Effect of oral contraceptives and hormone replacement therapy on bone mineral density in premenopausal and perimenopausal women: a systematic review.

Seventy five articles on the effect of oral contraceptives and other hormone replacement on bone density in premenopausal and perimenopausal women were reviewed. The evidence was appraised using the Oxford Centre for Evidence-Based Medicine levels of evidence. There is good evidence for a positive effect of oral contraceptives on bone density in perimenopausal women, and fair evidence for a positive effect in "hypothalamic" oligo/amenorrhoeic premenopausal women. There is limited evidence for a positive effect in healthy and anorexic premenopausal women. In hypothalamic oligo/amenorrhoeic women, baseline bone density has been shown to be significantly lower than that in healthy controls, therefore the decision to treat is clinically more important. The ideal formulation(s) and duration of treatment remain to be determined by further longitudinal and prospective randomised controlled trials in larger subject populations.

Decreased maximal aerobic capacity with use of a triphasic oral contraceptive in highly active women: a randomised controlled trial.

BACKGROUND: Oral contraceptives are commonly used by women athletes. However, their effect on athletic performance is unclear. OBJECTIVES: To examine the effects of a moderate dose, triphasic oral contraceptive on measures of athletic performance in highly trained women athletes. METHODS: This is a double blind, placebo controlled trial in 14 women with ovulatory menstrual cycles and maximal aerobic capacity (VO(2)MAX) >/==" BORDER="0">50 ml/kg/min. Four measures of athletic performance were tested: VO(2)MAX, anaerobic capacity (anaerobic speed test), aerobic endurance (time to fatigue at 90% of VO(2)MAX), and isokinetic strength (Cybex II dynamometer). Height, weight, and six skinfold measurements were also recorded. All these observational tests were completed during both the follicular and mid-luteal phases of an ovulatory menstrual cycle. Cycle phases were confirmed by assaying plasma oestradiol and progesterone. Participants were subsequently randomly assigned to either a tricyclic oral contraceptive or placebo and retested in identical fashion (oral contraceptive phase). RESULTS: Absolute and relative changes in VO(2)MAX from follicular to oral contraceptive phase decreased in the oral contraceptive group by 4.7%, whereas the placebo group showed a slight increase (+1.5%) over the same time period. Two of the women taking oral contraceptive had decreases of 4 and 9 ml/kg/min. In contrast, most women in the placebo group improved or maintained VO(2)MAX. There was also a significant increase in the sum of skinfolds in women taking oral contraceptive compared with those taking placebo (p<0.01). There were no significant changes in other physiological variables (maximum ventilation, heart rate, respiratory exchange ratio, packed cell volume) or measures of performance (anaerobic speed test, aerobic endurance, isokinetic strength) as a function of oral contraceptive treatment. CONCLUSIONS: The decrease in VO(2)MAX that occurs when oral contraceptive is taken may influence elite sporting performance in some women. Further studies are required to determine the mechanisms of this change.

Relationship between athletic performance and menstrual cycle.

The female sex steroid hormones have multiple actions on body systems other than the reproductive axis. Female athletes, coaches, medical professionals, and researchers have long been concerned about the potential impact of menstrual cycle fluctuations in these hormones on components of athletic performance. Estrogen is known to affect the cardiovascular system, bone, and the brain; progesterone primarily influences thermoregulation and ventilation. Substrate metabolism is likely altered by both hormones. Net physiological effects can be either opposing or synergistic and are determined by the relative proportions of each. Nevertheless, 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. The course of some chronic diseases may vary slightly during the menstrual cycle, but the mechanism is currently unknown. Recent research in underlying hormonal causes for anterior cruciate ligament (ACL) injuries also is not convincing.

Menstrual cycle, contraception, and performance.

