Sex hormone profiles of premenarcheal athletes

Role of intensive training in the growth and maturation of artistic gymnasts

Short stature and later maturation of youth artistic gymnasts are often attributed to the effects of intensive training from a young age. Given limitations of available data, inadequate specification of training, failure to consider other factors affecting growth and maturation, and failure to address epidemiological criteria for causality, it has not been possible thus far to establish cause–effect relationships between training and the growth and maturation of young artistic gymnasts. In response to this ongoing debate, the Scientific Commission of the International Gymnastics Federation (FIG) convened a committee to review the current literature and address four questions: (1) Is there a negative effect of training on attained adult stature? (2) Is there a negative effect of training on growth of body segments? (3) Does training attenuate pubertal growth and maturation, specifically, the rate of growth and/or the timing and tempo of maturation? (4) Does training negatively influence the endocrine system, specifically hormones related to growth and pubertal maturation? The basic information for the review was derived from the active involvement of committee members in research on normal variation and clinical aspects of growth and maturation, and on the growth and maturation of artistic gymnasts and other youth athletes. The committee was thus thoroughly familiar with the literature on growth and maturation in general and of gymnasts and young athletes. Relevant data were more available for females than males. Youth who persisted in the sport were a highly select sample, who tended to be shorter for chronological age but who had appropriate weight-for-height. Data for secondary sex characteristics, skeletal age and age at peak height velocity indicated later maturation, but the maturity status of gymnasts overlapped the normal range of variability observed in the general population. Gymnasts as a group demonstrated a pattern of growth and maturation similar to that observed among short-, normal-, late-maturing individuals who were not athletes. Evidence for endocrine changes in gymnasts was inadequate for inferences relative to potential training effects. Allowing for noted limitations, the following conclusions were deemed acceptable: (1) Adult height or near adult height of female and male artistic gymnasts is not compromised by intensive gymnastics training. (2) Gymnastics training does not appear to attenuate growth of upper (sitting height) or lower (legs) body segment lengths. (3) Gymnastics training does not appear to attenuate pubertal growth and maturation, neither rate of growth nor the timing and tempo of the growth spurt. (4) Available data are inadequate to address the issue of intensive gymnastics training and alterations within the endocrine system.

Voice pitch alters mate-choice-relevant perception in hunter-gatherers

In humans, voice pitch is thought to be a cue of underlying quality and an important criterion for mate choice, but data from non-Western cultures have not been provided. Here we test attributions to and preferences for voices with raised and lowered pitch in hunter-gatherers. Using a forced-choice playback experiment, we found that both men and women viewed lower pitched voices in the opposite sex as being better at acquiring resources (e.g. hunting and gathering). While men preferred higher pitched women's voices as marriage partners, women showed no overall preference for voice pitch in men. However, women who were currently breastfeeding had stronger preferences for higher pitched male voices whereas women not currently breastfeeding preferred lower pitched voices. As testosterone is considered a costly signal associated with dominance, heritable immunity to infection and low paternal investment, women's preferences potentially reflect a trade-off between securing good genes and paternal investment. Men's preferences for higher pitched female voices are probably due to an evolved preference for markers of fecundity, reflected in voice pitch.

Hyperandrogenicity is an alternative mechanism underlying oligomenorrhea or amenorrhea in female athletes and may improve physical performance

OBJECTIVE

To evaluate endocrine mechanisms underlying oligomenorrhea or amenorrhea in female athletes.

DESIGN

Cross-sectional study.

SETTING

Women's health clinical research unit at a university hospital.

PATIENT(S)

Age- and BMI-matched groups of athletes active in endurance sports with and without menstrual disturbances and regularly cycling sedentary controls.

INTERVENTION(S)

Groups were compared with respect to endocrine status, body composition, and physical performance.

MAIN OUTCOME MEASURE(S)

Identification of a subgroup of oligomenorrheic or amenorrheic athletes with increased androgen levels and anabolic body composition.

RESULT(S)

A subgroup of 8 of 25 athletes with menstrual disturbances had significantly higher serum levels of free and total testosterone, androstenedione, LH-FSH ratio, and lower SHBG levels than did all other groups. Other oligomenorrheic or amenorrheic athletes had normal values comparable to those in regularly menstruating athletes and controls. The hyperandrogenic subgroup showed a more anabolic body composition, with higher total bone mineral density and upper-lower fat mass ratio than did oligomenorrheic or amenorrheic athletes with normal androgen levels. The hyperandrogenic subgroup had the highest VO2 max and the highest performance values in general.

