Eynan Mirit, Ertracht Offir, Yehezkel Shiran, Svidovsky Paulina, Ne'eman Frida, Arieli Ran
Israel Naval Medical Institute, IDF Medical Corps, Haifa, Israel.
Aviat Space Environ Med. 2010 Jan;81(1):8-14. doi: 10.3357/asem.2578.2010.
Contradictory results have been obtained regarding the beneficial effect of hyperbaric oxygen (HBO) on exercise performance. The purpose of this study was to investigate the effect of different combinations of pressure and time in hyperoxia on the energetic efficiency of trained and sedentary rats.
At the end of the training period, rats were exposed to one of three protocols: 1) 100% normobaric oxygen for 24 h; 2) HBO at 2 ATA for 4 h; 3) HBO at 2.5 ATA for 6 h. After the hyperoxic exposures, V(O2max) was evaluated and compared with preexposure values.
The slope of the linear section of the oxygen consumption-velocity curve in the trained rats was significantly steeper after exposure to either 100% normobaric oxygen for 24 h or HBO at 2 ATA for 4 h than before the exposure. The opposite was found for the sedentary rats. After exposure to HBO at 2.5 ATA for 6 h, the slope of the oxygen consumption-velocity curve in the trained rats did not differ from the pre-exposure slope. However, the highest velocity these rats reached was lower than their maximum velocity before this exposure. In the sedentary rats, the slope of the oxygen consumption-velocity curve was found to be steeper after the 2.5 ATA exposure compared with the preexposure slope.
Our results suggest that exposure to 100% normobaric oxygen for 24 h and HBO at 2 ATA for 4 h induces a reduction in the energetic efficiency of trained rats, but improves energetic efficiency in sedentary rats.
关于高压氧（HBO）对运动表现的有益作用，已获得相互矛盾的结果。本研究的目的是调查高氧环境下不同压力和时间组合对训练有素的大鼠和久坐不动的大鼠能量效率的影响。
在训练期结束时，将大鼠暴露于以下三种方案之一：1）100%常压氧24小时；2）2个绝对大气压的高压氧4小时；3）2.5个绝对大气压的高压氧6小时。高氧暴露后，评估最大摄氧量（V(O2max)）并与暴露前的值进行比较。
训练有素的大鼠在暴露于100%常压氧24小时或2个绝对大气压的高压氧4小时后，耗氧速度曲线线性部分的斜率比暴露前明显更陡。久坐不动的大鼠则相反。在暴露于2.5个绝对大气压的高压氧6小时后，训练有素的大鼠耗氧速度曲线的斜率与暴露前的斜率没有差异。然而，这些大鼠达到的最高速度低于此次暴露前的最大速度。在久坐不动的大鼠中，发现暴露于2.5个绝对大气压后，耗氧速度曲线的斜率比暴露前更陡。
我们的结果表明，暴露于100%常压氧24小时和2个绝对大气压的高压氧4小时会导致训练有素的大鼠能量效率降低，但会提高久坐不动的大鼠的能量效率。
