Aquatic exercise in hypobaric hypoxic environment for the lifestyle-related disease improvement

本研究旨在建立一种有益于改善生活方式相关疾病的运动疗法，探讨低压低氧环境下水中运动对心血管反应、糖和脂肪代谢的影响。中年组D（n=5）进行强度约为50%VO2max的水中运动，每次30 min，连续4周。A、B和D暴露于海拔2000 m的低氧条件下，C暴露于海拔2500 m的低氧条件下，每次暴露2.5小时。训练频率A组每周4次，B、C、D组每周3次。在训练前和训练后测定50%VO_2max运动时的VO_2max和心率（HR）、每搏输出量（SV）、心输出量（CO）、收缩压（SBP）、舒张压（DBP）和平均血压（MBP）等心血管反应，并在训练4周后进行比较。VO_2max在各组均无明显变化。在中等强度运动时心血管反应中，B和D无明显变化。另一方面，SV和CO在A和C中显著增加。此外，在A和C中观察到DBP和MBP显著降低。口服葡萄糖耐量试验后，曲线下面积和血胰岛素浓度在120分钟时仅在C组显著降低。在血脂方面，A、B组总胆固醇和低密度脂蛋白显著降低，而C、D组无明显变化。在A、B和C中观察到皮褶厚度显著降低，但D中未观察到。总之，我们的研究结果表明，在低压低氧环境中的水上运动会更有效地诱导心血管功能，葡萄糖和脂肪代谢的有益变化。这些新的发现将打开积极的可能性，利用缺氧与运动的预防和临床治疗的生活方式相关的疾病。

Present study aimed to establish a beneficial exercise therapy for lifestyle-related disease improvement, determining the effects of aquatic exercise in hypobaric hypoxic environment gives on cardiovascular response, glucose and fat metabolism.Healthy 3 young adult groups, A (n=6), B (n=6), C (n=6), and middle-aged group D (n=5) performed an aquatic exercise at the intensity of around 50%VO2max for 30 min/session, for 4 weeks. A, B and D were exposed to hypoxic condition corresponding to 2000m and C was exposed to 2500m above sea level for 2.5hours/session. The training frequency was 4 times/week in A and 3 times/week in B, C and D. Before and after the training period, VO_2max and cardiovascular responses such as heart rate (HR), stroke volume (SV), cardiac output (CO), and systolic (SBP), diastolic (DBP) and mean blood pressure (MBP) during cycling exercise at the intensity of 50%VO_2max, which was determined before the training, were measured.After the 4 weeks of training, VO_2max did not change significantly in all groups. In cardiovascular responses during the moderate exercise, no significant changes were observed in B and D. On the other hand, SV and CO in A and C significantly increased. In addition, a significant decrease was observed in DBP and MBP in A and C. Also, after the oral glucose tolerance test, under-curve area and blood insulin concentration by 120 min were significantly reduced only in C. In blood lipid, total cholesterol and LDL were significantly decreased in A and B, but not in C and D. A significant decrease was observed in skinfold thickness in A, B and C, but not D. Taken all, our results revealed that an aquatic exercise in hypobaric hypoxic environment would induce more effectively the beneficial changes in cardiovascular function, glucose and fat metabolism. These new findings would open the positive possibilities of utilizing hypoxia with exercise for prevention and clinical treatment of lifestyle-related disease.