1
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Del Vecchio A, Enoka RM, Farina D. Specificity of early motor unit adaptations with resistive exercise training. J Physiol 2024; 602:2679-2688. [PMID: 38686581 DOI: 10.1113/jp282560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 04/10/2024] [Indexed: 05/02/2024] Open
Abstract
After exposure of the human body to resistive exercise, the force-generation capacity of the trained muscles increases significantly. Despite decades of research, the neural and muscular stimuli that initiate these changes in muscle force are not yet fully understood. The study of these adaptations is further complicated by the fact that the changes may be partly specific to the training task. For example, short-term strength training does not always influence the neural drive to muscles during the early phase (<100 ms) of force development in rapid isometric contractions. Here we discuss some of the studies that have investigated neuromuscular adaptations underlying changes in maximal force and rate of force development produced by different strength training interventions, with a focus on changes observed at the level of spinal motor neurons. We discuss the different motor unit adjustments needed to increase force or speed, and the specificity of some of the adaptations elicited by differences in the training tasks.
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Affiliation(s)
- Alessandro Del Vecchio
- Department Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Roger Maro Enoka
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Dario Farina
- Department of Bioengineering, Imperial College London, London, UK
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2
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Loturco I, Zabaloy S, Pereira LA, Moura TBMA, Mercer VP, Victor F, Zając A, Matusinski A, Freitas TT, Bishop C. Resistance Training Practices of Brazilian Olympic Sprint and Jump Coaches: Toward a Deeper Understanding of Their Choices and Insights (Part III). J Hum Kinet 2024; 90:183-214. [PMID: 38380293 PMCID: PMC10875694 DOI: 10.5114/jhk/182888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 01/20/2024] [Indexed: 02/22/2024] Open
Abstract
In the final part of this three-article collection on the training strategies of Brazilian Olympic sprint and jump coaches, we provide a detailed description of the resistance training methods and exercises most commonly employed by these speed experts. Always with the objective of maximizing the sprint and jump capabilities of their athletes, these experienced coaches primarily utilize variable, eccentric, concentric, machine-based, isometric, complex, and isoinertial resistance training methods in their daily practices. Squats (in their different forms), Olympic weightlifting, ballistics, hip thrusts, lunges, calf raises, core exercises, leg curls, stiff-leg deadlifts, and leg extension are the most commonly prescribed exercises in their training programs, during both the preparatory and competitive periods. Therefore, the current manuscript comprehensively describes and examines these methods, with the additional aim of extrapolating their application to other sports, especially those where sprint speed is a key performance factor.
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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
| | - Santiago Zabaloy
- Faculty of Physical Activity and Sports, University of Flores, Buenos Aires, Argentina
| | | | | | | | | | - Adam Zając
- Institute of Sport Sciences, The Jerzy Kukuczka Academy of Physical Education in Katowice, Katowice, Poland
| | - Aleksander Matusinski
- Department of Exercise and Sport Performance, The Jerzy Kukuczka Academy of Physical Education in Katowice, Katowice, Poland
| | - Tomás T. Freitas
- NAR—Nucleus of High Performance in Sport, 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
| | - Chris Bishop
- London Sport Institute, Middlesex University, London, United Kingdom
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3
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Warneke K, Wirth K, Keiner M, Lohmann LH, Hillebrecht M, Brinkmann A, Wohlann T, Schiemann S. Comparison of the effects of long-lasting static stretching and hypertrophy training on maximal strength, muscle thickness and flexibility in the plantar flexors. Eur J Appl Physiol 2023; 123:1773-1787. [PMID: 37029826 PMCID: PMC10363083 DOI: 10.1007/s00421-023-05184-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 03/16/2023] [Indexed: 04/09/2023]
Abstract
