1
|
Hunter SK, S Angadi S, Bhargava A, Harper J, Hirschberg AL, D Levine B, L Moreau K, J Nokoff N, Stachenfeld NS, Bermon S. The Biological Basis of Sex Differences in Athletic Performance: Consensus Statement for the American College of Sports Medicine. Med Sci Sports Exerc 2023; 55:2328-2360. [PMID: 37772882 DOI: 10.1249/mss.0000000000003300] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
ABSTRACT Biological sex is a primary determinant of athletic performance because of fundamental sex differences in anatomy and physiology dictated by sex chromosomes and sex hormones. Adult men are typically stronger, more powerful, and faster than women of similar age and training status. Thus, for athletic events and sports relying on endurance, muscle strength, speed, and power, males typically outperform females by 10%-30% depending on the requirements of the event. These sex differences in performance emerge with the onset of puberty and coincide with the increase in endogenous sex steroid hormones, in particular testosterone in males, which increases 30-fold by adulthood, but remains low in females. The primary goal of this consensus statement is to provide the latest scientific knowledge and mechanisms for the sex differences in athletic performance. This review highlights the differences in anatomy and physiology between males and females that are primary determinants of the sex differences in athletic performance and in response to exercise training, and the role of sex steroid hormones (particularly testosterone and estradiol). We also identify historical and nonphysiological factors that influence the sex differences in performance. Finally, we identify gaps in the knowledge of sex differences in athletic performance and the underlying mechanisms, providing substantial opportunities for high-impact studies. A major step toward closing the knowledge gap is to include more and equitable numbers of women to that of men in mechanistic studies that determine any of the sex differences in response to an acute bout of exercise, exercise training, and athletic performance.
Collapse
Affiliation(s)
- Sandra K Hunter
- Exercise Science Program, Department of Physical Therapy, and Athletic and Human Performance Center, Marquette University, Milwaukee, WI
| | | | - Aditi Bhargava
- Department of Obstetrics and Gynecology, Center for Reproductive Sciences, University of California, San Francisco, CA
| | - Joanna Harper
- Loughborough University, Loughborough, UNITED KINGDOM
| | - Angelica Lindén Hirschberg
- Department of Women's and Children's Health, Karolinska Institutet, and Department of Gynecology and Reproductive Medicine, Karolinska University Hospital, Stockholm, SWEDEN
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and the Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Kerrie L Moreau
- Department of Medicine, Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, and Eastern Colorado Health Care System, Geriatric Research Education and Clinical Center, Aurora, CO
| | - Natalie J Nokoff
- Department of Pediatrics, Section of Endocrinology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Nina S Stachenfeld
- The John B. Pierce Laboratory and Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, CT
| | - Stéphane Bermon
- Health and Science Department, World Athletics, Monaco and the LAMHESS, University Côte d'Azur, Nice, FRANCE
| |
Collapse
|
2
|
James JJ, Klevenow EA, Atkinson MA, Vosters EE, Bueckers EP, Quinn ME, Kindy SL, Mason AP, Nelson SK, Rainwater KAH, Taylor PV, Zippel EP, Hunter SK. Underrepresentation of women in exercise science and physiology research is associated with authorship gender. J Appl Physiol (1985) 2023; 135:932-942. [PMID: 37650136 DOI: 10.1152/japplphysiol.00377.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/23/2023] [Accepted: 08/27/2023] [Indexed: 09/01/2023] Open
Abstract
Historically, low representation of women participants in exercise science and physiology studies has led to a lack of understanding in the response of women to exercise and therapeutic interventions. We hypothesized that 1) the number of women authors, participants, and editorial board members increased over 30 years (1991-2021) and 2) larger representation of women as editors and authors is associated with more women participants. Gender (man/woman) of editorial board members (n = 394), authors (n = 5,735), and participants (n = 2,984,883) of 972 original research articles with human participants published in 1991 and 2021 was analyzed from three journals: Journal of Applied Physiology, Medicine and Science in Sports and Exercise, and British Journal of Sports Medicine. Between 1991 to 2021, the average percent women per article as participants (21.9 ± 31.7% vs. 36.3 ± 30.3%, respectively, P < 0.001), authors (16.4 ± 22.4% vs. 30.9 ± 24.0%, P < 0.001), and editorial board members (13.3 ± 5.4% vs. 41.5 ± 7.3%, P = 0.006) increased. In 2021, the gender proportion of participants in large datasets was similar (50.2 ± 20.2% women). However, studies with smaller datasets (i.e., <∼3,000 participants) included less women (35.6 ± 30.6%). Women participants (%) were less when the last author was a man rather than a woman in 1991 (19.9 ± 29.5% vs. 34.3 ± 42.2%) and 2021 (31.6 ± 27.7% vs. 51.7 ± 33.4%). In 2021, there was a positive correlation between author and participant gender (% women) (r = 0.42, P < 0.001). Our data suggest that the low representation of women in exercise science and physiology research could be resolved with equitable numbers of women authors and editors and by encouraging men authors to study both women and men participants.NEW & NOTEWORTHY Analysis of human applied physiology studies revealed that the representation of women authors, participants, and editorial board members increased over 30 years but remained lower than men in 2021. Larger representation of women editors and authors was associated with more women participants. Women authors assessed similar numbers of women and men participants, whereas men authors included less women. Equitable representation of women participants may be achieved by closing the gender gap in authorship and editorial board membership.
