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Montalvo-Alonso JJ, Ferragut C, del Val-Manzano M, Valadés D, Roberts J, Pérez-López A. Sex Differences in the Ergogenic Response of Acute Caffeine Intake on Muscular Strength, Power and Endurance Performance in Resistance-Trained Individuals: A Randomized Controlled Trial. Nutrients 2024; 16:1760. [PMID: 38892692 PMCID: PMC11174740 DOI: 10.3390/nu16111760] [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: 04/25/2024] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
BACKGROUND This study assessed the impact of acute caffeine intake on muscular strength, power, and endurance performance between resistance-trained male and female individuals according to load in upper- and lower-body exercises. METHODS Here, 76 resistance-trained individuals (38 females, 38 males) participated in a study comparing caffeine and a placebo. Each received either 3 mg/kg of caffeine or a placebo 60 min before tests measuring muscular strength and power through bench press and back squat exercises at different intensities (25%, 50%, 75%, 90% 1RM). Muscular endurance at 65% 1RM was also assessed by performing reps until reaching task failure. RESULTS Compared to placebo, caffeine increased mean, peak and time to reach peak velocity and power output (p < 0.01, ηp2 = 0.242-0.293) in the muscular strength/power test in males and females. This effect was particularly observed in the back squat exercise at 50%, 75% and 90% 1RM (2.5-8.5%, p < 0.05, g = 1.0-2.4). For muscular endurance, caffeine increased the number of repetitions, mean velocity and power output (p < 0.001, ηp2 = 0.177-0.255) in both sexes and exercises (3.0-8.9%, p < 0.05, g = 0.15-0.33). CONCLUSIONS Acute caffeine intake resulted in a similar ergogenic effect on muscular strength, power, and endurance performance in upper- and lower-body exercises for male and female resistance-trained participants.
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Affiliation(s)
- Juan Jesús Montalvo-Alonso
- Universidad de Alcalá, Facultad de Medicina y Ciencias de la Salud, Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, 28801 Madrid, Spain; (J.J.M.-A.); (C.F.); (M.d.V.-M.); (D.V.)
| | - Carmen Ferragut
- Universidad de Alcalá, Facultad de Medicina y Ciencias de la Salud, Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, 28801 Madrid, Spain; (J.J.M.-A.); (C.F.); (M.d.V.-M.); (D.V.)
| | - Marta del Val-Manzano
- Universidad de Alcalá, Facultad de Medicina y Ciencias de la Salud, Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, 28801 Madrid, Spain; (J.J.M.-A.); (C.F.); (M.d.V.-M.); (D.V.)
| | - David Valadés
- Universidad de Alcalá, Facultad de Medicina y Ciencias de la Salud, Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, 28801 Madrid, Spain; (J.J.M.-A.); (C.F.); (M.d.V.-M.); (D.V.)
| | - Justin Roberts
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Cambridge CB1 1PT, UK;
| | - Alberto Pérez-López
- Universidad de Alcalá, Facultad de Medicina y Ciencias de la Salud, Departamento de Ciencias Biomédicas, Área de Educación Física y Deportiva, 28801 Madrid, Spain; (J.J.M.-A.); (C.F.); (M.d.V.-M.); (D.V.)
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Francisco R, Jesus F, Nunes CL, Santos P, Alvim M, Campa F, Schoeller DA, Lukaski H, Mendonca GV, Sardinha LFCB, Silva AMLDA. H2OAthletes study protocol: effects of hydration changes on neuromuscular function in athletes. Br J Nutr 2024; 131:1579-1590. [PMID: 38299306 DOI: 10.1017/s0007114524000308] [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: 02/02/2024]
Abstract
We aim to understand the effects of hydration changes on athletes' neuromuscular performance, on body water compartments, fat-free mass hydration and hydration biomarkers and to test the effects of the intervention on the response of acute dehydration in the hydration indexes. The H2OAthletes study (clinicaltrials.gov ID: NCT05380089) is a randomised controlled trial in thirty-eight national/international athletes of both sexes with low total water intake (WI) (i.e. < 35·0 ml/kg/d). In the intervention, participants will be randomly assigned to the control (CG, n 19) or experimental group (EG, n 19). During the 4-day intervention, WI will be maintained in the CG and increased in the EG (i.e. > 45·0 ml/kg/d). Exercise-induced dehydration protocols with thermal stress will be performed before and after the intervention. Neuromuscular performance (knee extension/flexion with electromyography and handgrip), hydration indexes (serum, urine and saliva osmolality), body water compartments and water flux (dilution techniques, body composition (four-compartment model) and biochemical parameters (vasopressin and Na) will be evaluated. This trial will provide novel evidence about the effects of hydration changes on neuromuscular function and hydration status in athletes with low WI, providing useful information for athletes and sports-related professionals aiming to improve athletic performance.