Maximal strength measured via maximal voluntary contraction is known as a key factor in competitive sports performance as well as injury risk reduction and rehabilitation. Maximal strength and hypertrophy are commonly trained by performing resistance training programs. However, literature shows that long-term, long-lasting static stretching interventions can also produce significant improvements in maximal voluntary contraction. The aim of this study is to compare increases in maximal voluntary contraction, muscle thickness and flexibility after 6 weeks of stretch training and conventional hypertrophy training. Sixty-nine (69) active participants (f = 30, m = 39; age 27.4 ± 4.4 years, height 175.8 ± 2.1 cm, and weight 79.5 ± 5.9 kg) were divided into three groups: IG1 stretched the plantar flexors continuously for one hour per day, IG2 performed hypertrophy training for the plantar flexors (5 × 10-12 reps, three days per week), while CG did not undergo any intervention. Maximal voluntary contraction, muscle thickness, pennation angle and flexibility were the dependent variables. The results of a series of two-way ANOVAs show significant interaction effects (p < 0.05) for maximal voluntary contraction (ƞ2 = 0.143-0.32, p < 0.006), muscle thickness (ƞ2 = 0.11-0.14, p < 0.021), pennation angle (ƞ2 = 0.002-0.08, p = 0.077-0.625) and flexibility (ƞ2 = 0.089-0.21, p < 0.046) for both the stretch and hypertrophy training group without significant differences (p = 0.37-0.99, d = 0.03-0.4) between both intervention groups. Thus, it can be hypothesized that mechanical tension plays a crucial role in improving maximal voluntary contraction and muscle thickness irrespective whether long-lasting stretching or hypertrophy training is used. Results show that for the calf muscle, the use of long-lasting stretching interventions can be deemed an alternative to conventional resistance training if the aim is to increase maximal voluntary contraction, muscle thickness and flexibility. However, the practical application seems to be strongly limited as a weekly stretching duration of up to 7 h a week is opposed by 3 × 15 min of common resistance training.
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Affiliation(s)
- Konstantin Warneke
- Institute for Exercise, Sport and Health, Leuphana University, 21335, Lüneburg, Germany.
| | - Klaus Wirth
- University of Applied Sciences Wiener Neustadt, Wiener Neustadt, Austria
| | - Michael Keiner
- Department of Sport Science, German University of Health and Sport, 85737, Ismaning, Germany
| | - Lars H Lohmann
- Institute of Sports Science, Carl von Ossietzky University of Oldenburg, 26129, Oldenburg, Germany
| | - Martin Hillebrecht
- University Sports Center, Carl von Ossietzky University of Oldenburg, 26129, Oldenburg, Germany
| | - Anna Brinkmann
- Assistive Systems and Medical Device Technology, Carl von Ossietzky University of Oldenburg, 26129, Oldenburg, Germany
| | - Tim Wohlann
- Institute for Exercise, Sport and Health, Leuphana University, 21335, Lüneburg, Germany
| | - Stephan Schiemann
- Institute for Exercise, Sport and Health, Leuphana University, 21335, Lüneburg, Germany
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4
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Warneke K, Wagner CM, Keiner M, Hillebrecht M, Schiemann S, Behm DG, Wallot S, Wirth K. Maximal strength measurement: A critical evaluation of common methods-a narrative review. Front Sports Act Living 2023; 5:1105201. [PMID: 36873661 PMCID: PMC9981657 DOI: 10.3389/fspor.2023.1105201] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 01/30/2023] [Indexed: 02/19/2023] Open
Abstract
Measuring maximal strength (MSt) is a very common performance diagnoses, especially in elite and competitive sports. The most popular procedure in test batteries is to test the one repetition maximum (1RM). Since testing maximum dynamic strength is very time consuming, it often suggested to use isometric testing conditions instead. This suggestion is based on the assumption that the high Pearson correlation coefficients of r ≥ 0.7 between isometric and dynamic conditions indicate that both tests would provide similar measures of MSt. However, calculating r provides information about the relationship between two parameters, but does not provide any statement about the agreement or concordance of two testing procedures. Hence, to assess replaceability, the concordance correlation coefficient (ρ c) and the Bland-Altman analysis including the mean absolute error (MAE) and the mean absolute percentage error (MAPE) seem to be more appropriate. Therefore, an exemplary model based on r = 0.55 showed ρ c = 0.53, A MAE of 413.58 N and a MAPE = 23.6% with a range of -1,000-800 N within 95% Confidence interval (95%CI), while r = 0.7 and 0.92 showed ρ c = 0.68 with a MAE = 304.51N/MAPE = 17.4% with a range of -750 N-600 N within a 95% CI and ρ c = 0.9 with a MAE = 139.99/MAPE = 7.1% with a range of -200-450 N within a 95% CI, respectively. This model illustrates the limited validity of correlation coefficients to evaluate the replaceability of two testing procedures. Interpretation and classification of ρ c, MAE and MAPE seem to depend on expected changes of the measured parameter. A MAPE of about 17% between two testing procedures can be assumed to be intolerably high.
