Gender and Sex Science in Athletics

Benefits

“junior competitive weightlifters have an increased bone mineral content (BMC), well above the age-matched controls’ mean.”

“intensive tennis playing led to a significant increase in the BMD and BMC of the playing extremity.”

“periodized progressive strength/ resistance training was associated with continued significant improvements in high-intensity physical performance, and adaptations in strength, power, and endurance were specific to the subtle differences in the resistance training programs.”

“climbers exhibited slower breathing frequency, larger tidal volume and larger muscle oxygenation index.”

“these results suggest that elite climbers show some specific ventilatory and muscular responses to hypoxia possibly because of genetic factors or adaptation to frequent high-altitude climbing.”

Sex differences

This article presents the sex-related differences and specific physical characteristics of weightlifters: “to reduce the typical sex-related difference in the expression of neuromuscular strength and power.”

“greater body fat content, less muscle mass, endomorphic (large effect) than men”, all of which are: “all key anthropometrical characteristics required to excel in endurance events.”

“male water skiers were lower in endomorphic component and better in power, speed, and cardiorespiratory fitness than female water skiers.”

“an alarming doping susceptibility in youth swimmers among youth age swimmers.”

The results showed that: “the associations between the coaching strategies and training methodologies CS&TM variables and potential doping behavior in junior swimmers were nonsignificant… A lower susceptibility to doping in girls who were more successful, and, a greater potential doping behavior to doping PDB in girls who initiated an intensive training regimen at a younger age.”

“boys who had better knowledge about nutrition and dietary supplementation were less prone to doping.”

“Our results indicated that 71% of swimmers had a negative doping tendency. In previous studies where authors used the same measurement tools, a lower tendency toward PDB was found in sailing athletes (82%) and tennis players (75%), and a somewhat higher tendency was found in team sport athletes and synchronized swimmers (approximately 62–63% with negative PDB). Conversely, a much higher likelihood of doping has been reported for weightlifters, kickboxers, and rugby players (30%, 45%, and 51.4% negative PDB, respectively). The results of the doping tendency of youth swimmers in the present study are comparable to previous studies, where authors reported similar values for adult swimmers (>18 years): approximately 80% of swimmers had a negative tendency toward doping. Altogether, these results place swimming among the sports with a high risk of doping behavior, which is directly supported by 2016 WADA reports of positive analytical findings…”

Musculoskeletal

“the different capacity of the sexes with respect to strength is rooted in the differently dimensioned cross sections of the muscle fibres and in the higher activation capability of the skeletal muscles of men.”

“no differences exist with respect to the relative proportions of the ST-, FTa- and FTb-fibres and with respect to the biochemistry of the muscles… It is true, that women have a smaller heart volume and lower values for the maximum oxygen uptake, but these differences or by no means related to sex alone.”

“as regards the energy substrates, there is the hypothesis that women have better utilization of free fatty acids under conditions of prolonged and intensive physical work.”

“Men had larger (p<0.01) total and regional SM mass than women.”

Cardiovascular System

“lower hemoglobin concentration in both males and females after 12 wk of weight training and reduced iron stores after 8 wk in males with initially adequate iron levels.”

“both cardiovascular and muscular functions were improved as were blood lipid profiles, and small, positive but significant changes in body composition were also observed in response to 9 weeks of endurance and strength training sessions.”

Nervous System

“In the post-exercise period, females display lower thermolytic capacities than males. Therefore, the use of cooling recovery methods following exercise, such as cold water immersion or the use of a cooling vest, appear particularly beneficial for female athletes. In addition, a greater decrease in arterial blood pressure is observed after exercise in females than in males. Given that the return to homeostasis after a brief intense exercise appears linked to maintaining good venous return, it is conceivable that female athletes would find a greater advantage to active recovery modes than males.This article reviews some of the major sex differences in the metabolic, inflammatory and thermoregulatory response to exercise and its subsequent recovery.”

Athletic Skills

“the results of this study demonstrate that (a) power and running speed are more significantly related to agility manifestations among female collegiate athletes than among their male peers, whereas (b) balance is found to be important predictor of the agility measures among men but not among women.”