Although understanding of the unique physiology of the female athlete has increased, there are still many questions to be answered. Endogenous and exogenous female sex steroids have been shown to influence various cardiovascular, respiratory, and metabolic parameters, but these changes probably have minimal impact on the ability of most recreational athletes to participate in and enjoy their sport. Statistically significant data may or may not have clinical or performance relevance. By the same token, a statistically nonsignificant change may mean the difference between first and second place to an elite athlete. For an athlete concerned about maximizing performance, individual variability in menstrual cycle changes to various performance parameters must be considered. It is difficult to predict how accurately controlled laboratory findings from a study population apply to an individual competitor on the playing field. Athletes taking OCs for contraception or for menstrual cycle control may be able to minimize any potential side effects and performance influences by taking the lower dose triphasic pills and the newer progestins. For women with menstrual dysfunction, OCs may provide a predictable hormonal milieu for training and competition. Further scientific study is needed using large-scale, prospective, randomized clinical trials on trained athletes and accurate hormonal measurements to determine the phase of the menstrual cycle to determine short- and long-term effects of cycle phase and OCs in exercising women. As more questions continue to be answered, physicians and sport scientists will be better able to guide women not only to maximize their performance but to ensure lifelong good health.

Effects of menstrual cycle phase on athletic performance.

The purpose of this study was to examine the effects of menstrual cycle phase on four selected indices of athletic performance: aerobic capacity, anaerobic capacity, isokinetic strength, and high intensity endurance. Sixteen eumenorrheic women (VO2max > or = 50 ml.kg-1.min-1) were tested during the early follicular (F) and midluteal (L) phases of the menstrual cycle. Cycle phases were confirmed by serum estradiol and progesterone assays. No significant differences were observed between F and L tests in weight, percent body fat, sum of skinfolds, hemoglobin concentration, hematocrit, maximum heart rate, maximum minute ventilation, maximum respiratory exchange ratio, anaerobic performance, endurance time to fatigue (at 90% of VO2max), or isokinetic strength of knee flexion and extension. Both absolute and relative VO2max, however, were slightly lower in L than in F (F = 3.19 +/- 0.09.min-1, L = 3.13 +/- 0.08.min-1, P = 0.04; and F = 53.7 +/- 0.9 ml.kg-1.min-1, L = 52.8 +/- 0.8 ml.kg-1.min-1, P = 0.06). These results suggest that the cyclic increases in endogenous female steroid hormones of an ovulatory menstrual cycle may have a slight, deleterious influence on aerobic capacity, with potential implications for individual athletes. Nevertheless, the cycle phase did not impact significantly on the majority of the other performance tests and cardiorespiratory variables measured in this study.

The effect of the phase of the menstrual cycle and the birth control pill on athletic performance.

Investigators are not in agreement on the effects of either the phase of the menstrual cycle, or the administration of OCAs on athletic performance. It appears, however, that apart from subtle changes in some variables, for most women there is no significant effect. Medals have been won and world records set in any phase of the menstrual cycle, and also by women taking OCAs. In terms of documentation of cycle phase, newer hormonal measurement techniques such as the levels of urinary luteinizing hormone (LH) to detect ovulation or salivary progesterone, should make it easier in the future to obviate the methodologic difficulties encountered in earlier studies. Further studies should also focus on the midcycle estradiol surge as well, in order to determine the relative contributions of estrogen and progesterone to any observed performance changes. Given the possibility that some cardiovascular, respiratory, and metabolic variables may change slightly during the course of a regular ovulatory menstrual cycle, it behooves researchers who are using women as subjects in other types of studies to standardize the menstrual cycle phase in which they are tested, in order to eliminate any possible confounding effects due to hormonal variation. Regarding the effects of oral contraceptives on performance, any conclusions from the studies to date are complicated by the proliferation of preparations currently on the market. Further studies are needed on monophasic, biphasic and triphasic formulations, including OCAs with the newer progestins (desogestrel, gestodene and norgestimate), as well as the progesterone-only agents (both oral and injectable). Prospective double blind randomized studies must be done, using a proper control group. The difficulty with this technique, however, is that women in the control group will inevitably be in various phases of the cycle, so accurate hormonal documentation is also essential in order to correctly interpret the findings. Just as the past few decades have seen a significant advancement in the participation of women in sports, future years should bring an enhanced scientific knowledge base about the interactions of the special hormonal considerations of the exercising woman throughout her reproductive life cycle.