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Affiliation(s)
- Konstantin Warneke
- Department for Exercise, Sport and Health, Leuphana University Lüneburg, Lüneburg, Germany
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. Johns, NL, Canada
| | - Carl-Maximilian Wagner
- Department of Training Science, German University of Health and Sport, Berlin, Baden-Württemberg, Germany
| | - Michael Keiner
- Department of Training Science, German University of Health and Sport, Berlin, Baden-Württemberg, Germany
| | - Martin Hillebrecht
- University Sports Center, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | - Stephan Schiemann
- Department for Exercise, Sport and Health, Leuphana University Lüneburg, Lüneburg, Germany
| | - David George Behm
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. Johns, NL, Canada
| | | | - Klaus Wirth
- Faculty of Training and Sports Science, University of Applied Science Wiener Neustadt, Vienna, Austria
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Del Vecchio A, Casolo A, Dideriksen JL, Aagaard P, Felici F, Falla D, Farina D. Lack of increased rate of force development after strength training is explained by specific neural, not muscular, motor unit adaptations. J Appl Physiol (1985) 2021; 132:84-94. [PMID: 34792405 DOI: 10.1152/japplphysiol.00218.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
While maximal force increases following short-term isometric strength training, the rate of force development (RFD) may remain relatively unaffected. The underlying neural and muscular mechanisms during rapid contractions after strength training are largely unknown. Since strength training increases the neural drive to muscles, it may be hypothesized that there are distinct neural or muscular adaptations determining the change in RFD independently of an increase in maximal force. Therefore, we examined motor unit population data acquired from surface electromyography during the rapid generation of force before and after four weeks of strength training. We observed that strength training did not change the RFD because it did not influence the number of motor units recruited per second or their initial discharge rate during rapid contractions. While strength training did not change motoneuron behaviour in the force increase phase of rapid contractions, it increased the discharge rate of motoneurons (by ~4 spikes/s) when reaching the plateau phase (~150 ms) of the rapid contractions, determining an increase in maximal force production. Computer simulations with a motor unit model that included neural and muscular properties, closely matched the experimental observations and demonstrated that the lack of change in RFD following training is primarily mediated by an unchanged maximal recruitment speed of motoneurons. These results demonstrate that maximal force and contraction speed are determined by different adaptations in motoneuron behaviour following strength training and indicate that increases in the recruitment speed of motoneurons are required to evoke training-induced increases in RFD.
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Affiliation(s)
- Alessandro Del Vecchio
- Department of Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander University, Erlangen, Bavaria, Germany
| | - Andrea Casolo
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Per Aagaard
- Department of Sports Science and Clinical Biomechanics, Muscle Physiology and Biomechanics Research Unit, University of Southern Denmark, Odense, Denmark
| | - Francesco Felici
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Rome, Italy
| | - Deborah Falla
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Dario Farina
- Department of Bioengineering, Imperial College London, London, United Kingdom
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6
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Miller RH, Russell Esposito E. Transtibial limb loss does not increase metabolic cost in three-dimensional computer simulations of human walking. PeerJ 2021; 9:e11960. [PMID: 34430088 PMCID: PMC8349165 DOI: 10.7717/peerj.11960] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/21/2021] [Indexed: 11/20/2022] Open
Abstract
Loss of a lower limb below the knee, i.e., transtibial limb loss, and subsequently walking with a prosthesis, is generally thought to increase the metabolic cost of walking vs. able-bodied controls. However, high-functioning individuals with limb loss such as military service members often walk with the same metabolic cost as controls. Here we used a 3-D computer model and optimal control simulation approach to test the hypothesis that transtibial limb loss in and of itself causes an increase in metabolic cost of walking. We first generated N = 36 simulations of walking at 1.45 m/s using a “pre-limb loss” model, with two intact biological legs, that minimized deviations from able-bodied experimental walking mechanics with minimum muscular effort. We then repeated these simulations using a “post-limb loss” model, with the right leg’s ankle muscles and joints replaced with a simple model of a passive transtibial prosthesis. No other changes were made to the post-limb loss model’s remaining muscles or musculoskeletal parameters compared to the pre-limb loss case. Post-limb loss, the gait deviations on average increased by only 0.17 standard deviations from the experimental means, and metabolic cost did not increase (3.58 ± 0.10 J/m/kg pre-limb loss vs. 3.59 ± 0.12 J/m/kg post-limb loss, p = 0.65). The results suggest that transtibial limb loss does not directly lead to an increase in metabolic cost, even when deviations from able-bodied gait mechanics are minimized. High metabolic costs observed in individuals with transtibial limb loss may be due to secondary changes in strength or general fitness after limb loss, modifiable prosthesis issues, or to prioritization of factors that affect locomotor control other than gait deviations and muscular effort.
