Female physiology–endocrinology: education is lacking and innovation is needed!

Throughout their lifespans, women undergo unique endocrinological changes relative to their reproductive hormones. The influence of how the female sex steroid hormones have nonreproductive actions is a trending topic of great interest in the exercise–sports sciences, especially among women of reproductive age. Herein, we present several key points on our perspective for moving the study of this topic forward in the future. These are (a) encouraging researchers to pursue high-quality research on female physiology–endocrinology in the exercise–sports science setting, (b) the need for exercise–sports science educational curriculums at the university level to embrace the study of female physiology–endocrinology area, and (c) the need for innovation in the study of this topic. As such, we propose using research design models involving supraphysiological hormonal states in vivo, that is, pregnancy and in vitro fertilization treatment, to gain new insights on sex steroid hormonal actions in women. Herein, we provide the rationale for our recommendations as well as a brief physiological overview of these clinical states. We acknowledge, exercise sports sciences need more studies on women! But there is a need to “think outside the box” on this topic, and we encourage researchers to be unconventional, be bold, think creatively, and contemplate whether these supraphysiological hormonal states might give them insightful information on female physiology and ovarian sex steroid hormones actions

Experiences of physical activity, healthy eating and quality of life during and following pregnancy in overweight and obese postpartum women

Objectives This retrospective study explored the experiences of women with overweight or obesity regarding physical activity, diet and quality of life leading up to, during, and following pregnancy. Methods A qualitative descriptive design was adopted, whereby data collected through semi-structured interviews were analysed using thematic analysis. Throughout the interviews, individuals were asked to describe their barriers to a healthy lifestyle during and following pregnancy. Results Ten women (34.5 ± 5.2 years old, BMI 30.4 ± 3.5 kg·m− 2) who were between 12 and 52 weeks postpartum participated. A range of themes were identified when discussing barriers to physical activity and healthy eating during and following pregnancy. For example, tiredness, especially in the third trimester of pregnancy, and a lack of support at home, was often cited as preventing engagement in exercise and healthy eating practices. A lack of convenience when attending exercise classes, medical complications following the birth and the cost of attending pregnancy-specific classes were identified as barriers to exercise engagement. Cravings and nausea were identified as barriers to healthy eating during pregnancy. Quality of life was positively associated with exercise and healthy eating, whilst a lack of sleep, loneliness and a loss of freedom since the baby had arrived negatively influenced quality of life. Discussion Postpartum women with overweight and obesity experience many barriers when attempting to engage in a healthy lifestyle during and following pregnancy. These findings can be used to inform the design and delivery of future lifestyle interventions in this population. Significance What is Already Known on this Subject? Pregnant and postpartum women experience a multitude of barriers when attempting to engage in a healthy lifestyle. What this Study adds? Until now, investigations into barriers to participation in a healthy lifestyle in overweight and obese pregnant and postpartum women have been lacking. Akin to normal weight women, women with a BMI > 25 kg/m2 experience many barriers to a healthy lifestyle during and following pregnancy. In this exclusive overweight and obese population, medical complications was the most cited barrier to postpartum exercise engagement. These results will be considered when designing future postpartum lifestyle interventions

Carnosine increases insulin-stimulated glucose uptake and reduces methylglyoxal-modified proteins in type-2 diabetic human skeletal muscle cells

Type-2 diabetes (T2D) is characterised by a dysregulation of metabolism, including skeletal muscle insulin resistance, mitochondrial dysfunction, and oxidative stress. Reactive species, such as methylglyoxal (MGO) and 4-hydroxynonenal (4-HNE), positively associate with T2D disease severity and can directly interfere with insulin signalling and glucose uptake in skeletal muscle by modifying cellular proteins. The multifunctional dipeptide carnosine, and its rate-limiting precursor β-alanine, have recently been shown to improve glycaemic control in humans and rodents with diabetes. However, the precise mechanisms are unclear and research in human skeletal muscle is limited. Herein, we present novel findings in primary human T2D and lean healthy control (LHC) skeletal muscle cells. Cells were differentiated to myotubes, and treated with 10 mM carnosine, 10 mM β-alanine, or control for 4-days. T2D cells had reduced ATP-linked and maximal respiration compared with LHC cells (p = 0.016 and p = 0.005). Treatment with 10 mM carnosine significantly increased insulin-stimulated glucose uptake in T2D cells (p = 0.047); with no effect in LHC cells. Insulin-stimulation increased MGO-modified proteins in T2D cells by 47%; treatment with carnosine attenuated this increase to 9.7% (p = 0.011). There was no effect treatment on cell viability or expression of other proteins. These findings suggest that the beneficial effects of carnosine on glycaemic control may be explained by its scavenging actions in human skeletal muscle

P1NP and β-CTX-1 responses to a prolonged, continuous running bout in young healthy adult males: a systematic review with individual participant data meta-analysis.

