Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA 01760, USA.
Med Sci Sports Exerc. 2009 Jun;41(6):1317-25. doi: 10.1249/MSS.0b013e3181954601.
This study examined the effect of 1 wk of normobaric intermittent hypoxic exposure (IHE) combined with exercise training on endurance performance at a 4300-m altitude (HA).
Seventeen male lowlanders were divided into an IHE (n = 11) or SHAM (n = 6) group. Each completed cycle endurance testing consisting of two 20-min steady state (SS) exercise bouts (at 40% and 60% V O2peak) followed by a 10-min break and then a 720-kJ cycle time trial at HA before IHE or SHAM treatment (Pre-T). IHE treatment consisted of a 2-h rest at a PO2 of 90 mm Hg followed by two 25-min bouts of exercise at approximately 80% of peak HR at a PO2 of 110 mm Hg for 1 wk in a hypoxia room. SHAM treatment was identical except that the PO2 was 148 mm Hg for both rest and exercise. After IHE or SHAM treatment (Post-T), all completed a second cycle endurance test at HA. HR, arterial oxygen saturation (SaO2), and RPE were obtained from the 10th to the 15th minute during the two SS exercise bouts and every 5 min during the time trial.
Seven volunteers in the IHE group could not finish the 720-kJ time trial either at Pre-T or at Post-T. Time trial analysis was limited, therefore, to the time to reach 360 kJ (halfway point) for all volunteers. From Pre-T to Post-T, there was no improvement in time trial performance (min +/- SE) in the IHE (62.0 +/- 4.8 to 63.7 +/- 5.2) or SHAM (60.9 +/- 6.3 to 54.2 +/- 6.8) group. There was no change from Pre-T to Post-T in HR, SaO2, and RPE during the two SS exercise bouts or time trial in either group.
One week of IHE combined with exercise training does not improve endurance performance at a 4300-m altitude in male lowlanders.
本研究探讨了 1 周常压间歇性低氧暴露（IHE）联合运动训练对 4300 米海拔（HA）耐力表现的影响。
17 名男性低地人被分为 IHE（n=11）或 SHAM（n=6）组。每组均完成两次 20 分钟的稳态（SS）运动测试，随后休息 10 分钟，然后在 IHE 或 SHAM 治疗（Pre-T）前在 HA 进行 720-kJ 计时赛。IHE 治疗包括在 PO2 为 90 mmHg 下休息 2 小时，然后在缺氧室中以 PO2 为 110 mmHg 下进行两次 25 分钟的运动，运动强度约为峰值 HR 的 80%，持续 1 周。SHAM 治疗相同，只是休息和运动时的 PO2 均为 148 mmHg。在 IHE 或 SHAM 治疗（Post-T）后，所有受试者均在 HA 进行第二次计时赛。在两次 SS 运动期间，从第 10 分钟到第 15 分钟，以及在计时赛期间每 5 分钟，均记录 HR、动脉血氧饱和度（SaO2）和 RPE。
IHE 组的 7 名志愿者在 Pre-T 或 Post-T 时均无法完成 720-kJ 计时赛。因此，仅对所有志愿者的 360 kJ（中点）到达时间进行了计时赛分析。从 Pre-T 到 Post-T，IHE（62.0±4.8 至 63.7±5.2）或 SHAM（60.9±6.3 至 54.2±6.8）组的计时赛成绩均无改善。在两次 SS 运动或任何一组的计时赛中，从 Pre-T 到 Post-T，HR、SaO2 和 RPE 均无变化。
1 周的 IHE 联合运动训练不能提高男性低地人的 4300 米海拔耐力表现。