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Affiliation(s)
- Ross H Miller
- Department of Kinesiology, University of Maryland, College Park, MD, United States of America.,Neuroscience and Cognitive Science Program, University of Maryland, College Park, MD, United States of America
| | - Elizabeth Russell Esposito
- Extremity Trauma and Amputation Center of Excellence, Fort Sam Houston, TX, United States of America.,Center for Limb Loss and Mobility, Seattle, WA, United States of America.,Department of Mechanical Engineering, University of Washington, Seattle, WA, United States of America
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7
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Martins-Costa HC, Lanza MB, Diniz RCR, Lacerda LT, Gomes MC, Lima FV, Chagas MH. The effect of different resistance training protocols equalized by time under tension on the force-position relationship after 10 weeks of training period. Eur J Sport Sci 2021; 22:846-856. [PMID: 33779514 DOI: 10.1080/17461391.2021.1910346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This study investigated the impact of performing two equalized resistance training (RT) protocols for 10 weeks that differ only by repetition duration and number in the force-position and EMG-position relationship. Participants performed an equalized (36 s of time under tension; 3-4 sets; 3 min between sets; 50-55% of one-repetition maximum; 3× week) RT intervention on the bench press and the only different change between protocols was repetition number (RN; 12 vs.6) or duration (RD; 3 s vs. 6 s). Two experimental groups (RN12RD3, n = 12; and RN6RD6, n = 12) performed the RT, while one group was the control (Control, n = 11). Maximal isometric contractions at 10%, 50% and 90% of total bench press range of motion were performed pre- and post-RT, while electromyography was recorded. It demonstrated an increase in isometric force (+14% to 24%, P < 0.001) shifting up the force-position relationship of the training groups after RT, although no difference was between training groups compared to the Control. Neuromuscular activation from pectoralis major presented an increase after training for both RT groups (+44%; P < 0.001) compared to the Control. However, although not significantly different, triceps brachii also presented an increase depending on the protocol (+25%). In conclusion, 10 weeks of an equalized RT with longer RN and shorter RD (or opposite) similarly increases the ability to produce maximal isometric force during the bench exercise across different angles, while neuromuscular activation of the pectoralis major partially explained the shift-up of the force-position relationship after training.
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Affiliation(s)
- Hugo C Martins-Costa
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil.,Department of Physical Education, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Brazil
| | - Marcel B Lanza
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil.,Department of Physical Therapy and Rehabilitation, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Rodrigo C R Diniz
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Lucas T Lacerda
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil.,Department of Physical Education, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Brazil.,Department of Physical Education and Sports, Technological Education Federal Center of Minas Gerais, Belo Horizonte, Brazil.,Department of Physical Education, State University of Minas Gerais, Divinópolis, Brazil
| | - Mateus C Gomes
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Fernando V Lima
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Mauro H Chagas
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil
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8
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Martins-Costa HC, Lacerda LT, Diniz RCR, Lima FV, Andrade AG, Peixoto G, Gomes M, Lanza MB, Bemben M, Chagas MH. Equalization of Training Protocols by Time Under Tension Determines the Magnitude of Changes in Strength and Muscular Hypertrophy. J Strength Cond Res 2021; 36:1770-1780. [PMID: 34932279 DOI: 10.1519/jsc.0000000000004004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Martins-Costa, HC, Lacerda, LT, Diniz, RCR, Lima, FV, Andrade, AGP, Peixoto, GH, Gomes, MC, Lanza, MB, Bemben, MG, and Chagas, MH. Equalization of training protocols by time under tension determines the magnitude of changes in strength and muscular hypertrophy. J Strength Cond Res XX(X): 000-000, 2021-The aim of this study was to investigate the effects of 2 training protocols equalized by tension (TUT) on maximal strength (1 repetition maximum [RM]), regional cross-sectional areas (proximal, middle, and distal), and total cross-sectional areas (sum of the regional cross-sectional areas) of the pectoralis major and triceps brachii muscles. Thirty-eight