吸气肌训练对常氧和低氧条件下运动呼吸功能的影响

The Effects of Inspiratory Muscle Training on Respiration Function at Hypoxia and Normoxia

目的:检测吸气肌训练(IMT)对常氧和低氧条件下运动效果的影响;方法:15名受试者用呼吸肌训练仪进行为期4周的训练,其中,对照组8人,采用15%PImax(最大吸气口腔压力);训练组7人,采用50%PImax。训练前后,在低氧和常氧条件下分别进行85%V.O2max的跑台力竭测试及功能测试;结果:IMT组PImax增加24.5%±3.1%。所有条件下力竭时间均未见改变。IMT组在常氧和低氧运动后呼吸肌疲劳均减少10%(P<0.05);在低氧条件下运动,V.O2减少8%～12%(P<0.05),心输出量减少14%±2%,通气量减少25%±3%;动脉血氧饱和度和肺扩散能力分别增加了4%±1%和22%±3%;结论:IMT可以明显改善低氧条件下运动的呼吸功能。

The purpose of this study was to determine the effects of inspiratory muscle training （IMT） on exercise at hypoxia（H） and normoxia （N）. Four-week IMT program was implemented with 15 healthy subjects using an inspiratory muscle training machine set at either 15 % （ C： n = 8 ） or 50 % （ IMT ： n = 7 ） maximal inspiratory mouth pressure （Plmax）. Two treadmill tests （85 % VO2 max） to exhaustion and measurement of function were completed before and after training in H and N. Significant increasing of 24. 5 % ±3. 1% in Plmax was seen in the IMT group. Time to exhaustion remained unchanged in all conditions. Inspiratory muscle fatigue following exercise was reduced 10% （P〈0.05） in IMT after both normoxia and hypoxia. During hypoxia training, IMT reduced （P〈 0. 05） VO2 by 8% ± 12%, cardiac output by 14 %± 2 %, ventilation by 25% ＋ 3 %, but increased arterial oxygen saturation by 4 % ± 1% and lung diffusing capacity by 22%±3 %. These data suggest that IMT significantly improves functional physiologic measurement at hypoxic exercise.