Miranda Hurtado Martin, Meza Valladares Cristian, Eblen-Zajjur Antonio, Rodriguez-Fernandez Maria
1 Nursing School, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile.
2 Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Catolica de Chile, Santiago, Chile.
J Altern Complement Med. 2019 Apr;25(4):398-405. doi: 10.1089/acm.2018.0261. Epub 2019 Jan 30.
Main cardiovascular parameters such as heart rate (HR), blood pressure, and myocardial oxygen consumption (MOC) are tightly regulated by a multifactorial, nonlinear control system. Increased HR because of physical activity is often accompanied by an increase in blood pressure. Postural changes have an effect on the baroreceptors, and stretching exercises and isometric contractions modulate muscle mechanoreceptors eliciting increases in blood pressure. However, a hot environment increases the core temperature inducing vasodilation and plasma volume changes that might contribute to a drop in blood pressure. During the practice of Bikram yoga, all these factors converge and little is known about the resulting changes in blood pressure and MOC.
Sixteen apparently healthy female volunteers, regular practitioners of Bikram yoga, were evaluated during a 90 min session. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured immediately after each posture and HR was measured continuously during the practice.
HR and estimated MOC increased significantly over baseline during the exercise (+62.3% and +63.6%, respectively). HR mean value across the entire Bikram yoga session was 126.6 ± 14.3 bpm reaching a maximum of 168.1 ± 20.2 bpm. SBP was not significantly increased over baseline at any time during the practice with a mean value of 117.0 ± 10.1 mmHg and DBP was significantly decreased over baseline most of the time (-10.1%, mean 71.2 ± 7.3 mmHg) with particular decline toward the end of the practice during the floor postures.
DBP during the practice of Bikram yoga was significantly different from that previously reported for nonheated Hatha yoga for normotensive subjects. Further studies evaluating the same group at both conditions are needed to better characterize the magnitude of the changes in HR, SBP, DBP, and MOC.
主要心血管参数，如心率（HR）、血压和心肌耗氧量（MOC），由一个多因素、非线性控制系统严格调节。因体力活动导致的心率增加通常伴随着血压升高。体位变化会影响压力感受器，伸展运动和等长收缩会调节肌肉机械感受器，从而引起血压升高。然而，炎热环境会使核心体温升高，导致血管舒张和血浆容量变化，这可能会导致血压下降。在高温瑜伽练习过程中，所有这些因素相互交织，而关于由此导致的血压和心肌耗氧量变化知之甚少。
对16名明显健康的女性志愿者进行评估，她们均为高温瑜伽的定期练习者，评估过程持续90分钟。在每个体式结束后立即测量收缩压（SBP）和舒张压（DBP），并在练习过程中持续测量心率。
运动过程中心率和估计的心肌耗氧量较基线水平显著增加（分别增加62.3%和63.6%）。整个高温瑜伽练习过程中的平均心率为126.6±14.3次/分钟，最高达到168.1±20.2次/分钟。练习过程中，收缩压在任何时候均未较基线水平显著升高，平均值为117.0±10.1mmHg，舒张压在大多数时间较基线水平显著下降（下降10.1%，平均为71.2±7.3mmHg），尤其是在练习接近尾声的地面体式阶段下降更为明显。
高温瑜伽练习过程中的舒张压与之前报道的正常血压受试者进行的非热哈他瑜伽练习中的舒张压显著不同。需要进一步研究在两种条件下对同一组受试者进行评估，以更好地描述心率、收缩压、舒张压和心肌耗氧量变化的幅度。
