David C. Cumming

Reproductive hormone increases in response to acute exercise in men

The increase in serum testosterone levels generally observed with intense, short-term exercise remains unexplained since most investigators have not reported any increase in the levels of luteinizing hormone, the pituitary glycoprotein most responsible for testicular steroidogenesis. Hemoconcentration and decreased metabolic clearance have been suggested as mechanisms to explain the exercise-associated testosterone increase. Such non-specific mechanisms should apply to other steroid hormones as well as to testosterone. To investigate whether the exercise-induced changes in other steroid hormones were similar to that of testosterone, we measured serum levels of testosterone, androstenedione, dehydroepiandrosterone, and cortisol as well as gonadotropins, luteinizing hormone and follicle-stimulating hormone, and prolactin at 5-15 min intervals throughout progressive maximal intensity exercise on a cycle ergometer. Significant increases were observed with all hormones with exercise. The increase in serum testosterone began prior to exercise, peaked at 20 min after the beginning of exercise, and fell to baseline within 10 min. The serum luteinizing hormone increase was synchronous with that of testosterone, suggesting that gonadotropin stimulation was not responsible for the testosterone increment. The increments in serum cortisol, androstenedione, dehydroepiandrosterone, and prolactin levels were simultaneous but began 25-30 min after that of testosterone in all subjects. These findings, therefore, suggest that, contrary to previous evidence, the exercise-associated increase in serum testosterone results predominantly from a specific mechanism, presumably involving increased testicular production without gonadotropin stimulation.

Work loss associated with increased menstrual loss in the United States.

OBJECTIVE To estimate the effect of increased menstrual flow on the loss of work. METHODS Heavy or otherwise abnormal menstrual bleeding is a common problem among women in the reproductive age range. Until now, there has been no evidence of its effect on absences from work. We used data from the National Health Interview Survey 1999, a personal interview household survey using a nationwide representative sample of the civilian noninstitutionalized population of the United States. Participants were 3133 women aged between 18 and 64 years who reported having a natural menstrual period in the last 12 months and in the last 3 months, never having taken medication containing estrogen (except past use of oral contraceptives), and never having been told that they had reproductive cancer. Analysis was performed using data from 2805 women, 373 having self‐described heavy flow and 2432 having normal flow. The main outcome measure was work loss associated with the degree of menstrual flow. RESULTS Using binary logistic regression, age, marital status, education, family size, perception of health, and flow of menstrual periods are associated with work losses (P < .05). The odds ratio of 0.72 (95% confidence interval 0.56, 0.92) indicates that women who have a heavier flow are 72% as likely to be working as are women who have a lighter or normal flow. CONCLUSION Menstrual bleeding has significant economic implications for women in the workplace: work loss from increased blood flow is estimated to be

The Effects of Exercise on Reproductive Function in Men

1692 annually per woman.

Does anovulation exist in eumenorrheic women

SummaryPhysical activity has a range of effects on male reproductive function depending upon the intensity and duration of the activity and the fitness of the individual. In general, it appears that relatively short, intense exercise increases serum testosterone levels, but there is debate to what degree haemoconcentration, decreased clearance and/or increased synthesis are involved. It is clear from the promptness of the testosterone increment that the mechanism does not involve gonadotrophin stimulation of the testes.There is suppression of serum testosterone levels during and subsequent to more prolonged exercise (and to some extent in the hours following intense short term exercise). Again the mechanisms are not clear: a variety of systems could influence the decrease of testosterone synthesis, including decreased gonadotrophin, increased cortisol, catecholamine or prolactin levels, or perhaps even an accumulation of metabolic waste materials.Endurance training induces changes in the function of the reproductive axis in men in a manner which appears similar to the changes in women. As in women, there is a subclinical inhibition of normal reproductive function but it is unclear whether clinical expression of reproductive suppression is common in men.The long term, physiological suppression of the hypothalamic-pituitary-gonadal axis in men is probably not of major significance but it is clear that further investigation in several areas is essential to provide continuing reassurance that ‘exercise is good for you’.