CONCLUSION(S)

Menstrual disturbances in female athletes are often explained as a consequence of hypothalamic inhibition and caloric deficiency. We suggest that essential hyperandrogenism is an alternative mechanism underlying oligomenorrhea or amenorrhea in some female athletes and may imply an advantage for physical performance.

Does gymnastics training inhibit growth of females?

OBJECTIVE

The increasingly dominant performance of smaller-sized female gymnasts and increased magnitude of training beginning at an early age have prompted public and medical concerns, especially from an auxological perspective. The objective of this review is to determine if gymnastics training inhibits growth of females.

DATA SOURCES

An extensive research of MedLine (PubMed interface) along with cross-referencing was conducted using the Text and MeSH words "gymnastics" in combination with "growth," "maturation," "body height," "body weight," and "growth plate." Our analysis is limited to English articles only.

STUDY SELECTION

All published studies that included data related to the research questions were included.

MAIN RESULTS

Although data from three historical cohort studies indicate that female gymnasts are short even before they begin training, clinical reports and cohort studies do suggest that some female gymnasts experience attenuated growth during training followed by catch-up growth during periods of reduced training or retirement. There is conflicting evidence whether the "catch-up" is complete. There were no studies reporting prevalence or incidence of inadequate growth. Three cohort studies provide evidence of reduced growth but training was not partitioned from other confounding factors in the gymnastics environment. Although there is a paucity of studies examining the link of dietary practices with diminished growth in female gymnasts, a review of related dietary literature indicates the potential for insufficient energy and nutrient intake among female gymnasts.

CONCLUSIONS

Elite level or heavily involved female gymnasts may experience attenuated growth during their years of training and competition followed by catch-up growth during reduced training schedules or the months following retirement. However, a cause-effect relation between gymnastics training and inadequate growth of females has not been demonstrated.

Sex steroid metabolism and menstrual irregularities in the exercising female. A review

This article aims to clarify why, and by which mechanisms, exercise may influence the normal menstrual cycle. Therefore, the vast amount of literature on this subject is reviewed and a critical appraisal of the most widespread hypotheses if offered. The strikingly low body mass which frequently accompanies exercise-related menstrual irregularities (ERMI) has led some authors to develop a hypothesis which postulates that a critical percentage of body fat is essential to trigger normal menstruation. The relevance of any reference to anorexia nervosa to support this view lacks consistency: female athletes differ in many ways from patients with anorexia nervosa, not least in their excellent physical status which is essential to deliver first-class performances. ERMI is not identical to the so-called female athlete triad, a complicated pathology that involves ERMI, premature osteoporosis and disordered eating. ERMI itself does not seem to have any substantial pathological effects as long as attention is paid to preventing osteoporosis or stress fractures which may result from prolonged hypo-estrogenaemia. In the female athlete with ERMI who wishes to conceive, the accompanying subfertility may necessitate a response other than a prompt reduction in training intensity, as this is hardly a first choice for any top athlete. During recent years, a number of prospective studies have greatly contributed to our understanding of the complexity of the mechanisms involved in ERMI. Older hypotheses, such as those considering hyperprolactinaemia as the cornerstone of ERMI, have now been firmly rejected. The present hypotheses emphasise the importance of caloric deficiency and limited energy availability, although they still fail to identify the actual mechanism that causes ERMI. There is, however, evidence that ERMI is produced by a disturbance of the hypothalamic gonadotrophin-releasing hormone oscillator. This disturbance is caused by either an insufficient estrogen or progesterone feedback or by an imbalance of local opioid peptide and catecholamine activities mediated by gamma-aminobutyric acid (GABA), corticotrophin-releasing hormone and insulin-like growth factor-1. More recent experiments have also linked ERMI with changes in steroid metabolism, in particular, an increasing activity of catecholestrogens possibly leading to enhanced intracerebral noradrenaline (norepinephrine) levels that may interfere with normal gonadotrophin release. This article demonstrates that the outcome of the many studies of ERMI is characterised by much controversy and numerous methodological flaws. The importance and complexity of some recent findings necessitate a comprehensive study which links older and newer findings within a critical perspective.

The female athlete

Since the passage of Title IX in 1972, women's participation in physical activity and sports has increased significantly. A concurrent expansion in the body of knowledge regarding women and sports has occurred. Questions regarding menstrual dysfunction and exercise continue, while new questions about menstrual dysfunction and its effect on bone mineral density have arisen. Physical and physiological differences between men and women not only guide treatment, but help fuel policy decisions regarding competition between males and females. It is essential for the physical therapist to remain current on issues related to women and sports in order to better advise and treat the female athlete.