men untrained in resistance training participated in the study and were allocated under 3 conditions: Protocol 3s (n = 11; 12 repetitions; 3s repetition duration), Protocol 6s (n = 11; 6 repetitions; 6s repetition duration), and Control (n = 11; no training). Training protocols (10 weeks; bench press exercise) were equated for TUT (36 seconds per set), number of sets (3-4), intensity (50-55% of 1RM), and rest between sets (3 minutes). Analysis of variance was used to examine a percentage change in variables of interest across the 3 groups with an alpha level of 0.05 used to establish statistical significance. Protocols 3s and 6s showed no differences in the increase of total and regional muscle cross-sectional areas. There were no differences in regional hypertrophy of the pectoralis major muscle. In the triceps brachii muscle, the increase in distal cross-sectional area was greater when compared with the middle and proximal regions. Both experimental groups had similar increases in the 1RM test. In conclusion, training protocols with the same TUT promote similar strength gains and muscle hypertrophy. Moreover, considering that the protocols used different numbers of repetitions, the results indicate that training volumes cannot be considered separately from TUT when evaluating neuromuscular adaptations.
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Affiliation(s)
- Hugo C Martins-Costa
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Department of Physical Education, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Lucas T Lacerda
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Department of Physical Education, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Department of Physical Education and Sports, Technological Education Federal Center of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Department of Physical Education, State University of Minas Gerais, Divinopolis, Brazil
| | - Rodrigo C R Diniz
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Fernando V Lima
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Andre G Andrade
- Department of Physical Education, State University of Minas Gerais, Divinopolis, Brazil
| | - Gustavo Peixoto
- Biomechanics Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Mateus Gomes
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Marcel B Lanza
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Department of Physical Therapy and Rehabilitation, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Michael Bemben
- Department of Health and Exercise Science, University of Oklahoma, Norman, Oklahoma
| | - Mauro H Chagas
- Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Biomechanics Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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9
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Mausehund L, Werkhausen A, Bartsch J, Krosshaug T. Understanding Bench Press Biomechanics-The Necessity of Measuring Lateral Barbell Forces. J Strength Cond Res 2021; 36:2685-2695. [PMID: 33555823 DOI: 10.1519/jsc.0000000000003948] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Mausehund, L, Werkhausen, A, Bartsch, J, and Krosshaug, T. Understanding bench press biomechanics-The necessity of measuring lateral barbell forces. J Strength Cond Res XX(X): 000-000, 2020-The purpose of this study was to advance the expertise of the bench press exercise by complementing electromyographic (EMG) with net joint moment (NJM) and strength normalized NJM (nNJM) measurements, thus establishing the magnitude of the elbow and shoulder muscular loads and efforts. Normalized NJMs were determined as the ratio of the bench press NJMs to the maximum NJMs produced during maximum voluntary isokinetic contractions. Furthermore, we wanted to assess how changes in grip width and elbow positioning affected elbow and shoulder NJMs and nNJMs, and muscle activity of the primary movers. Thirty-five strength-trained adults performed a 6-8 repetition maximum set of each bench press variation, while elbow and shoulder NJMs and EMG activity of 7 upper extremity muscles were recorded. The results show that all bench press variations achieved high elbow and shoulder muscular efforts. A decrease in grip width induced larger elbow NJMs, and larger EMG activity of the lateral head of the triceps brachii, anterior deltoid, and clavicular head of the pectoralis major (p ≤ 0.05). An increase in grip width elicited larger shoulder NJMs and nNJMs, and larger EMG activity of the abdominal head of the pectoralis major (p ≤ 0.05). In conclusion, all bench press variations may stimulate strength gains and hypertrophy of the elbow extensors and shoulder flexors and horizontal adductors. However, greater adaptations of the elbow extensors and shoulder flexors may be expected when selecting narrower grip widths, whereas wider grip widths may induce greater adaptations of the shoulder horizontal adductors.