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Affiliation(s)
- Rúben Francisco
- Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, 1499-002 Cruz-Quebrada, Lisbon, Portugal
| | - Filipe Jesus
- Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, 1499-002 Cruz-Quebrada, Lisbon, Portugal
| | - Catarina L Nunes
- Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, 1499-002 Cruz-Quebrada, Lisbon, Portugal
| | - Paulo Santos
- Neuromuscular Research Lab, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
| | - Marta Alvim
- National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - Francesco Campa
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Dale A Schoeller
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Henry Lukaski
- Department of Kinesiology and Public Health Education, Hyslop Sports Center, University of North Dakota, Grand Forks, ND, USA
| | - Goncalo V Mendonca
- Neuromuscular Research Lab, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
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Pi Q, Xu J, Sha M, Liu X. Relationship between a body shape index and muscle strength index in Chinese university students: a cross-sectional survey. BMC Sports Sci Med Rehabil 2024; 16:48. [PMID: 38360702 PMCID: PMC10870512 DOI: 10.1186/s13102-024-00837-1] [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: 12/12/2023] [Accepted: 02/02/2024] [Indexed: 02/17/2024]
Abstract
BACKGROUND The problem of overweight obesity and decrease in muscle strength among university students has become an indisputable fact. In this study, a comprehensive index reflecting obesity degree a body shape index (ABSI) and a comprehensive index reflecting muscle strength muscle strength index (MSI) were studied to analyze the cross-sectional correlations existing between them. METHODS This study began recruiting participants and conducting the test survey in April 2022 and closed in July 2022. Basic condition, height, weight, waist circumference, grip strength, pull-up (boys), bent-leg sit-up (girls), and standing long jump were tested on 12,046 (boys: 6011, 49.90%) university students aged 19-22 years in China, and ABSI and MSI were calculated separately. ABSI was categorized into 5 groups according to age and sex, namely ABSI < 5th percentile (A), 5th ≤ ABSI < 25th percentile (B), 25th ≤ ABSI < 75th percentile (C), 75th ≤ ABSI < 95th percentile (D) and ABSI ≥ 95th percentile (E). The comparison of MSI between different ABSI groups was performed using effect size, and the association between them was performed by curve estimation analysis. RESULTS The association between ABSI and MSI of Chinese university students showed an inverted "U" curve. The effect of increased ABSI on MSI was greater in university girls compared to boys. The ABSI of boys was (0.080 ± 0.010) and MSI was (-0.005 ± 2.080); the ABSI of girls was (0.079 ± 0.008) and MSI was (-0.017 ± 1.867). Overall, university students ABSI was at a relatively high point for MSI between 0.050 and 0.100. The university students ABSI at 0.150 had an MSI of -1.229 for boys and - 2.779 for girls. CONCLUSION The ABSI of Chinese university students showed an inverted "U"-shaped curve relationship with MSI, and university students with low or high ABSI had lower MSI. The effect of increasing ABSI on the decrease of MSI was more obvious for girls than for boys.
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Affiliation(s)
- Qing Pi
- School of Art, Shangrao Preschool Education College, 334000, Jiangxi Shangrao, P. R. China
| | - Jiali Xu
- School of Physical Education, Shangrao Normal University, 334001, Jiangxi Shangrao, P. R. China
| | - Mian Sha
- School of Physical Education, Shangrao Normal University, 334001, Jiangxi Shangrao, P. R. China
| | - Xiangdong Liu
- Department of Physical Education, Pingxiang University, 337055, Jiangxi Shangrao, P. R. China.