Collapse
Affiliation(s)
- Jessica J James
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, United States
| | - Emilie A Klevenow
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, United States
| | - Mira A Atkinson
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, United States
| | - Emma E Vosters
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, United States
| | - Elizabeth P Bueckers
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, United States
| | - Meagan E Quinn
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, United States
| | - Samantha L Kindy
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, United States
| | - Azara P Mason
- University School of Milwaukee, River Hills, Wisconsin, United States
| | | | | | | | | | - Sandra K Hunter
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, United States
| |
Collapse
|
3
|
O'Halloran KD. Potentiated respiratory metaboreflex in older males and females: afferent or efferent mechanisms? J Physiol 2023; 601:393-394. [PMID: 36632665 DOI: 10.1113/jp284167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/13/2023] Open
Affiliation(s)
- Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| |
Collapse
|
4
|
Islam H, Gillen JB. Skeletal muscle mechanisms contributing to improved glycemic control following intense interval exercise and training. SPORTS MEDICINE AND HEALTH SCIENCE 2023; 5:20-28. [PMID: 36994179 PMCID: PMC10040385 DOI: 10.1016/j.smhs.2023.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/07/2023] [Accepted: 01/11/2023] [Indexed: 01/26/2023] Open
Abstract
High-intensity and sprint interval training (HIIT and SIT, respectively) enhance insulin sensitivity and glycemic control in both healthy adults and those with cardiometabolic diseases. The beneficial effects of intense interval training on glycemic control include both improvements seen in the hours to days following a single session of HIIT/SIT and those which accrue with chronic training. Skeletal muscle is the largest site of insulin-stimulated glucose uptake and plays an integral role in the beneficial effects of exercise on glycemic control. Here we summarize the skeletal muscle responses that contribute to improved glycemic control during and following a single session of interval exercise and evaluate the relationship between skeletal muscle remodelling and improved insulin sensitivity following HIIT/SIT training interventions. Recent evidence suggests that targeting skeletal muscle mechanisms via nutritional interventions around exercise, particularly with carbohydrate manipulation, can enhance the acute glycemic benefits of HIIT. There is also some evidence of sex-based differences in the glycemic benefits of intense interval exercise, with blunted responses observed after training in females relative to males. Differences in skeletal muscle metabolism between males and females may contribute to sex differences in insulin sensitivity following HIIT/SIT, but well-controlled studies evaluating purported muscle mechanisms alongside measurement of insulin sensitivity are needed. Given the greater representation of males in muscle physiology literature, there is also a need for more research involving female-only cohorts to enhance our basic understanding of how intense interval training influences muscle insulin sensitivity in females across the lifespan.
Collapse
|
5
|
Skelly LE, Bailleul C, Gillen JB. Physiological Responses to Low-Volume Interval Training in Women. SPORTS MEDICINE - OPEN 2021; 7:99. [PMID: 34940959 PMCID: PMC8702506 DOI: 10.1186/s40798-021-00390-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/26/2021] [Indexed: 12/11/2022]
Abstract
Interval training is a form of exercise that involves intermittent bouts of relatively intense effort interspersed with periods of rest or lower-intensity exercise for recovery. Low-volume high-intensity interval training (HIIT) and sprint interval training (SIT) induce physiological and health-related adaptations comparable to traditional moderate-intensity continuous training (MICT) in healthy adults and those with chronic disease despite a lower time commitment. However, most studies within the field have been conducted in men, with a relatively limited number of studies conducted in women cohorts across the lifespan. This review summarizes our understanding of physiological responses to low-volume interval training in women, including those with overweight/obesity or type 2 diabetes, with a focus on cardiorespiratory fitness, glycemic control, and skeletal muscle mitochondrial content. We also describe emerging evidence demonstrating similarities and differences in the adaptive response between women and men. Collectively, HIIT and SIT have consistently been demonstrated to improve cardiorespiratory fitness in women, and most sex-based comparisons demonstrate similar improvements in men and women. However, research examining insulin sensitivity and skeletal muscle mitochondrial responses to HIIT and SIT in women is limited and conflicting, with some evidence of blunted improvements in women relative to men. There is a need for additional research that examines physiological adaptations to low-volume interval training in women across the lifespan, including studies that directly compare responses to MICT, evaluate potential mechanisms, and/or assess the influence of sex on the adaptive response. Future work in this area will strengthen the evidence-base for physical activity recommendations in women.