PIP: Research has not yet conclusively settled the question of potential effects of oral contraceptives (OCs) or of the phase of the menstrual cycle on athletic performance. The current evidence suggests that most women's athletic performance is not affected by OCs or the phase of the menstrual cycle. In fact, female athletes have won competitions and set world records at all phases of the menstrual cycle. Even though many female athletes use OCs, the sports medicine community knows little about the possible OC-induced metabolic effects on athletic performance. Sports medicine researchers can use newer hormonal measurement techniques (e.g., urinary luteinizing hormone levels) to detect ovulation or salivary progesterone, which avoid the methodological difficulties in earlier studies. They should also concentrate on the midcycle estradiol surge to learn the relative contributions of estrogen and progesterone to changes in athletic performance. Since some cardiovascular, respiratory, and metabolic variables may change during a regular menstrual cycle, researchers should also standardize the menstrual cycle phase in which female athletes are tested to control for any possible confounding effects caused by hormonal variation. The increase in the variety of OC preparations available to women complicate any conclusions about the effects of OCs on athletic performance from existing studies. Researchers need to conduct performance studies in women using the monophasic, biphasic, and triphasic OC formulations, including those with the newer progestins (desogestrel, gestodene, and norgestimate), and the oral and injectable progestin-only contraceptive agents. They also need to conduct prospective double blind randomized trials using a proper control group. These studies should include accurate hormonal documentation to correctly interpret the findings. This article reviews athletic performance; the menstrual cycle; estrogen and progesterone effects; menstrual irregularities; metabolic, respiratory, cardiovascular, hemodynamic responses; and strength.

Effect of the different phases of the menstrual cycle and oral contraceptives on athletic performance.

The female athlete, during her reproductive years, has a complex and ever-changing milieu of female steroid hormones, whether it is the endogenous variations in estradiol and progesterone of a regular menstrual cycle, or the exogenous synthetic hormones of the oral contraceptives. Both estrogens and progestins have individual, interactive and sometimes opposing physiological actions with potential implications for the exercising female. In retrospective surveys on the menstrual cycle and performance, from 37 to 63% of athletes did not report any cycle 'phase' detriment, while 13 to 29% reported an improvement during menstruation. The best performances were generally in the immediate postmenstrual days, with the worse performances during the premenstrual interval and the first few days of menstrual flow. However, this type of study has an inherent built-in bias, and is further limited by the lack of substantiation of cycle phase. Many of the women studied associated premenstrual symptoms, such as fluid retention, weight gain, mood changes, and dysmenorrhoea with performance decrement. Such factors have also been causally linked with an increase in traumatic musculoskeletal injuries during the premenstrual and menstrual period. Neuromuscular coordination, manual dexterity, judgement and reaction time for complex tests have been shown to be adversely affected in women with premenstrual syndrome or symptoms, but confounding variables may include nutrition status and blood sugar levels. In addition, not all women suffer to the same level with premenstrual symptoms. Fluctuations in many physiological functions occur throughout the normal menstrual cycle. Results of early studies are difficult to interpret owing to the small numbers of women studied, wide range of fitness levels, and variability in the definitions of cycle phase. Nevertheless, investigators did not document any significant changes in measures of athletic performance as a function of timing of testing during the menstrual cycle. Swimmers have shown a premenstrual worsening of performance times, with improvement during the menstrual phase and on the eighth day of the cycle. An increase in perceived exertion was noted premenstrually and during the early menstrual stage with very intense exercise. In cross-country skiers, the best times were recorded in the postovulatory and postmenstrual phases, prompting the recommendation that training loads be selected according to cycle phase to achieve maximum benefit. Investigations using estradiol and progesterone levels as a confirmatory index of ovulation have not generally found significant differences across the cycle in either maximal or submaximal exercise responses, although a slight decrease in aerobic capacity during the luteal phase has been reported.(ABSTRACT TRUNCATED AT 400 WORDS)

Organizing Sports Medicine Coverage at the Canada Summer Games.

In brief: This article documents the experience with medical coverage for the 1985 Canada Summer Games to help determine the demands of caring for athletes at this level of competition. A total of 599 medical and physiotherapy treatments were given to the 339 members of the British Columbian team (including 20 mission staff) during the two weeks of the games. Most treatments were carried out in the clinic by physiotherapists, suggesting that athletes were seen more frequently for chronic musculoskeletal complaints than for acute medical emergencies. However, physicians responsible for on-site care must be equipped to treat conditions ranging from corneal abrasions to acute head or neck injuries.