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Lundberg TR, Larsson G, Alstermark R, Mandić M, Fernandez-Gonzalo R. Relationship between maximal oxygen uptake, within-set fatigue and between-set recovery during resistance exercise in resistance-trained men and women. BMC Sports Sci Med Rehabil 2024; 16:45. [PMID: 38347629 PMCID: PMC10863198 DOI: 10.1186/s13102-024-00830-8] [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: 09/04/2023] [Accepted: 01/29/2024] [Indexed: 02/15/2024]
Abstract
BACKGROUND The primary aim of this study was to examine the relationship between maximal oxygen update (V̇O2max) and within-set fatigue and between-set recovery during resistance exercise in men and women. METHODS We examined the relationship between V̇O2max and various indices of fatigue and recovery during parallel squats (3 sets, 90 s rest, 70% of 1RM to failure) and isokinetic knee extensions (3 × 10 maximal repetitions at 60 deg/s, 45 s rest) in 28 (age 27.0 ± 3.6 years) resistance-trained subjects (14 men and 14 women). We also examined whether there were sex differences in within-set fatigue and between-set recovery. RESULTS V̇O2max was weakly related to recovery and fatigue in both men and women (range of P-values for V̇O2max as a covariate; 0.312-0.998, range of R-values, 0.005-0.604). There were no differences between the sexes in fatigue within a set for the squat, but men showed less within-set fatigue than women in the first set of the isokinetic knee extension exercise (~ 8% torque loss difference, main effect of sex P = 0.034). Regarding recovery between sets, men showed greater relative peak power (P = 0.016) and peak torque (P = 0.034) loss between sets in both exercises, respectively, compared to women. Women also tended to complete more repetitions than men (main effect of sex, P = 0.057). Loss of peak torque between sets in knee extension was evident in both absolute and relative (%) values in men but not in women. CONCLUSIONS Our study suggests that aerobic capacity is weakly associated with within-set fatigue and between-set recovery in resistance training in both men and women. Women and men show comparable levels of within-set fatigue in the multi-joint squat, but women show more within-set fatigue during the single-joint isokinetic knee extension compared with men. In contrast, women recover better than men between sets in both exercises.
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Affiliation(s)
- Tommy R Lundberg
- Department of Laboratory Medicine, Division of Clinical Physiology, ANA FUTURA, Karolinska Institutet, Stockholm, Huddinge, 14152, Sweden.
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden.
| | - Gustav Larsson
- Department of Laboratory Medicine, Division of Clinical Physiology, ANA FUTURA, Karolinska Institutet, Stockholm, Huddinge, 14152, Sweden
| | - Rasmus Alstermark
- Department of Laboratory Medicine, Division of Clinical Physiology, ANA FUTURA, Karolinska Institutet, Stockholm, Huddinge, 14152, Sweden
| | - Mirko Mandić
- Department of Laboratory Medicine, Division of Clinical Physiology, ANA FUTURA, Karolinska Institutet, Stockholm, Huddinge, 14152, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Rodrigo Fernandez-Gonzalo
- Department of Laboratory Medicine, Division of Clinical Physiology, ANA FUTURA, Karolinska Institutet, Stockholm, Huddinge, 14152, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
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Pimenta R, Lopes T, Veloso AP. Fatigue effects on the knee flexors neuromuscular parameters during repeated sprinting. BMC Sports Sci Med Rehabil 2024; 16:3. [PMID: 38169410 PMCID: PMC10762908 DOI: 10.1186/s13102-023-00789-y] [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: 04/18/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024]
Abstract
BACKGROUND To identify at which point fatigue on neuromuscular parameters occurs in the knee flexors during a repeated sprint protocol. METHODS Physical active males without previous hamstring strain injury were recruited. Neuromuscular parameters such as peak torque (PT) and rate of torque development (RTD) were assessed after every two sprints in a 5 × (2 x 30 m) repeated sprint protocol. RESULTS Twenty physical active males participated in the study. A significant effect of sprint number was found (p < 0.001; η2p = 0.643) with a decreased sprint speed by 6.9% from fastest to slowest sprint. No significant differences were observed in the time between finishing the sprint and performing the first MVIC (46.3 ± 4.7s; p = 0.423), nor in the time between finishing a set and starting the next set (121.2 ± 7.6s; p = 0.503). Regarding neuromuscular parameters, the only significant difference found was in PT between before and after two sprints (117.95 ± 5.61 N⋅m vs. 110.64 ± 5.71 N⋅m; p = 0.048, d = 0.289) and on RTD 0-50ms before and after ten sprints (465.78 ± 223.76 N⋅m/s vs. 382.30 ± 189.56 N⋅m/s; p = 0.008; η2p = 0.149). CONCLUSIONS A recovery time of 46s between sprints and testing neuromuscular parameters (due to experimental design) seems sufficient to restore the neuromuscular system. Therefore, it can be suggested that time recovery is the principal factor in detecting fatigue on neuromuscular parameters.
