Bonne Thomas Christian, Jeppesen Jan Sommer, Bejder Jacob, Breenfeldt Andersen Andreas, Olsen Niels Vidiendal, Huertas Jesús Rodríguez, Nordsborg Nikolai Baastrup
Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark.
Section of Sport Science, Department of Public Health, Arhus University, Aarhus, Denmark.
Sleep Breath. 2023 Aug;27(4):1611-1618. doi: 10.1007/s11325-022-02713-z. Epub 2022 Sep 30.
We evaluated whether or not changes in body composition following moderate hypoxic exposure for 4 weeks were different compared to sea level exposure.
In a randomized crossover design, nine trained participants were exposed to 2320 m of altitude or sea level for 4 weeks, separated by > 3 months. Body fat percentage (BF%), fat mass (FM), and fat-free mass (FFM) were determined before and after each condition by dual X-ray absorptiometry (DXA) and weekly by a bioelectrical impedance scanner to determine changes with a high resolution. Training volume was quantified during both interventions.
Hypoxic exposure reduced (P < 0.01) BF% by 2 ± 1 percentage points and increased (P < 0.01) FFM by 2 ± 2% determined by DXA. A tending time × treatment effect existed for FM determined by DXA (P = 0.06), indicating a reduced FM in hypoxia by 8 ± 7% (P < 0.01). Regional body analysis revealed reduced (P < 0.01) BF% and FFM and an increased (P < 0.01) FFM in the truncus area. No changes were observed following sea level. Bioelectrical impedance determined that BF%, FM, and FFM did not reveal any differences between interventions. Urine specific gravity measured simultaneously as body composition was identical. Training volume was similar between interventions (509 ± 70 min/week vs. 432 ± 70 min/week, respectively).
Four weeks of altitude exposure reduced BF% and increased FFM in trained individuals as opposed to sea level exposure. The results also indicate that a decrease in FM is greater at altitude compared to sea level. Changes were specifically observed in the truncus area.
我们评估了4周中度低氧暴露后身体成分的变化与海平面暴露相比是否存在差异。
采用随机交叉设计，9名受过训练的参与者分别在海拔2320米或海平面环境下暴露4周，两次暴露间隔超过3个月。在每种环境暴露前后，通过双能X线吸收法（DXA）测定体脂百分比（BF%）、脂肪量（FM）和去脂体重（FFM），并每周使用生物电阻抗扫描仪进行测定，以高分辨率确定变化情况。在两种干预期间均对训练量进行了量化。
通过DXA测定，低氧暴露使BF%降低了2±1个百分点（P<0.01），FFM增加了2±2%（P<0.01）。通过DXA测定的FM存在时间×治疗效应趋势（P=0.06），表明低氧环境下FM降低了8±7%（P<0.01）。局部身体分析显示，躯干区域的BF%和FFM降低，FFM增加（P<0.01）。海平面暴露后未观察到变化。生物电阻抗测定显示，BF%、FM和FFM在两种干预之间未显示出任何差异。与身体成分同时测量的尿比重相同。两种干预之间的训练量相似（分别为509±70分钟/周和432±70分钟/周）。
与海平面暴露相比，4周的海拔暴露使受过训练的个体BF%降低，FFM增加。结果还表明，与海平面相比，海拔高度下FM的降低幅度更大。在躯干区域特别观察到了变化。