Collapse
|
6
|
Alexander SE, Abbott G, Aisbett B, Wadley GD, Hnatiuk JA, Lamon S. Total testosterone is not associated with lean mass or handgrip strength in pre-menopausal females. Sci Rep 2021; 11:10226. [PMID: 33986323 PMCID: PMC8119405 DOI: 10.1038/s41598-021-89232-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 04/21/2021] [Indexed: 12/02/2022] Open
Abstract
The aim of this study was to examine the relationship between endogenous testosterone concentrations and lean mass and handgrip strength in healthy, pre-menopausal females. Testosterone has been positively associated with lean mass and strength in young and older males. Whether this relationship exists in pre-menopausal females is unknown. Secondary data from the 2013-2014 National Health and Nutrition Examination Survey were used to test this relationship. Females were aged 18-40 (n = 716, age 30 ± 6 years, mean ± SD) and pre-menopausal. Multivariate linear regression models were used to examine associations between total testosterone, lean mass index (LMI) and handgrip strength. Mean ± SD testosterone concentration was 1.0 ± 0.6 nmol L-1 and mean free androgen index (FAI) was 0.02 ± 0.02. In pre-menopausal females, testosterone was not associated with LMI (β = 0.05; 95%CI - 0.04, 0.15; p = 0.237) or handgrip strength (β = 0.01; 95%CI - 0.11, 0.12; p = 0.926) in a statistically significant manner. Conversely, FAI was associated with LMI (β = - 0.03; 95%CI - 0.05, - 0.02; p = 0.000) in a quadratic manner, meaning LMI increases with increasing FAI levels. Handgrip strength was not associated with FAI (β = 0.06; 95%CI - 0.02, 0.15; p = 0.137). These findings indicate that FAI, but not total testosterone, is associated with LMI in pre-menopausal females. Neither FAI nor total testosterone are associated with handgrip strength in pre-menopausal females when testosterone concentrations are not altered pharmacologically.
Collapse
Affiliation(s)
- Sarah E Alexander
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Gavin Abbott
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Brad Aisbett
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Glenn D Wadley
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Jill A Hnatiuk
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Séverine Lamon
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia.
| |
Collapse
|
7
|
Saunders B, Oliveira LFD, Dolan E, Durkalec-Michalski K, McNaughton L, Artioli GG, Swinton PA. Sodium bicarbonate supplementation and the female athlete: A brief commentary with small scale systematic review and meta-analysis. Eur J Sport Sci 2021; 22:745-754. [PMID: 33487131 DOI: 10.1080/17461391.2021.1880649] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Sodium bicarbonate (SB) is considered an effective ergogenic supplement for improving high-intensity exercise capacity and performance, although recent data suggests that women may be less amenable to its ergogenic effects than men. Currently, an apparent paucity of data on women means no consensus exists on whether women benefit from SB supplementation. The aim of the current study was to quantify the proportion of the published literature on SB supplementation that includes women, and to synthesise the evidence regarding its effects on blood bicarbonate and exercise performance in women by performing a systematic review and meta-analysis. Electronic searches of the literature were undertaken using three databases (MEDLINE, Embase, SPORTDiscus) to identify relevant articles. All meta-analyses were performed within a Bayesian framework. A total of 149 SB articles were identified, 11 of which contained individual group data for women. Results indicated a pooled blood bicarbonate increase of 7.4 [95%CrI: 4.2-10.4 mmol·L-1] following supplementation and a pooled standardised exercise effect size of 0.37 [95%CrI: -0.06-0.92]. The SB literature is skewed, with only 20% (30 studies) of studies employing female participants, of which only 11 studies (7.4%) provided group analyses exclusively in women. Despite the small amount of available data, results are consistent in showing that SB supplementation in women leads to large changes in blood bicarbonate and that there is strong evidence for a positive ergogenic effect on exercise performance that is likely to be small to medium in magnitude.Highlights This study aimed to quantify the proportion of the published literature on sodium bicarbonate supplementation that includes women and to synthesise the evidence regarding its ergogenic effect on women, using a systematic review and meta-analytic approach.The sodium bicarbonate literature is skewed, with only 30 studies (20%) employing female participants, of which only 11 studies (7.4%) provided group analyses exclusively in women.Despite the small amount of available data, results are consistent in showing that sodium bicarbonate supplementation in women leads to large changes in blood bicarbonate and that there is strong evidence for a positive ergogenic effect on exercise performance that is likely small to medium in magnitude.Based on these findings, we do not believe there is any evidence to support sex-specific sodium bicarbonate dosing recommendations and that current recommendations of 0.2-0.3 g·kg-1BM of SB taken 60-180 min prior to high-intensity exercise appear appropriate for the female athlete.
