Minahan Clare, Melnikoff Marina, Quinn Karlee, Larsen Brianna
Griffith Sports Physiology, School of Allied Health Sciences, Griffith University, Gold Coast, QLD, Australia.
Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD, Australia.
Eur J Appl Physiol. 2017 Jul;117(7):1383-1391. doi: 10.1007/s00421-017-3628-7. Epub 2017 May 5.
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.
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 (T ) were recorded continuously, whereas blood pressure (BP), ratings of perceived exertion (RPE), blood lactate [La], and skin blood flow (BF) were recorded every 7.5 min.
Baseline T 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). BF measured in WomenNM plateaued from 7.5 min in the HEAT, whereas BF 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.
WomenOC concluded both trials with a comparable T to WomenNM, but had a prolonged BF response and elevated RPE in the HEAT. Changes to BF and RPE observed in women using OC may have implications for exercise tolerance in hot conditions.
比较长期口服避孕药使用者（女性口服避孕药组；n = 8）与自然月经周期女性（自然月经女性组；n = 8）在温带（TEMP；22°C）和炎热（HEAT；35°C）条件下静息及运动时的反应。
参与者在每种条件下进行三个阶段的骑行试验，强度分别为乳酸阈1的90%、135%和180%（总计52.5分钟）。连续记录心率（HR）和核心体温（T），而血压（BP）、主观用力程度分级（RPE）、血乳酸[La]和皮肤血流量（BF）每7.5分钟记录一次。
在TEMP（p = 0.03）和HEAT（p < 0.01）试验前，女性口服避孕药组的基线T分别高于自然月经女性组（37.5±0.2、37.6±0.3°C对比37.2±0.2、37.0±0.4°C）。在两项试验的前22.5分钟，这种差异仍然存在（p≤0.05），之后未发现组间差异（p > 0.05）。自然月经女性组在HEAT试验中，BF从7.5分钟开始趋于平稳，而女性口服避孕药组的BF在趋于平稳前增加了15.0分钟（p = 0.02）。在两项试验之前或整个过程中，HR、BP或血[La]均无组间差异（p > 0.05）。在HEAT试验中，女性口服避孕药组的RPE值高于自然月经女性组（p≤0.04），在第3阶段结束时分别报告为8±1和6±2。
女性口服避孕药组在两项试验结束时的T与自然月经女性组相当，但在HEAT试验中BF反应延长且RPE升高。使用口服避孕药的女性中观察到的BF和RPE变化可能对炎热条件下的运动耐力有影响。