Circulating biomarkers of bone formation and resorption are widely used in exercise metabolism research, but their responses to exercise are not clear. To quantify group responses and inter-individual variability of P1NP and β-CTX-1 after prolonged, continuous running (60-120 min at 65-75% VO2max) in young healthy adult males using individual participant data (IPD) meta-analysis. The protocol was designed following PRISMA-IPD guidelines. Changes in P1NP and β-CTX-1 relative to baseline were measured during, immediately after, and in the hours and days following exercise. Typical hourly and daily variations were estimated from P1NP and β-CTX-1 changes relative to baseline in non-exercise (control) conditions. Group responses and inter-individual variability were quantified with estimates of the mean and standard deviation of the difference, and the proportion of participants exhibiting an increased response. Models were conducted within a Bayesian framework with random intercepts to account for systematic variation across studies. P1NP levels increased during and immediately after running, where the proportion of response was close to 100% (75% CrI: 99 to 100%). P1NP levels returned to baseline levels within 1 hour and over the next 4 days, showing comparable mean and standard deviation of the difference with typical hourly (0.1 ± 7.6 ng·ml-1) and daily (-0.4 ± 5.7 ng·ml-1) variation values. β-CTX-1 levels decreased during and up to 4 hours after running with distributions comparable to typical hourly variation (-0.13 ± 0.11 ng·ml-1). There was no evidence of changes in β-CTX-1 levels during the 4 days after the running bout, where distributions were also similar between the running data and typical daily variation and (-0.03 ± 0.10 ng·ml-1). Transient increases in P1NP were likely biological artefacts (e.g., connective tissue leakage) and not reflective of bone formation. Comparable small decreases in β-CTX-1 identified in both control and running data, suggested that these changes were due to the markers' circadian rhythm and not the running intervention. Hence, prolonged continuous treadmill running did not elicit bone responses, as determined by P1NP and β-CTX-1, in this population. The protocol for this review was pre-registered on the Open Science Framework prior to implementation (https://osf.io/y69nd)

Feminae: an international multi-site innovative project for female athletes.

Sufficient high-quality studies in sport science using women as participants are lacking, meaning that our knowledge and understanding of female athletes in relation to their ovarian hormone profiles is limited. Consortia can be used to pool talent, expertise, and data, thus accelerating our learning on a given topic and reducing research waste through collaboration. To this end, we have assembled an international multi-site team, described herein, to investigate the effects of the menstrual cycle and oral contraceptive pill phase on aspects of exercise physiology and sports performance in female athletes. We intend to produce an adequately powered, high-quality dataset which can be used to inform the practices of female athletes. Our approach will also employ research transparency – through the inclusion of a process evaluation - and reproducibility – through a standardised study protocol

The legacy of pregnancy: elite athletes and women in arduous occupations

Best-practice guidance and management of pregnant and postpartum elite athletes and women in arduous occupations is limited by the lack of high-quality evidence available within these populations. We have summarized the adaptations and implications of pregnancy and childbirth, proposed a novel integrative concept to address these changes, and made recommendations to progress research in this area

Current evidence shows no influence of women's menstrual cycle phase on acute strength performance or adaptations to resistance exercise training

Introduction: The bias towards excluding women from exercise science research is often due to the assumption that cyclical fluctuations in reproductive hormones influence resistance exercise performance and exercise-induced adaptations. Methods: Hence, the purpose of this umbrella review was to examine and critically evaluate the evidence from meta-analyses and systematic reviews on the influence of menstrual cycle phase on acute performance and chronic adaptations to resistance exercise training (RET). Results: We observed highly variable findings among the published reviews on the ostensible effects of female sex hormones on relevant RET-induced outcomes, including strength, exercise performance, and hypertrophy. Discussion: We highlight the importance of comprehensive menstrual cycle verification methods, as we noted a pattern of poor and inconsistent methodological practices in the literature. In our opinion, it is premature to conclude that short-term fluctuations in reproductive hormones appreciably influence acute exercise performance or longer-term strength or hypertrophic adaptations to RET

