Effects of oral contraceptives on peak exercise capacity

Abstract

.-We examined the effects of menstrual cycle phase and oral contraceptive (OC) use on peak oxygen consumption (V O2 peak). Six moderately active, eumenorrheic women (25.5 Ϯ 1.5 yr) were studied before and after 4 mo of OC. Subjects were tested during the follicular and luteal phases before OC and the inactive and high-dose phases after OC. Before OC, there were no significant differences between the follicular and luteal phases in any of the variables studied. There were also no differences between the inactive and high-dose phases. Dietary composition, exercise patterns, and peak heart rate, minute ventilation, and respiratory exchange ratio did not change with OC use. However, OC use significantly (P Յ 0.05) increased body weight (59.6 Ϯ 2.3 to 61.2 Ϯ 2.6 kg) and fat mass (13.3 Ϯ 1.3 to 14.5 Ϯ 1.3 kg) and decreased V O2 peak (Ϫ11%, 2.53 Ϯ 0.21 to 2.25 Ϯ 0.18 l/min). In conclusion, 1) endogenous ovarian steroids have little effect on V O2 peak, but 2) the exogenous ovarian steroids in OC decrease peak exercise capacity in moderately physically active young women. menstrual cycle; sex hormones; oxygen consumption; physical fitness and exertion PARTICIPATION BY WOMEN IN both recreational and competitive sports has increased dramatically over the last two decades. In addition, the US Surgeon General's Report on Physical Activity and Health recommends that women of all ages, not just athletes, include a minimum of 30 min of moderate-intensity exercise on most days of the week (25). However, dietary energy insufficiency associated with high-intensity exercise training and competition can increase a woman's risk of experiencing an abnormal menstrual cycle (3, 13). Abnormal menstrual cycles, with chronically low ovarian hormones, may increase the risk for osteopenia, osteoporosis, and fractures (7). Oral contraceptives (OCs) are used for birth control in normally menstruating young women, and, although controversial, OCs have been used to prevent bone loss in amenorrheic athletes (8,16). However, there is concern among athletes that these exogenous ovarian hormones affect exercise performance.Peak oxygen consumption (V O 2 peak ) is considered the "standard" for assessing aerobic exercise capacity (23), and V O 2 peak in women could vary owing to ovarian hormone influences on stroke volume, pulmonary minute ventilation, oxygen-carrying capacity, blood flow, and muscle oxygen utilization. Although the cyclic endogenous ovarian hormone fluctuations across the normal menstrual cycle do not appear to affect V O 2 peak (1, 6, 12), low-dose administration of exogenous estrogen and progesterone may have a greater influence on exercise capacity. Only a few studies have examined the effects of exogenous steroids on exercise performance by use of longitudinal study designs. Although short-term OC use (21 days) did not affect V O 2 peak (2), 6 mo of monophasic OC use was associated with a significant decrease in V O 2 peak in endurancetrained women (18).To our knowledge, no longitudinal studies have examined peak exercise capaci...

Applied Physiology of Female Soccer: An Update

“…Aerobic performance as measured by VO2max has been shown to reduce by 5 -15% in trained and active women using a triphasic OCP [95,96], however, research remains equivocal when considering the monophasic pill [72]. Anaerobic performance, high-intensity intermittent performance and strength appear to be largely unaffected by OCP, however, more well-controlled studies are required [72,93].…”

“…Some studies have indicated that physiological fluctuations that occur throughout the menstrual cycle and/or as a result of OCP usage may affect physical performance [84,93,95]. One study has revealed that the use of the OCP (during the withdrawal phase) has been shown to elicit significantly lower reactive strength index scores during a drop jump.…”

Oral Contraceptive Use May Attenuate Menstrual Cycle-Induced Ventilatory Changes in Endurance Trained Runners

“…Interestingly, the investigators found no changes in endurance performance, heart rate, or ventilation to account for this effect. Casazza et al, reported similar findings in a small study in six "moderately active" women [19]. Participants were studied before and after four months of a triphasic oral contraceptive during the follicular and luteal phases.…”

“…Exogenous progesterone administration has also been associated with increased core body temperature [8]. Data also suggest that during the luteal phase (days [16][17][18][19][20][21][22][23], when estradiol and progesterone levels are elevated, lactate production is decreased in response to exercise [9]. Exogenous administration of progesterone has been linked to increases in ventilation and administration of combined oral contraceptives can decrease fasting blood glucose levels and increase serum triglycerides [10][11][12].…”

2013 Research Consortium Student Awards

“…Most researche xamining the effects of menstrual cycle phase on exercise performance hasu sed inactive or moderately active women (Casazza et al, 2002;Oosthuyse &B osch, 2010;Smekel et al, 2007), and little has been done with highly trained athletes. Becausei ti sm ore important for highly trainedathletes to perform well in their sport than it is for recreational exercisers, it is crucial to understand howt he body responds to the fluctuations of hormones in the menstrual cycle in eliteathletes and howit can affect physiological responses to exercise.…”