“men attained peak power in a significantly shorter time than the women; the power decrease was also significantly quicker with time in the men’s group, while “the time of maintaining power was similar in both groups.”

Body weight

“disordered eating, iron deficiency anemia, amenorrhea, premature osteoporosis, and injuries.”

** also in Youth

Menstrual Cycle

“maintaining a positive iron balance is essential for female athletes to avoid the effects of iron deficiency and anemia and to maintain or improve performance… Menstruating females, particularly those with heavy menstrual bleeding are at an elevated risk of iron deficiency.”

Additionally, “a more detailed and longitudinal examination of hematology, menstrual cycle pattern, biochemistry, exercise physiology, environmental factors and training load can offer a superior characterisation of iron status and help to direct appropriate interventions that will avoid iron deficiency or iron overload.”

“The female athlete should be encouraged to give special attention to two nutrients, water and iron. Any female athlete participating in physical activity causing significant sweat loss should understand the importance of fluid balance and how to properly rehydrate during and following exercise.”

Education

“The nutrients required for physically active women are the same as for women in the general population and for men… In general, female athletes will need more energy, water, sodium, potassium, and certain vitamins (thiamin, riboflavin, niacin) than nonathletic females.”

“lack of nutrition knowledge has been observed at the high school level and may be attributed to the sources to which athletes look for nutrition guidance.”

“understanding the content of nutrition is important for student athletes to improve their overall nutrition and athletic performance: “knowledge of protein needs, vitamin and mineral needs, and fluid needs has been shown to be lacking among athletes.”

“If nurses are knowledgeable about sports nutrition and have a support network for nutrition information, they can help young athletes understand their sports nutrition needs.”

“studies give an inappropriate evaluation of the prevalence of adequacy/inadequacy of micronutrient intake among endurance athletes.”

“there is a need for a comprehensive and well-conducted nutrition assessment planning to fulfill the existing gap in reliable information about micronutrient adequacy of endurance athletes.”

“this review provides a practical overview of key physiological and nutritional considerations for the active female.”

“the majority of dietary supplements have been evaluated primarily in men; based on physiological theory and sex-physiology, the following sections introduce potential dietary supplements that may be efficacious for women.”

“It has been shown that females require more lysine during the luteal phase than the follicular phase.”

Sex differences

“some gender differences were noted such as sports being a predominant facilitator in choosing to consume dairy in males only and eating out as a facilitator or barrier to dairy product consumption depending on gender.”

“significant differences for the type of nutritional supplements NS consumed between gender and age groups and the number of weekly training hours.”

“athletes sought advice on supplementation mainly from physicians (56 %) and coaches (46 %). Age and gender were found to influence reasons for use and the source of information.”

Male hormones

“we observed a positive correlation between endogenous testosterone level and stronger muscle strength and better physical performance.”

“Appendicular skeletal mass (ASM) was positively associated with total testosterone (TT; P<0.001), free testosterone (FT; P<0.001), and total E2 (P<0.001) but not with free E2 (P=0.102). After adjustment for age, serum SHBG and relative ASM, both TT and FT were significantly associated with grip strength, narrow-walk speed and the composite neuromuscular score. Higher total E2, but not free E2 was associated with lower grip strength (P<0.05) after adjustment for age, FT, SHBG and relative ASM… Testosterone level was related to both muscle mass, strength and physical performance. Total E2 level, though related to muscle mass positively, affected muscle strength adversely in older men.”

Female hormones

“estradiol, progesterone, and testosterone each contribute to changes in knee laxity across the cycle, and that this relationship is stronger when changes in hormone concentrations are compared with changes in knee laxity occurring approximately 3–4 d later. However, the variable time shifts between subjects and the substantially greater variance explained by the regression model for each individual subject compared with the group analysis suggests this relationship is quite variable between subjects.”

Both female and male hormones

“The results from published studies reviewed show clearly that the range for testosterone levels in healthy males is distinct from that for healthy females… The weighted average lower limit of testosterone level in healthy males is 8.8 nmol/L (254 ng/dL), roughly four- to fivefold higher than the average upper limit of the testosterone level in healthy females, 2.0 nmol/L (58 ng/dL).”

