Aerobic Exercise Performance is Reduced in the Mid‐luteal Compared to the Mid‐follicular Phase of the Menstrual Cycle in Eumenorrheic Women

Abstract

PurposeUp to 40% of women believe their menstrual cycle affects their aerobic exercise performance. Fluctuations in sex hormone concentrations heighten many physiological and psychological responses to aerobic exercise in the mid‐luteal (ML) compared to the mid‐follicular (MF) phase of the menstrual cycle, which can promote reductions in aerobic exercise performance in the ML phase. However, the literature is equivocal regarding whether aerobic exercise performance differs between the ML and MF phases. Therefore, we tested the hypothesis that aerobic exercise performance is impaired in the ML compared to the MF phase of the menstrual cycle.MethodsTwelve recreationally active eumenorrheic women (25 ± 6 y) completed three familiarization and two experimental exercise sessions across the span of 3 consecutive menstrual cycles during the MF and ML phases. Saliva samples were collected at the beginning of each test session for analysis of progesterone and estrogen concentration. Each exercise session consisted an 8 km time trial that was preceded by 5 min of constant load exercise at a power output both 10% below (88 ± 19 W) and 10% above (108 ± 19 W) the gas exchange threshold (GET). Total mood disturbance was calculated from the Profile of Mood States administered prior to exercise. Heart rate, ventilation, and oxygen uptake were continuously recorded throughout exercise. Ratings of perceived exertion (RPE) and ratings of fatigue were assessed during the time trial using visual analogue scales.ResultsProgesterone concentration was 250± 386 pg/ml higher in the ML phase compared to the MF phase (P = 0.04), while estrogen concentration did not differ between phases (4.1 ± 1.6 vs. 5.7 ± 1.6 pg/ml, P = 0.32). Total mood disturbance was greater during the ML compared with the MF phase (123 ± 19 vs. 112 ± 22 a.u., P = 0.03) indicating a more negative mood state during the ML phase. During constant load exercise 10% below GET, ventilation (38.2 ± 5.0 vs. 35.4 ± 4.7 L/min, P = 0.03) and oxygen uptake (1.4 ± 0.2 vs. 1.3 ± 0.2 L/min, P = 0.03) were higher during the ML phase, but heart rate did not differ between phases (P = 0.67). Ventilation (P =0.11), oxygen uptake (P = 0.23), and heart rate (P =0.50) did not differ between phases during exercise at 10% above GET. Mean power output was lower during the ML phase (115 ± 28 vs. 125 ± 27 W, P<0.01) which led to a slower time trial in the ML phase (18.3 ± 2.0 min) compared to the MF phase (17.8 ± 1.7 min, P=0.03). Ratings of fatigue were greater during the ML phase from 4–8 km (P ≤0.05), while RPE did not differ between phases (P = 0.09). Heart rate (P = 0.85), ventilation (P = 0.53), and oxygen uptake (P = 0.32) did not differ between phases during the time trial.ConclusionAerobic exercise performance is reduced in the ML phase compared to the MF phase of the menstrual cycle in recreationally active eumenorrheic women. This is likely explained by a negative mood state pre‐exercise in the ML phase along with increased ratings of fatigue that persisted during the self‐paced exercise.