Neuromuscular, metabolic and hormonal profiles of young tennis players and untrained boys

This study compared the neuromuscular, metabolic and hormonal profiles of trained prepubescent tennis players and an untrained group. The boys in the experimental group (n = 9; mean age +/- S.D. = 11.4 +/- 0.5 years) had participated in tennis training for 2.3 +/- 1.0 years and the boys in the control group (n = 9; mean age +/- S.D. = 10.9 +/- 0.4 years) were normal active volunteers. The tennis players were found to be physically more active than the controls when the comparison was made for either 1 year (4.9 +/- 1.8 vs 2.6 +/- 2.5 times per week; P less than 0.05) or for 1 week (3.4 +/- 1.2 vs 0.4 +/- 0.5 times; P less than 0.001) preceding the tests. Choice reaction time was significantly (P less than 0.01) shorter in the experimental group (258 +/- 16 ms) than in the control group (344 +/- 81 ms). Dropping height in the best drop jump was significantly (P less than 0.05) higher in the tennis players (0.46 +/- 0.19 m) than in the control boys (0.27 +/- 0.10 m). The tennis players had significantly lower oxygen consumption at the 'anaerobic threshold' than the controls (P less than 0.05). There were no significant differences between the groups in serum hormone levels. The small differences that existed may have been caused by active participation in sport by the tennis players.

Applied physiology of swimming

Scientific research in swimming over the past 10 to 15 years has been oriented toward multiple aspects that relate to applied and basic physiology, metabolism, biochemistry, and endocrinology. This review considers recent findings on: 1) specific physical characteristics of swimmers; 2) the energetics of swimming; 3) the evaluation of aerobic fitness in swimming; and 4) some metabolic and hormonal aspects related to swimmers. Firstly, the age of finalists in Olympic swimming is not much different from that of the participants from other sports. They are taller and heavier than a reference population of the same age. The height bias in swimming may be the reason for lack of success from some Asian and African countries. Experimental data point toward greater leanness, particularly in female swimmers, than was seen 10 years ago. Overall, female swimmers present a range of 14 to 19% body fat whereas males are much lower (5 to 10%). Secondly, the relationship between O2 uptake and crawl swimming velocity (at training and competitive speeds) is thought to be linear. The energy cost varies between strokes with a dichotomy between the 2 symmetrical and the 2 asymmetrical strokes. Energy expenditure in swimming is represented by the sum of the cost of translational motion (drag) and maintenance of horizontal motion (gravity). The cost of the latter decreases as speed increases. Examination of the question of size-associated effects on the cost of swimming using Huxley's allometric equation (Y = axb) shows an almost direct relationship with passive drag. Expressing energy cost in litres of O2/m/kg is proposed as a better index of technical swimming ability than the traditional expression of VO2/distance in L/km. Thirdly, maximal direct conventional techniques used to evaluate maximal oxygen consumption (VO2 max) in swimming include free swimming, tethered swimming, and flume swimming. Despite the individual peculiarities of each method, with similar experimental conditions similar results for VO2 max will be found. Free swimming (unimpeded) using the backward extrapolation method will, however, lead to reliable and valid results obtained in a condition that is closer to the competitive situation than with a direct test. A maximal indirect field-test has been recently made available. This test can predict VO2 max with an acceptable accuracy (r = 0.877), and provides a mean to evaluate the functional maximal aerobic power in swimming which corresponds to the maximal aerobic swimming velocity.(ABSTRACT TRUNCATED AT 400 WORDS)

Plasma renin and aldosterone changes during twenty minutes' moderate exercise. Influence of posture

The influence of posture on plasma renin and aldosterone changes during exercise performed at a constant relative work load (40%-50% maximal oxygen uptake) was studied in eight healthy men. Each subject carried out two 20-min exercises on an ergocycle at an interval of 8 days; the first exercise was performed in the normal sitting position (upright exercise), the second in a comfortable supine position (supine exercise). In both cases, heart rate and blood pressure were measured as well as plasma renin activity (PRA), aldosterone (ALDO) and osmolality, before and immediately after exercise, and 15 min following the end of exercise. An increase in heart rate, blood pressure, PRA, ALDO and osmolality was noted at the end of each exercise. This increase was greater in the supine exercise than when upright for PRA and ALDO; plasma osmolality and blood pressure showed identical increases for both types of exercise; increase in heart rate was greater when supine than when upright. PRA and ALDO were still elevated 15 min after the upright activity, but had regained their base values in that time after the supine exercise. Our results show that moderate, relatively brief periods of exercise stimulate the production of renin and aldosterone, but the response is less when supine than in the normal upright position.