“Individuals with 46XY DSD, specifically those with 5-alpha reductase deficiency, type 2 and androgen insensitivity syndrome testosterone levels that were within normal male range. Females with PCOS or congenital adrenal hyperplasia were above the normal female range but still below the normal male range.”

“In men, there is unequivocal evidence that hCG and estrogen blockers cause consistent and sustained rise in blood testosterone concentrations. In women, although there has been no direct testing of ergogenic or myotrophic properties of exogenous testosterone in healthy women, either hCG or estrogen blockers do not produce any consistent or biologically significant increase in blood testosterone concentrations.”

“there is no convincing evidence that either hCG or estrogen blockers (antiestrogens, SERMs, aromatase inhibitors) cause any consistent or biologically significant increase blood testosterone concentrations in women. In the absence of direct testing of ergogenic or myotrophic properties, blood testosterone is a reasonable surrogate maker, suggesting that drug-induced performance enhancement is most unlikely.”

“AAS in supratherapeutic doses may increase muscular strength and lean body mass in athletes, whereas endurance performance and fat mass appear to be unaffected. Because of the widespread use of large doses of AAS, the adverse effects are of great concern.”

“based on the non overlapping, bimodal distribution of circulating testosterone concentration (measured by liquid chromatography–mass spectrometry)—and making an allowance for women with mild hyperandrogenism, notably women with polycystic ovary syndrome (who are overrepresented in elite athletics)—the appropriate eligibility criterion for female athletic events should be a circulating testosterone of <5.0 nmol/L. This would include all women other than those with untreated hyperandrogenic disorders of sexual development and noncompliant male-to-female transgender as well as testosterone-treated female-to-male transgender or androgen dopers.”

“There is strong evidence that AAS causes reversible suppression of endogenous sex steroid hormone production, marked decreases in serum HDL cholesterol, and decreased fertility in men and women. In addition, AASs are known to increase erythropoiesis and may induce erythrocytosis. There is emerging evidence of an AAS withdrawal syndrome, and there is weak, inferential evidence for an association with adverse cardiovascular effects.”

“the most important gaps relate to the long-term outcomes on health and the safest and most effective treatments of AAS withdrawal syndrome and AAS-induced infertility.”

“men who use AASs <1 year typically recover normal hypothalamic-pituitary-testicular axis function within 1 year after cessation. Men who have infertility due to high-dosage AAS use ≥1 year might benefit from short-term treatment with clomiphene or human chorionic gonadotropin.”

**Also in transgender

MC Phases

“no significant variation in muscle strength or muscle endurance could be detected during different well-determined phases of the menstrual cycle.”

“differences between phases within the menstrual cycle for measures of maximum voluntary contraction (MVC), Isokinetic peak torque (IPT) and explosive strength are regarded as trivial to small.”

“hormonal changes through the menstrual cycle were less important to acute health risks and performance than predicted, exercise did not increase risk for amenorrhea and consequent bone mineral loss, and women tolerated G-forces and could be as safe as men in the cockpit if their equipment was designed for normal size and strength ranges.”

“differences in performance were observed between males and females but not between females in either part of their menstrual phase.”

“investigations to date have not consistently demonstrated significant differences in aerobic capacity, anaerobic capacity, aerobic endurance, or muscle strength in any specific menstrual cycle phase.”

“no conclusive evidence that significant menstrual cycle differences exist” “muscular strength does not appear to fluctuate significantly during an ovulatory menstrual cycle.”

“it is essential for each woman to monitor her own response and document the times at which she trains and performs her best.”

“daily mean hormone concentrations measured during different menstrual cycle phases varied by day, yet were generally stable from one month to the next among young, healthy and recreationally active women.”

Furthermore, this review emphasized that there is a need to investigate resistance training’s role in maintaining “skeletal muscle protein metabolism during pregnancy, menopause and in athletes experiencing relative energy deficiency in sport.”