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Affiliation(s)
- Lasse Mausehund
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway; and Department of Sports Medicine, Oslo Sports Trauma Research Centre, Norwegian School of Sports Sciences, Oslo, Norway
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10
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Lanza MB, Addison O, Ryan AS, J Perez W, Gray V. Kinetic, muscle structure, and neuromuscular determinants of weight transfer phase prior to a lateral choice reaction step in older adults. J Electromyogr Kinesiol 2020; 55:102484. [PMID: 33176230 PMCID: PMC8209691 DOI: 10.1016/j.jelekin.2020.102484] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/06/2020] [Accepted: 10/14/2020] [Indexed: 12/25/2022] Open
Abstract
The present study aimed to investigate the association between rate of torque development (RTD), rate of activation (RoA), and muscle structure [muscle cross-sectional area (CSA), intramuscular fat (IMAT) and high density lean muscle (HDL)] with the weight transfer phase (WTP) during a choice reaction step test (CST) in older adults. Fifteen healthy older adults (7 females) participated in this study. Stance leg hip adductors RTD at 100, 150, and 200 ms, showed a significant inverse correlation with WTP (r ≥ 0.658, P ≤ 0.010). There was a significant inverse relationship between WTP and adductor magnus and tensor fascia latae RoA at all time points (RoA0-50-RoA0-200; r ≥ 0.707, P ≤ 0.033). In contrast, the WTP was not significantly associated with the hip abductor RTD, gluteus medius RoA, or muscle structure (CSA, IMAT, and HDL). Swing leg showed no significant relationship between WTP and RTD, RoA or muscle structure of the hip abductor or adductor muscles. In conclusion, the present study showed that hip adductor torque-time capacity, as well as neuromuscular activation of the adductor magnus and tensor fascia latae of the stance leg during a maximal isometric test, is associated with the ability to transfer body weight before a step to the side occurs.
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Affiliation(s)
- Marcel B Lanza
- Department of Physical Therapy and Rehabilitation, University of Maryland Baltimore, Baltimore, United States.
| | - Odessa Addison
- Department of Physical Therapy and Rehabilitation, University of Maryland Baltimore, Baltimore, United States; Baltimore Geriatric Research, Education, and Clinical Center, VAHMC, Baltimore, MD, United States
| | - Alice S Ryan
- Department of Medicine, University of Maryland School of Medicine, Division of Gerontology and Geriatric Medicine, United States; Baltimore Geriatric Research, Education, and Clinical Center, VAHMC, Baltimore, MD, United States
| | - William J Perez
- Baltimore Geriatric Research, Education, and Clinical Center, VAHMC, Baltimore, MD, United States
| | - Vicki Gray
- Department of Physical Therapy and Rehabilitation, University of Maryland Baltimore, Baltimore, United States
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Placing Greater Torque at Shorter or Longer Muscle Lengths? Effects of Cable vs. Barbell Preacher Curl Training on Muscular Strength and Hypertrophy in Young Adults. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17165859. [PMID: 32823490 PMCID: PMC7460162 DOI: 10.3390/ijerph17165859] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/07/2020] [Accepted: 08/10/2020] [Indexed: 12/28/2022]
Abstract
Muscular strength and hypertrophy following resistance training may be obtained in different degrees depending on the approach performed. This study was designed to compare the responses of the biceps brachii to two preacher curl exercises, one performed on a cable-pulley system (CAB; in which a greater torque was applied during the exercise when elbows were flexed and biceps shortened) and one performed with a barbell (BAR; in which greater torque was applied when the elbows were extended and biceps stretched). Thirty-five young adults (CAB: 13 men, 5 women; BAR: 12 men, 5 women; age = 24 ± 5 years) performed a resistance training program three times per week for 10 weeks, with preacher curl exercises performed in three sets of 8–12 repetitions. Outcomes measured included elbow flexion peak isokinetic torque at angles of 20°, 60°, and 100° (considering 0° as elbow extended), and biceps brachii thickness (B-mode ultrasound). Following the training period, there were significant increases for both groups in elbow flexion peak torque at the 20° (CAB: 30%; BAR = 39%; p = 0.046), 60° (CAB: 27%; BAR = 32%; p = 0.874), and 100° (CAB: 17%; BAR = 19%; p = 0.728), and biceps brachii thickness (CAB: 7%; BAR = 8%; p = 0.346). In conclusion, gains in muscular strength were greater for BAR only at longer muscle length, whereas hypertrophy was similar regardless of whether torque emphasis was carried out in the final (CAB) or initial (BAR) degrees of the range of motion of the preacher curl in young adults.