Weight loss practices and eating behaviours among female physique athletes: Acquiring the optimal body composition for competition

From PLOS via Jisc Publications RouterHistory: received 2021-05-14, accepted 2021-12-28, collection 2022, epub 2022-01-14Publication status: PublishedLittle is known about weight loss practices and eating behaviours in female physique athletes. This study investigated the weight loss history, practices, and key influences during the pre-competition period in a large cohort of female physique athletes stratified by division and experience level. Eating attitudes and behaviours were assessed to identify whether athletes were at risk of developing an eating disorder. Using a cross-sectional research design, female physique athletes (n = 158) were recruited and completed an anonymous online self-reported survey consisting of two validated questionnaires: Rapid Weight Loss Questionnaire and Eating Attitudes Test-26. Irrespective of division or experience, female physique athletes used a combination of weight loss practices during the pre-competition phase. Gradual dieting (94%), food restriction (64%) and excessive exercise (84%), followed by body water manipulation via water loading (73%) were the most commonly used methods. Overall, 37% of female physique athletes were considered at risk of developing an eating disorder. Additionally, 42% of female physique athletes used two pathogenic weight control methods with 34% of Figure novice athletes indicating binge eating once a week or more. The coach (89%) and another athlete (73%) were identified as key influences on athletes’ dieting practices and weight loss. The prevalence of athletes identified with disordered eating symptoms and engaging in pathogenic weight control methods is concerning. In future, female physique athletes should seek advice from registered nutritionists to optimise weight management practices and minimise the risk of developing an eating disorder

Where do you go when your periods go?: A case-study examining secondary amenorrhea in a professional internationally-capped female soccer player through the lens of the sport nutritionist

This case study follows a professional internationally capped female soccer player's two-year journey from eumenorrhea, through injury, to amenorrhea, and the challenges faced by the player and nutritionist. The two years are split into three sections: (1) longitudinal profiling of the player, (2) nutrition to support her return from injury, and (3) investigation into the observed secondary amenorrhea. The cause of amenorrhea was investigated through the assessment of energy availability via doubly labelled water, remote food photography, blood biomarkers and resting metabolic rate. Despite having secondary amenorrhea and anovulatory cycles, the player did not have low energy availability. This study shows the importance for practitioner's, particularly nutritionists, to not assume that all menstrual irregularities are caused by low energy availability and could be caused by a combination of factors (e.g. clinical, physiological, and psychological), which requires a multi-disciplinary investigation and intervention team. This study also showed that education needs to be provided about menstrual health to elite female soccer players as the player (i) believed that not having a period was beneficial for performance and unsure of possible health implications; (ii) was convinced that a one-day bleed indicated a regular menstrual cycle; and (iii) was reluctant to waste the practitioners time discussing menstrual issues and was nervous of finding out if she had an actual health issue. It is therefore crucial that players feel comfortable in discussing their menstrual status with practitioners to support their performance and long-term health

Oral contraceptive use in Premiership and Championship women's rugby union: perceived symptomology, management strategies, and performance and wellness effects

The aim of this study was to investigate the prevalence of oral contraceptive use in domestic rugby union, to compare symptomology by contraceptive use, and to determine symptom management strategies. Additionally, to characterise the perceived influence of oral contraceptive use and non-use on wellness and performance. A total of 238 Premiership and Championship women's rugby union players completed an online questionnaire. The survey was comprised of questions relating to player characteristics, hormonal or non-hormonal contraceptive characteristics, perceived symptomology, symptom management strategies, and performance and wellness characteristics. The prevalence of oral contraceptive users was 26%. Non-hormonal contraceptive users reported greater perceived negative symptomology (i.e., back pain, nausea, sore breasts) and performance and wellness effects (i.e., fatigue, stress, mood, concentration, power, match-play) than oral contraceptive users. The most common symptom management strategies were medication (33%), nutritional interventions (20%), and training modulation (20%). Twelve percent of players had previously spoken to staff about their menstrual cycle (i.e., regular and irregular) or contraceptive use. The most common barriers to speaking to staff were 'male staff' (29%) and 'club culture' (24%). The importance of assisting non-hormonal contraceptive users in managing symptoms is evident. Emphasis on overcoming barriers to staff-player dialogue regarding menstrual/contraceptive cycle is required