“muscle stretch reflex (MSR) response varies throughout the menstrual cycle with the lowest response around the time of ovulation.”

Oral Contraceptives

“no significant differences in the BC variables (body weight, body mass index, basal metabolism, fat mass, fat-free mass, and total body water) between the MC phases or between the OC phases.”

“ alterations in anaerobic performance throughout the OC cycle occurred with improved performances corresponding to low estrogen and progesterone concentrations”

“a low-dose OC administration consistently suppressed circulating endogenous sex steroid hormone concentrations in OC users to clinical deficiency levels, and that OC synthetically generated high or low hormone environments similar to the normal menstrual cycle to enable performance changes during the menstrual cycle to be studied, and therefore the only effects seen were from the administration of the OC hormones.”

“OCs may be able to minimize any potential side effects and performance influences by taking the lower dose triphasic pills and the newer progestins.”

“may be advantageous for female athletes who are negatively affected by their menstrual cycle, as they may provide a stable yet controllable hormonal milieu for training and competition.”

**Also in OC

Women advantage

“when comparing the curves in terms of the relative force, the endurance time and pain appearance time were longer in women than in men, particularly at lower contraction levels.”

“women exhibited a longer endurance time than men during the isometric task, but there was no difference in endurance performance during the isotonic exercise.”

“under two different conditions (blood flow restricted (BFR) and non-restricted free flow (FF)), women demonstrated greater endurance, as determined by the number of repetitions completed.”

“men were stronger than women for the elbow flexor muscles but exhibited greater muscle fatigue during sustained isometric maximal voluntary contractions (MVCs).”

Male advantage

“men and women have similar patterns of power output recovery between two consecutive short bouts, and that women have a lower overall performance and greater fatigability during sprints.”

“performed to a predefined level of volitional exhaustion, women had a more pronounced loss and prolonged recovery of neuromuscular function compared to their male counterparts.”

No advantage

“despite marked sex differences in fatigability during a purely intermittent and sustained ISO contraction fatigue task, the sex difference was eliminated during a ISO contraction steady state after an active shortening contraction (rTD).”

“in a population of men and women of similar muscle strength, there are no gender differences in torque output decline after a submaximal isometric plantar flexion contraction.” Specifically, when men and women were matched for initial-sprint work experience similar levels of fatigue and systemic, cerebral, and peripheral adjustments during repeated-sprint exercise RSE performed in NM and HY.”

“gender difference in the fatigability of the forearm muscles during intermittent submaximal handgrip contractions, independent of muscle strength.”

“sex differences in muscle fatigue of repeated dynamic contractions is specific to the task requirements, including the velocity of shortening and the muscle group involved.”

Youth

“there were no sex differences for most of the physical test results in children until the age of 13, yet males showed greater endurance (p = 0.020) and upper-body strength than females.”

boys typically scored higher than girls on cardiovascular endurance, muscular strength, muscular endurance, speed and power tests, but lower on the flexibility test.”

“age, weight, standing height and fat-free mass were the predictors of jumping performance among children”, and that “boys and girls had statistically differences for all anthropometric variables.” In fact, this article demonstrated that “within sexes showed a significant difference from 8 years onward with the highest values at 13 years.”

Hormones

“gender affirming hormone therapy (GAHT) in non-athletic transwomen resulted in reductions of lean body mass (LBM), muscle cross sectional area (CSA), muscular strength, and hemoglobin/ hematocrit level, which are all strongly associated with athletic performance.”

clinical and experimental studies show that androgen deprivation reverses, at least in part, previous anabolic effects of T on muscle, bone and hemoglobin, but the pubertal effects of T producing a greater length, diameter and thickness of bones in men, is not reversed upon androgen ablation.”

“T administration dose dependently increases muscle mass and maximal voluntary strength but not fatigability or specific tension.”

Team and staff

“athletic trainers continued to describe a lack of knowledge in caring for transgender student-athletes despite efforts to engage in professional development in order to help them create safe environments.”

“athletic trainers were found to be concerned for their transgender student-athletes, recognizing the potential damage an unsafe environment can cause for their self-image and mental health and wellness.”