Schaumberg Mia Annalies, Stanley Jamie, Jenkins David G, Hume Emily A, Janse de Jonge Xanne A K, Emmerton Lynne M, Skinner Tina L
School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia.
Sunshine Coast Health Institute, Birtinya, QLD, Australia.
Front Physiol. 2020 Jun 12;11:629. doi: 10.3389/fphys.2020.00629. eCollection 2020.
Oral contraceptive (OC) use influences peak exercise responses to training, however, the influence of OC on central and peripheral adaptations to exercise training are unknown. This study investigated the influence of OC use on changes in time-to-fatigue, pulmonary oxygen uptake, cardiac output, and heart rate on-kinetics, as well as tissue saturation index to 4 weeks of sprint interval training in recreationally active women.
Women taking an oral contraceptive (OC; = 25) or experiencing natural menstrual cycles (MC; = 22) completed an incremental exercise test to volitional exhaustion followed by a square-wave step-transition protocol to moderate (90% of power output at ventilatory threshold) and high intensity (Δ50% of power output at ventilatory threshold) exercise on two separate occasions. Time-to-fatigue, pulmonary oxygen uptake on-kinetics, cardiac output, and heart rate on-kinetics, and tissue saturation index responses were assessed prior to, and following 12 sessions of sprint interval training (10 min × 1 min efforts at 100-120% PPO in a 1:2 work:rest ratio) completed over 4 weeks.
Time-to-fatigue increased in both groups following training ( < 0.001), with no difference between groups. All cardiovascular on-kinetic parameters improved to the same extent following training in both groups. Greater improvements in pulmonary oxygen up-take kinetics were seen at both intensities in the MC group ( < 0.05 from pre-training) but were blunted in the OC group ( > 0.05 from pre-training). In contrast, changes in tissue saturation index were greater in the OC group at both intensities ( < 0.05); with the MC group showing no changes at either intensity.
Oral contraceptive use may reduce central adaptations to sprint interval training in women without influencing improvements in exercise performance - potentially due to greater peripheral adaptation. This may be due to the influence of exogenous oestradiol and progestogen on cardiovascular function and skeletal muscle blood flow. Further investigation into female-specific influences on training adaptation and exercise performance is warranted.
口服避孕药（OC）的使用会影响训练后的运动峰值反应，然而，OC对运动训练的中枢和外周适应性的影响尚不清楚。本研究调查了在休闲活动女性中，使用OC对冲刺间歇训练4周后的疲劳时间、肺摄氧量、心输出量、心率动力学以及组织饱和度指数变化的影响。
服用口服避孕药（OC组；n = 25）或处于自然月经周期（MC组；n = 22）的女性完成递增运动试验至自愿疲劳，随后在两个不同时间进行方波阶跃转换方案，分别进行中等强度（通气阈值时功率输出的90%）和高强度（通气阈值时功率输出增加50%）运动。在4周内完成12次冲刺间歇训练（以1:2的工作:休息比例，在100 - 120%个人最佳功率下进行10分钟×1分钟的努力）之前和之后，评估疲劳时间、肺摄氧量动力学、心输出量、心率动力学以及组织饱和度指数反应。
两组训练后疲劳时间均增加（P < 0.001），组间无差异。两组训练后所有心血管动力学参数均有同等程度改善。MC组在两种强度下肺摄氧量动力学的改善更大（与训练前相比P < 0.05），而OC组则不明显（与训练前相比P > 0.05）。相反，OC组在两种强度下组织饱和度指数的变化更大（P < 0.05）；MC组在两种强度下均无变化。
使用口服避孕药可能会降低女性对冲刺间歇训练的中枢适应性，而不影响运动表现的改善——这可能是由于更大的外周适应性。这可能是由于外源性雌二醇和孕激素对心血管功能和骨骼肌血流的影响。有必要进一步研究女性特有的对训练适应性和运动表现的影响。