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Orssatto LBR, Wiest MJ, Moura BM, Collins DF, Diefenthaeler F. Neuromuscular determinants of explosive torque: Differences among strength-trained and untrained young and older men. Scand J Med Sci Sports 2020; 30:2092-2100. [PMID: 32749004 DOI: 10.1111/sms.13788] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 07/22/2020] [Accepted: 07/27/2020] [Indexed: 02/03/2023]
Abstract
This study compared the differences in neural and muscular mechanisms related to explosive torque in chronically strength-trained young and older men (>5 years). Fifty-four participants were allocated into four groups according to age and strength training level: older untrained (n = 14; 65.6 ± 2.9 years), older trained (n = 12; 63.6 ± 3.8 years), young untrained (n = 14; 26.2 ± 3.7 years), and young trained (n = 14; 26.7 ± 3.4 years). Knee extension isometric voluntary explosive torque (absolute and normalized as a percentage of maximal voluntary torque) was assessed at the beginning of the contraction (ie, 50, 100, and 150 ms-T50, T100, and T150, respectively), and surface electromyogram (sEMG) amplitude (normalized as a percentage of sEMG recorded during maximal voluntary isometric contraction) at 0-50, 50-100, and 100-150 time windows. Supramaximal electrically evoked T50 was assessed with octet trains delivered to the femoral nerve (8 pulses at 300 Hz). Voluntary T50, T100, and T150 were higher for trained than untrained in absolute (P < 0.001) and normalized (P < 0.030) terms, accompanied by higher sEMG at 0-50, 50-100, and 100-150 ms (P < 0.001), and voluntary T50/octet T50 ratio for trained. Greater octet T50 was observed for the young trained (P < 0.001) but not for the older trained (P = 0.273) compared to their untrained counterparts. Age effect was observed for voluntary T50, T100, and T150 (P < 0.050), but normalization removed these differences (P > 0.417). Chronically strength-trained young and older men presented a greater explosive torque than their untrained pairs. In young trained, the greater explosive performance was attributed to enhanced muscular and neural mechanisms, while in older trained to neural mechanisms only.
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Affiliation(s)
- Lucas B R Orssatto
- School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Matheus J Wiest
- Neural Engineering & Therapeutic Team, KITE, Toronto Rehab, University Health Network, Toronto, ON, Canada
| | - Bruno M Moura
- Biomechanics Laboratory, Federal University of Santa Catarina, Florianópolis, Brazil
| | - David F Collins
- Human Neurophysiology Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada
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Kordi M, Folland JP, Goodall S, Menzies C, Patel TS, Evans M, Thomas K, Howatson G. Cycling‐specific isometric resistance training improves peak power output in elite sprint cyclists. Scand J Med Sci Sports 2020; 30:1594-1604. [DOI: 10.1111/sms.13742] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/19/2020] [Accepted: 05/29/2020] [Indexed: 01/15/2023]
Affiliation(s)
- Mehdi Kordi
- Department of Sport, Exercise and Rehabilitation Northumbria University Newcastle UK
- Royal Dutch Cycling Federation (KNWU) Papendal The Netherlands
| | - Jonathan P Folland
- School of Sport, Exercise & Health Sciences Loughborough University Loughborough UK
| | - Stuart Goodall
- Department of Sport, Exercise and Rehabilitation Northumbria University Newcastle UK
| | - Campbell Menzies
- Centre for Sport, Exercise and Life Sciences Coventry University Coventry UK
| | | | | | - Kevin Thomas
- Department of Sport, Exercise and Rehabilitation Northumbria University Newcastle UK
| | - Glyn Howatson
- Department of Sport, Exercise and Rehabilitation Northumbria University Newcastle UK
- Water Research Group North West University Potchefstroom South Africa
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Muscle alterations induced by electrostimulation are lower at short quadriceps femoris length. Eur J Appl Physiol 2019; 120:325-335. [DOI: 10.1007/s00421-019-04277-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 11/27/2019] [Indexed: 10/25/2022]
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