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Affiliation(s)
- Ricardo Pimenta
- Faculdade de Motricidade Humana, CIPER, Universidade de Lisboa, Cruz Quebrada Dafundo, Lisboa, Portugal.
- Research Center of the Polytechnic Institute of Maia (N2i), Maia Polytechnic Institute (IPMAIA), Castêlo da Maia, 4475-690, Maia, Portugal.
- Futebol Clube Famalicão - Futebol SAD, Department of Rehabilitation and Performance, Famalicão, Portugal.
| | - Tomás Lopes
- Department of Biochemistry, King's College London, Oxford, UK
| | - A P Veloso
- Faculdade de Motricidade Humana, CIPER, Universidade de Lisboa, Cruz Quebrada Dafundo, Lisboa, Portugal
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Dutra YM, Lopes JPF, Murias JM, Zagatto AM. Within- and between-day reliability and repeatability of neuromuscular function assessment in females and males. J Appl Physiol (1985) 2023; 135:1372-1383. [PMID: 37916269 DOI: 10.1152/japplphysiol.00539.2023] [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: 08/03/2023] [Revised: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 11/03/2023] Open
Abstract
The study evaluated the reliability and repeatability of the force and surface electromyography activity (EMG) outcomes obtained through voluntary and electrically evoked contractions of knee extensors in females (n = 18) and males (n = 20) and compared these data between sexes. Maximal isometric voluntary contractions (iMVCs) of knee extensors associated with electrical stimulation of the femoral nerve were performed over 4 days (48-h interval), with the first day involving familiarization procedures, the second involving three trials (1-h interval), and the third and fourth involving just one trial. The intraclass correlation coefficient (ICC), coefficient of variation (CV), and repeatability of outcomes from within- and between-day trials were determined for each sex. Females presented lower maximal voluntary force during iMVC (iMVCForce) and associated vastus lateralis EMG activity (root mean square, RMSVL), force evoked by potentiated doublet high-frequency (Db100Force) and single stimuli (Qtw), and M-wave amplitude than males (P ≤ 0.01, partial eta squared ≥0.94). Voluntary activation (VA) and RMSVL/M-wave amplitude did not differ between sexes. iMVCForce, VA, Db100Force, Qtw, and M-wave amplitude were the most reliable outcomes in within-day trials, with similar results between sexes (ICC > 0.62; CV < 6.4%; repeatability: 12.2%-22.6%). When investigating between-day trials, the iMVCForce, VA, Db100Force, and Qtw were the most reliable (ICC > 0.66; CV < 7.5%; repeatability: 13.2%-33.45%) with similar results between sexes. In conclusion, females presented lower iMVCForce and evoked response than males. Although reliability and repeatability statistics vary between trials, data (e.g., from EMG or force signal), and sexes, most of the outcomes obtained through this technique are reliable in females and males.NEW & NOTEWORTHY Although reliability and repeatability of knee extensors vary according to the type of neuromuscular function outcome (e.g., from force or EMG responses), the trial intervals (i.e., hours or days), and the sex of the participant, most force and EMG outcomes obtained through these neuromuscular assessment protocols present ICC > 0.75, very good CV (<10%), and repeatability <25% in within- and between-day trials in both sexes.