Psychological well-being and coping patterns in infertile men

Abstract Objective To determine whether anovulation exists in normally menstruating women. Methods In a database of 550 consecutive couples seeking pregnancy, results of the midluteal serum progesterone level analysis planned for 7 days before the onset of the next menses were examined in women with predictable cycles shorter than 35 days. Results Of the 550 couples seeking pregnancy, 410 of the female partners (74.5%) were eumenorrheic. Fifteen of these women (3.7%) had apparently anovulatory cycles with a progesterone lower than the normal ovulatory value of 15 nmol/L. Further examination showed that four of the 15 women (26.7%) had an isolated prolonged cycle, whereas an additional four (26.7%) failed to have their sample taken at an appropriate time. One (6.7%) had a low progesterone level that was normal in the subsequent cycle. Two patients (13.3%) were older than 40, both having elevated early follicular follicle-stimulating hormone levels. One patient (6.7%) conceived in the following menstrual cycle without further evaluation. The three remaining women (20%) showed consistently apparently anovulatory cycles. However, the levels were exclusively above the follicular range. Conclusion Our findings cast doubt on the concept of anovulatory cycles in eumenorrheic women and suggest that further examination of the lower level of ovulatory progesterone may indeed be necessary.

THE EFFECTS OF ACUTE EXERCISE ON PULSATILE LH RELEASE IN HIGH-MILEAGE MALE RUNNERS

OBJECTIVE To determine whether differences existed in mood and coping styles among fertile men, oligoasthenospermic men, or euspermic men whose wives were undergoing ovulation stimulation with clomiphene and IUI. DESIGN A cross-sectional research design. SETTING Hospital-based academic fertility clinic. PATIENT(S) 30 fertile men with currently pregnant wives, 30 euspermic and 30 oligoasthenospermic men in couples undergoing ovulation stimulation with clomiphene and IUI. INTERVENTION(S) Measures of psychological well-being and coping were administered. MAIN OUTCOME MEASURE(S) Biodemographic information, and psychometric measures of mood and coping. RESULT(S) There were no significant differences among the groups on any of the measures except the Family Inventory of Life Events (FILE), in which fertile men reported higher stress levels. FILE scores in all groups were moderate, indicating typical levels of family stress. CONCLUSION(S) Mood and coping in the three groups were similar. This study suggests that mens psychological adjustment to their own infertility and to unexplained infertility is generally healthy.

Physical Activity, Nutrition, and Reproduction

Evidence suggests that acute exercise and endurance training has a suppressive effect on the hypothalamic—pituitary—gonadal (HPG) axis in men and women. To determine if training and acute exercise influence the neuroendocrine regulation of the HPG axis in men we examined pulsatile LH release in six male endurance runners with a training volume of at least 80 km per week, and compared this with values in six age‐matched sedentary controls. Blood samples were obtained through an indwelling i.v. cannula from the subjects at 15‐min intervals for 6 h following 24 h without significant physical activity and again, in the runners, following 60 min of running at a speed equivalent to 5% below the anaerobic threshold. Mean LH pulse frequency and amplitude, as well as areas under the LH pulses and total LH curve, were calculated but only the mean post‐exercise area under the total LH curve area was significantly lower than basal values (P<0.05) following exercise compared with the resting values in runners. Other measures of LH release did not change with acute exercise. Basal and pre‐exercise testosterone levels were also measured and found to be at the lower end of normal men. The mean pre‐exercise serum testosterone levels were significantly higher than basal levels. Mean testosterone levels, mean pulse amplitude, and mean area under the LH curve were significantly lower in resting runners than in the controls. The data suggest that exercise induces a general lowering of LH levels but does not inhibit LH pulsatile release. An anticipatory increase in serum testosterone occurred before exercise.

