±1.5%; RPE possibly +3.5, ±1.8%), and bench press (VB most likely +7.7, ±2.1%; RPE possibly +3.8, ±0.9%). Changes in sprint test performance were very likely trivial for both programs. Objective AR programming resulted in larger improvements in CMJ (likely 4.2, ±1.2%), squat (likely 3.7, ±1.5%) performance, and bench press (possibly 3.7, ±1.5%) performance. Autoregulation periodization improved strength and CMJ, but not sprint performance. Autoregulation effects are augmented through the use of objective intensity prescription.
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Affiliation(s)
- Kevin Shattock
- Carnegie Applied Rugby Research (CARR) Center, Institute for Sport, Physical Activity and Leisure, Carnegie School of Sport, Leeds Beckett University, Leeds, United Kingdom
| | - Jason C Tee
- Carnegie Applied Rugby Research (CARR) Center, Institute for Sport, Physical Activity and Leisure, Carnegie School of Sport, Leeds Beckett University, Leeds, United Kingdom.,Department of Sport Studies, Faculty of Applied Sciences, Durban University of Technology, South Africa
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12
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Reliability and Validity of Using the Push Band v2.0 to Measure Repetition Velocity in Free-Weight and Smith Machine Exercises. J Strength Cond Res 2019; 36:365-370. [PMID: 31860535 DOI: 10.1519/jsc.0000000000003436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hughes, LJ, Peiffer, JJ, and Scott, BR. Reliability and validity of using the Push Band v2.0 to measure repetition velocity in free-weight and Smith machine exercises. J Strength Cond Res XX(X): 000-000, 2019-The purpose of this study was to investigate the test-retest reliability and concurrent validity of using the Push Band device 2.0 (PUSH) to quantify repetition velocity across 4 common resistance training exercises performed using free-weight and Smith machine training modalities. Twenty well-trained men (age: 25.1 ± 2.9 years, height: 182.4 ± 6.0 cm, body mass: 77.9 ± 12.0 kg, training age: 5.2 ± 1.4 years) visited the laboratory on 6 occasions (3 free-weight and 3 Smith machine sessions). Baseline strength assessments were conducted in the first session with each modality for squat, bench press, overhead press, and prone row exercises. The subsequent sessions featured repetitions performed with 30, 60, and 90% 1-repetition maximum. During these sessions, velocity was measured simultaneously using a validated linear position transducer (LPT; considered the criterion for this study) and 2 PUSH devices, one in body mode (PUSHBODY) and the other bar mode (PUSHBAR). Test-retest reliability was examined using the intraclass correlation coefficient (ICC) and coefficient of variation (CV). The LPT demonstrated slightly greater reliability (ICC = 0.80-0.98, CV = 0.4-5.1%) than the PUSHBODY (ICC = 0.65-0.95, CV = 0.8-6.9%) and PUSHBAR (ICC = 0.50-0.93, CV = 0.7-7.1%) devices. Near-perfect correlations existed between velocity measured using LPT and PUSH devices (r = 0.96-0.99). No significant differences existed between mean velocity measures obtained using LPT and either PUSH device. The PUSH device can be used in either bar or body mode to obtain reliable and valid repetition velocity measures across a range of loads and exercises performed using either free weights or a Smith machine.
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