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Affiliation(s)
- Yago Medeiros Dutra
- Department of Physical Education, Laboratory of Physiology and Sport Performance (LAFIDE), School of Sciences, São Paulo State University (UNESP), Bauru, Brazil
| | - João Pedro Fialho Lopes
- Department of Physical Education, Laboratory of Physiology and Sport Performance (LAFIDE), School of Sciences, São Paulo State University (UNESP), Bauru, Brazil
| | - Juan M Murias
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Alessandro Moura Zagatto
- Department of Physical Education, Laboratory of Physiology and Sport Performance (LAFIDE), School of Sciences, São Paulo State University (UNESP), Bauru, Brazil
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Obara K, Silva P, Silva M, Mendes F, Santiago G, Oliveira I, Cardoso J. Isokinetic Training Program to Improve the Physical Function and Muscular Performance of an Individual with Partial Injury of the Medial Meniscus: A Case Report. Int J Sports Phys Ther 2023; 18:758-768. [PMID: 37636894 PMCID: PMC10449488 DOI: 10.26603/001c.74945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 03/08/2023] [Indexed: 08/29/2023] Open
Abstract
Background and Purpose One of the best alternatives for the treatment of meniscal injuries in relation to surgical procedures, is exercise. This case report aimed to describe the effects of isokinetic training and a neuromuscular/proprioceptive exercise program on muscle performance and physical function in an individual after a rupture of the posterior horn of the medial meniscus. Study Design Case report. Case Description A 40-year-old man injured his right knee during a soccer match, with a partial lesion of the medial meniscus confirmed by magnetic resonance imaging. He completed an isokinetic training program in addition to exercises that targeted proprioception (22 sessions, 11 weeks) to improve physical function and performance, which were assessed before and after treatment and at a six-month follow-up. An individual with similar anthropometric characteristics was chosen to be used as a control for understanding the patient's assessment values. Outcomes Muscular performance of the knee flexors and extensors was evaluated isokinetically using the Biodex System-4 in a concentric mode at angular velocities of 60, 120, and 300 °/s . The main results indicated that after 11 weeks, the peak torque normalized to body mass (PT/BM), at 60 °/s of the knee extensors remained unchanged (2.54 N.m/kg) (below the control value - 3.06 N.m/kg), and at the six-month follow-up, increased by approximately 20% (3.08 N.m/kg). For the hamstrings, at 60 °/s, an increase of 18 % occurred after intervention (1.98 N.m/kg) and by approximately 30 % at the six-month follow-up (2.12 N.m/kg) - values much higher than the control 1.55 N.m/kg). This increase in the PT/BM was also reflected in the Hamstrings:Quadriceps ratio (78 %) after treatment which improved at follow-up (68 %). Discussion The results showed that the isokinetic training and neuromuscular/proprioceptive exercises improved the muscle performance of the knee flexors and extensors, after eleven weeks of intervention, and remained (or continued to improve) at the six-month follow-up. Level of evidence 5, single case report.
