Effect of administration of monophasic oral contraceptive on the body composition and aerobic and anaerobic capacities of female athletes

The oral contraceptive cycle and its influences on maximal and submaximal endurance parameters in elite handball players

The usage of the oral contraceptive pill is widespread among athletes of various levels. However, there is limited knowledge on how the intake of the pill alters the submaximal and maximal endurance parameters between the oral contraceptive phases. Therefore, the aim of this study was to examine potential differences between the pill intake and withdrawal phase on endurance-related parameters in first-division handball players. In total, 15 female team handball players performed two graded exercise tests until volitional exhaustion on a motorized treadmill. Tests were performed during the pill intake (days 16-17) and withdrawal phase (day 2-3). Throughout the test, respiratory gases were measured breath-by-breath, and the heart rate was measured continuously. Before and after the graded exercise test, blood samples were obtained in order to assess the blood lactate concentration. Before each test, venous blood samples were taken to determine endogenous sex hormone levels. Ventilatory parameters (V ˙ O2, V ˙ CO2, and V ˙ E, and respiratory equivalents for V ˙ O2 and V ˙ CO2) were measured, and the oxidation of fat and carbohydrates was calculated. A paired-sample t-test was used to assess differences between the two time points, and the significance was accepted as p < 0.050. Significant differences with lower values during the consumption phase were found for absolute (mean difference ± SD: 88 ± 131 mL∙min-1; p = 0.021) and relative V ˙ O2peak (mean difference ± SD: 1 ± 2 mL∙min-1∙kg-1; p = 0.012). Higher values during the consumption phase were found for submaximal respiratory equivalents for V ˙ O2 (mean difference ± SD: -1.1 ± 1.7; p = 0.028) and V ˙ CO2 (mean difference ± SD: -0.9 ± 1.5; p = 0.032). No differences were found for all other parameters, including differences for endogenous sex hormones (p > 0.050). The results of the current study suggest only marginal and physiologically insignificant differences in endurance-related parameters between oral contraceptive phases.

Influence of menstrual cycle phase and oral contraceptive phase on exercise performance in endurance-trained females

BACKGROUND

Limited data exists on the influence of menstrual cycle (MC) phase and oral contraceptive (OC) phase on physical performance in endurance-trained females due to poor control regarding MC verification and differentiation. We aimed to evaluate exercise performance and the respiratory response to exercise in three distinct phases of the MC and OC cycle in endurance-trained females.

METHODS

Using a prospective cohort study design, we recruited trained females (Vo2max 52±4 mL O2/min/kg) who were either not using oral contraceptives (NOC) or using monophasic OCs. NOC were tested in the early and late follicular phase (FP) and the mid-luteal phase (LP). OC-users were tested in the withdrawal phase (WP) and two times in the active OC phase (OCP). The test battery included DXA scans, blood sampling, a submaximal bike test, a maximal isometric knee-extensor strength test, 4 and 20-second bike sprints, and a 6 min time trial on a bike. MC phases were verified by the use of ovulation kits and circulating sex hormone levels.

RESULTS

After the exclusion of four NOCs due to inadequate sex hormone levels, 11 NOC and 13 OC users were included in the final analysis. 6 min time trial performance, sprint performance, and most submaximal exercise intensity variables did not differ between MC phases and OC cycle phases. However, in NOC, ventilation (L/min) during exercise at 30% of aerobic peak power was 7.6% lower in the late FP compared to the LP (P<0.05). In OC users, muscle strength was 3.9% higher in the early OCP compared to WP (P<0.05), whereas body mass was higher in the late OCP compared to WP (P<0.05).

CONCLUSIONS

Collectively, our study suggests that MC phase and OCP influence exercise performance to a limited extent in endurance-trained females.

The influence of the menstrual cycle and hormonal contraceptives on cardiorespiratory fitness in physically active women: A systematic review and meta-analysis

Objective

To systematically review and summarize the existing evidence related to the influence of the menstrual cycle (MC) and hormonal contraceptive (HC) use on V˙O_2max in physically active women.

Methods

This systematic review and meta-analysis conforms to the PRISMA statement guidelines. Four (sub-)meta-analyses were performed. Two focused on longitudinal studies examining the same women several times to compare the V˙O_2max during the different menstrual phases or oral contraceptive (OC) use and withdrawal. Two meta-analyses examined if there is a difference in V˙O_2max between OC users and normally menstruating women by analyzing cross-sectional studies assigning physically active women to one of these two groups as well as intervention-based studies (cross-over studies, randomized controlled trials considering only the data of the intervention group) comparing women intra-individually with and without OCs.

Results

Nine of the included studies (107 women) evaluated the influence of the MC, five studies (69 women) the impact of OCs on V˙O_2max, and six studies investigated both topics (88 women). A mean difference of V˙O_2max -0.03 ml/kg/min (95%CI -1.06 to 1.01) between the early follicular and luteal menstrual phase was observed. Between the active and inactive phases of OCs, a mean difference of -0.11 ml/kg/min (95%CI -2.32 to 2.10) was found. The inter-individual comparison of naturally menstruating women and OC users showed a mean difference in V˙O_2max of 0.23 ml/kg/min (95% CI -2.33 to 2.79) in favor of OC use. The intra-individual comparison of the same women showed a mean decrease in V˙O_2max of -0.84 ml/kg/min (95% CI -2.38 to 0.70) after a new start with OCs.

Conclusions

Our meta-analyses showed no effects of the MC or the OCs on V˙O_2max. More high-quality studies are needed determining the MC phases more precisely, including OCs with the current standard formulations and comparing the influence of different progestins.

The Specificities of Elite Female Athletes: A Multidisciplinary Approach

Female athletes have garnered considerable attention in the last few years as more and more women participate in sports events. However, despite the well-known repercussions of female sex hormones, few studies have investigated the specificities of elite female athletes. In this review, we present the current but still limited data on how normal menstrual phases, altered menstrual phases, and hormonal contraception affect both physical and cognitive performances in these elite athletes. To examine the implicated mechanisms, as well as the potential performances and health risks in this population, we then take a broader multidisciplinary approach and report on the causal/reciprocal relationships between hormonal status and mental and physical health in young (18-40 years) healthy females, both trained and untrained. We thus cover the research on both physiological and psychological variables, as well as on the Athlete Biological Passport used for anti-doping purposes. We consider the fairly frequent discrepancies and summarize the current knowledge in this new field of interest. Last, we conclude with some practical guidelines for eliciting improvements in physical and cognitive performance while minimizing the health risks for female athletes.