Effect of low concentration preoxygenation on the new recruits arriving at a height of 3651m above sea level

Objective To evaluate the effect of low-concentration preoxygenation on physical work capacity with a heart rate of 170 beat per minute (PWC170) in recruits arrived on Qinghai-Tibet Plateau (3651m height above sea level), and investigate the possible correlation between new recruits' coping style and physical work capacity. Methods Thirty-nine recruits coming from plains (799m or 620m height above sea level) were involved in our study. They were randomly divided into 3 groups: experimental group I (n=12), experimental groupⅡ (n=12), and control group (n=15). The group I had 1L/min low concentration preoxygenation for 30min, and groupⅡ had 2L/min for 30min, once a day for 3 days. No preoxygenation in control group. The new recruits's PWC170 values were measured by stepping stairs for evaluating their physical ability, and the new recruits's coping responses were investigated with "Physical Training Coping Scale", and then those data compared with these of 98 soldiers stationed in Tibet (senior soldier group, stationed in Tibet for at least 2 years). Results Each basic PWC170 values showed no significant diffierence between group Ⅰand Ⅱ (P>0.05). Each basic PWC170 was significantly higher in the experimental groups Ⅰand Ⅱthan in control group (P0.05). Correlation analysis showed that there was a significant positive correlation between the "active response" factor and basic PWC170 value, and between "emotional management" factor and PWC170 value on second day between the two experimental groups (r=0.329 and 0.344 respectively, P