Collapse
Affiliation(s)
- Bryan Saunders
- Applied Physiology & Nutrition Research Group, Rheumatology Division, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, Brazil.,Institute of Orthopaedics and Traumatology, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, Brazil.,Department of Dietetics, Poznań University of Physical Education, Poznań, Poland
| | - Luana Farias de Oliveira
- Applied Physiology & Nutrition Research Group, Rheumatology Division, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, Brazil
| | - Eimear Dolan
- Applied Physiology & Nutrition Research Group, Rheumatology Division, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, Brazil
| | - Krzysztof Durkalec-Michalski
- Department of Dietetics, Poznań University of Physical Education, Poznań, Poland.,Department of Human Nutrition and Dietetics, Poznań University of Life Sciences, Poznań, Poland
| | - Lars McNaughton
- Sports Nutrition and Performance Group, Department of Sport and Physical Activity, Edge Hill University, Ormskirk, UK
| | - Guilherme Giannini Artioli
- Applied Physiology & Nutrition Research Group, Rheumatology Division, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, Brazil
| | | |
Collapse
|
8
|
Piasecki J, Inns TB, Bass JJ, Scott R, Stashuk DW, Phillips BE, Atherton PJ, Piasecki M. Influence of sex on the age-related adaptations of neuromuscular function and motor unit properties in elite masters athletes. J Physiol 2021; 599:193-205. [PMID: 33006148 DOI: 10.1113/jp280679] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/24/2020] [Indexed: 12/30/2022] Open
Abstract
KEY POINTS Masters athletes maintain high levels of activity into older age and allow an examination of the effects of aging dissociated from the effects of increased sedentary behaviour. Evidence suggests masters athletes are more successful at motor unit remodelling, the reinnervation of denervated fibres acting to preserve muscle fibre number, but little data are available in females. Here we used intramuscular electromyography to demonstrate that motor units sampled from the tibialis anterior show indications of remodelling from middle into older age and which does not differ between males and females. The age-related trajectory of motor unit discharge characteristic differs according to sex, with female athletes progressing to a slower firing pattern that was not observed in males. Our findings indicate motor unit remodelling from middle to older age occurs to a similar extent in male and female athletes, with discharge rates progressively slowing in females only. ABSTRACT Motor unit (MU) remodelling acts to minimise loss of muscle fibres following denervation in older age, which may be more successful in masters athletes. Evidence suggests performance and neuromuscular function decline with age in this population, although the majority of studies have focused on males, with little available data on female athletes. Functional assessments of strength, balance and motor control were performed in 30 masters athletes (16 male) aged 44-83 years. Intramuscular needle electrodes were used to sample individual motor unit potentials (MUPs) and near-fibre MUPs in the tibialis anterior (TA) during isometric contractions at 25% maximum voluntary contraction, and used to determine discharge characteristics (firing rate, variability) and biomarkers of peripheral MU remodelling (MUP size, complexity, stability). Multilevel mixed-effects linear regression models examined effects of age and sex. All aspects of neuromuscular function deteriorated with age (P < 0.05) with no age × sex interactions, although males were stronger (P < 0.001). Indicators of MU remodelling also progressively increased with age to a similar extent in both sexes (P < 0.05), whilst MU firing rate progressively decreased with age in females (p = 0.029), with a non-significant increase in males (p = 0.092). Masters athletes exhibit age-related declines in neuromuscular function that are largely equal across males and females. Notably, they also display features of MU remodelling with advancing age, probably acting to reduce muscle fibre loss. The age trajectory of MU firing rate assessed at a single contraction level differed between sexes, which may reflect a greater tendency for females to develop a slower muscle phenotype.
Collapse
Affiliation(s)
- Jessica Piasecki
- Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Thomas B Inns
- Clinical, Metabolic and Molecular Physiology, MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
| | - Joseph J Bass
- Clinical, Metabolic and Molecular Physiology, MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
| | - Reece Scott
- Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Daniel W Stashuk
- Department of Systems Design Engineering, University of Waterloo, Ontario, Canada
| | - Bethan E Phillips
- Clinical, Metabolic and Molecular Physiology, MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
| | - Philip J Atherton
- Clinical, Metabolic and Molecular Physiology, MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
| | - Mathew Piasecki
- Clinical, Metabolic and Molecular Physiology, MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
| |
Collapse
|