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Affiliation(s)
- Karen Obara
- Laboratory of Biomechanics and Clinical Epidemiology, PAIFIT Research Group Universidade Estadual de Londrina
| | - Pedro Silva
- Laboratory of Biomechanics and Clinical Epidemiology, PAIFIT Research Group Universidade Estadual de Londrina
| | - Mariana Silva
- Laboratory of Biomechanics and Clinical Epidemiology, PAIFIT Research Group Universidade Estadual de Londrina
| | - Fagner Mendes
- Laboratory of Biomechanics and Clinical Epidemiology, PAIFIT Research Group Universidade Estadual de Londrina
| | - Gabriel Santiago
- Laboratory of Biomechanics and Clinical Epidemiology, PAIFIT Research Group Universidade Estadual de Londrina
| | - Ihan Oliveira
- Laboratory of Biomechanics and Clinical Epidemiology, PAIFIT Research Group Universidade Estadual de Londrina
| | - Jefferson Cardoso
- Laboratory of Biomechanics and Clinical Epidemiology, PAIFIT Research Group Universidade Estadual de Londrina
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Performance fatigability during isometric vs. concentric quadriceps fatiguing tasks in men and women. J Electromyogr Kinesiol 2022; 67:102715. [PMID: 36274441 DOI: 10.1016/j.jelekin.2022.102715] [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: 07/01/2022] [Revised: 09/13/2022] [Accepted: 10/10/2022] [Indexed: 12/12/2022] Open
Abstract
In the present study, we aimed to provide a robust comparison of the fatigability of the knee extensors following isometric (ISO) and concentric (CON) tasks. Twenty young adults (25 ± 4 yr, 10 women) randomly performed the ISO and CON quadriceps intermittent fatigue test, consisting of ten (5 s on/5-s off, ISO) or one-hundred (0.5-s on/0.5-s off, CON) contractions with 10 % increments per stage until exhaustion. Performance fatigability was quantified as maximal isometric (MVIC) and concentric (MVCC) torque loss. Voluntary activation and contractile function (peak-twitch) were investigated using peripheral nerve stimulation. Number of stages (6.2 ± 0.7 vs. 4.9 ± 0.8; P < 0.001) and torque-time integral (20,166 ± 7,821 vs. 11,285 ± 4,933 Nm.s; P < 0.001) were greater for ISO than CON. MVIC, MVCC and voluntary activation decreased similarly between sessions (P > 0.05) whereas peak-twitch amplitude decreased more for CON (P < 0.001). The number of contractions was similar across sexes (ISO: men = 62 ± 8, women = 61 ± 5; CON: men = 521 ± 67, women = 458 ± 76, P > 0.05). MVCC was more reduced in women for both sessions (all P < 0.05), while MVIC loss was similar between sexes. We concluded that, despite greater torque-time integral and duration for ISO, both sessions induced a similar performance fatigability at exhaustion. Contractile function was more altered in CON. Finally, sex-related difference in fatigability depends on the contraction mode used during testing.
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Ha PL, Dalton BE, Alesi MG, Smith TM, VanDusseldorp TA, Feito Y, Hester GM. No sex differences in evoked contractile properties after fatiguing isometric and isotonic exercise for the plantar flexors. JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2022; 22:504-513. [PMID: 36458388 PMCID: PMC9716306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES Females tend to fatigue less than males after isometric exercise, but less is clear for isotonic exercise. Further, there have been relatively few sex comparisons for fatigability of the plantar flexors (PFs). We sought to investigate potential sex differences in contractile properties after a sustained maximal voluntary isometric contraction (MVIC) and isotonic contractions. METHODS Twenty-seven physically active males (n=14; 22±2 yrs) and females (n=13; 21±2 yrs) randomly performed a 2 min MVIC and 120 concentric isotonic (30% MVIC) contractions for the PFs on separate visits. Before and after each fatiguing task, muscle activation was obtained from brief MVICs, which was followed (~2 sec) by tibial nerve stimulation at rest. Contractile properties including peak twitch, absolute and normalized time to peak twitch, and half relaxation time were calculated. RESULTS No sex differences existed for fatigue-induced changes in muscle activation (p=0.09-0.41; d=0.33-0.69) or contractile properties (p=0.19-0.96; d=0.06-0.94). CONCLUSIONS Peripheral fatigue, as indicated by contractile parameters, did not differ between sexes after isometric or isotonic exercise. The PFs similar fiber type proportions between sexes or greater fiber type heterogeneity may explain why sex differences in fatigability, though common in other muscle groups (e.g., knee extensors), were not expressed in this muscle group.
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Affiliation(s)
- Phuong L. Ha
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA, USA
| | - Benjamin E. Dalton
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA, USA
| | - Michaela G. Alesi
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA, USA
| | - Tyler M. Smith
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA, USA
| | - Trisha A. VanDusseldorp
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA, USA;,Bonafide Health, LLC, Research and Development, Harrison, NY, USA
| | - Yuri Feito
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA, USA;,American College of Sports Medicine, Indianapolis, IN, USA
| | - Garrett M. Hester
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA, USA;,Corresponding author: Garrett M. Hester, Kennesaw State University, 520 Parliament Garden Way NW, Kennesaw, GA 30144, USA E-mail:
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