Response of women using oral contraception to exercise in the heat
MetadataShow full item record
Purpose: To compare the response of long-term oral contraceptive users (WomenOC; n = 8) to naturally menstruating women (WomenNM; n = 8) at rest and during exercise in temperate (TEMP; 22 °C) and hot (HEAT; 35 °C) conditions. Methods: Participants performed a three-stage cycling trial in each condition at 90, 135, and 180% of lactate threshold 1 (total = 52.5 min). Heart rate (HR) and core temperature (Tc) were recorded continuously, whereas blood pressure (BP), ratings of perceived exertion (RPE), blood lactate [La−], and skin blood flow (BFsk) were recorded every 7.5 min. Results: Baseline Tc was higher in WomenOC (37.5 ± 0.2, 37.6 ± 0.3 °C) than WomenNM (37.2 ± 0.2, 37.0 ± 0.4 °C) before the TEMP (p = 0.03) and HEAT (p < 0.01) trials, respectively. This difference remained for 22.5 min into both trials (p ≤ 0.05), after which time no between-group differences were found (p > 0.05). BFsk measured in WomenNM plateaued from 7.5 min in the HEAT, whereas BFsk measured in WomenOC increased for 15.0 min (p = 0.02) before plateauing. There were no between-group differences in HR, BP, or blood [La−] before or throughout either trial (p > 0.05). WomenOC had higher (p ≤ 0.04) RPE values than WomenNM in the HEAT, reporting 8 ± 1 and 6 ± 2 at the end of Stage 3, respectively. Conclusions: WomenOC concluded both trials with a comparable Tc to WomenNM, but had a prolonged BFsk response and elevated RPE in the HEAT. Changes to BFsk and RPE observed in women using OC may have implications for exercise tolerance in hot conditions.
European Journal of Applied Physiology
Human Movement and Sports Science not elsewhere classified