The late luteal phase in infertile women: comparison of simultaneous endometrial biopsy and progesterone levels

Thin high mileage female and male runners often have reproductive problems. Strenuous physical activity can affect the hypothalamic-pituitary-gonadal (HPG) axis function of both females and males but physical activity alone probably does not cause reproductive problems. Nutritional changes and changes in the metabolic balance are likely responsible for the exercise-associated reproductive problems. Reproductive dysfunction in female athletes include pubertal delay (age at menarche 15.5 years for ballet dancers 15 years for athletes trained before menarche vs. 12.5 years for controls) luteal phase inadequacy anovulatory cycles secondary amenorrhea and oligomenorrhea. Male athletes tend to have reduced circulating testosterone androstenedione and luteinizing hormone levels. Endurance training has comparable chronic effects on the HPG axis in women and men. A possible mechanism of inhibition is changes to the gonadotropin releasing hormone-gonadotropin axis the cause of the changes is unknown. Neurotransmitter precursor deficiencies changes in thyroid function activation of stress hormones changes in glucoregulatory and other metabolic hormones changes in steroid metabolism in fat tissue changes in hepatic metabolism of binding proteins or an exaggerated peripheral response to exercise in a nutritionally stressed person are possible causes of the changes to the axis. Factors in the emergence of exercise-associated menstrual dysfunction include the physical and emotional stress of training and/or competition predisposition to menstrual irregularity inadequate nutrition weight loss and low body fat. Reduced physical activity reverses menstrual dysfunction. Further research is needed to clarify the relative importance of dietary deficiencies energy balance and physical activity in bringing about reproductive change and dysfunction. Obstacles to resolving the complex interrelationships are imprecision of dietary evaluation difficulty of accuracy versus freedom in energy balance measurements and the conceptual barrier of the body fat theory.

The effect of acute exercise on pulsatile release of luteinizing hormone in women runners

Endometrial biopsy specimens were obtained from 107 normally menstruating infertile women 2 to 3 days before the anticipated onset of menses and were day-dated according to histologic criteria. A simultaneous blood sample was obtained for measurement of progesterone (P) and beta-subunit of human chorionic gonadotropin. Of 98 biopsies which could be accurately dated, 56 were in-phase (IP) and 42 were out-of-phase (OOP). Mean serum P levels were significantly lower in women with OOP biopsies undertaken more than 4 days before the onset of menses. A sharp decline in serum P levels was observed in women with IP but not OOP biopsies, so that on the final premenstrual day serum P levels were significantly higher than normal in women with OOP biopsies. Pregnancy continued without interruption in two of six patients who underwent biopsy in the cycle of conception. One patient had an ectopic pregnancy; and the three remaining pregnant patients, all with subnormal P values, aborted. The study suggests that there is a high frequency of minor abnormalities in luteal function in normally menstruating, infertile women for whom tubal and male factors were normal. The frequency of subclinical pregnancy (2 of 107) was lower than anticipated from earlier studies.

Significance of intrauterine adhesions detected hysteroscopically in eumenorrheic infertile women and role of antecedent curettage in their formation

Endurance exercise has been associated with reproductive dysfunction. We have previously suggested that pulsatile release of luteinizing hormone is impaired at rest in normal menstruating runners compared with sedentary women. To determine whether acute exercise had any effect on pulsatile release of luteinizing hormone we investigated serum luteinizing hormone levels in six normal menstruating runners at rest and after 60 minutes of running exercise. Exercise induced an increment in circulating luteinizing hormone levels greater than the change in hematocrit. The luteinizing hormone pulse frequency, calculated as the number of luteinizing hormone pulses per 6 hours, was reduced after exercise compared with values obtained at rest. There was no significant difference in pulse amplitude or area under the 6-hour curve between resting and postexercise situations. These data suggest that acute exercise has an inhibitory effect on luteinizing hormone pulsatile release at the hypothalamic level in eumenorrheic runners that is in addition to the previously described effect of training.