ABSTRACT
OBJECTIVE: To investigate the relationship among perceived stress,sleep and fatigue status; and to analyze the effect of sleep status in mediating and regulating perceived stress and fatigue status in soldiers that were acutely exposed to high altitude for the first time. METHODS: A total of 700 soldiers that were acutely exposed to high altitude for the first time were investigated with convenient sampling. They were evaluated using Perceived Stress Scale,Sleep Status Self-evaluation Test,and Fatigue Scale-14. The mediating effect was analyzed by structural equation model,and the moderating effect was analyzed by hierarchical regression analysis. RESULTS: The total score of fatigue among soldiers that often took part in recreational activities was significant lower than that who did not( P < 0. 01). The total score of fatigue among soldiers that had training injury was significant higher than that who had not( P < 0. 01). The total score of fatigue among soldiers that had high training expectations was significant higher than that that didn't have high training expectations( P < 0. 01). Sleep status,sense of overload and training expectations had remarkable predicting effect on fatigue status among soldiers that were acutely exposed to high altitude for the first time( P < 0. 01). Sleeping status has a complete mediating effect on the sense of prediction,sense of overload and fatigue status( P < 0. 01),and has a moderating effect on the sense of control,sense of overload and fatigue status( P < 0. 01). CONCLUSION:s Perceived stress and sleeping status had close relationship with fatigue status among soldiers that were acute exposed to high altitude for the first time. Sleeping status has intermediary and regulating effect between senses of overload and fatigue state.
ABSTRACT
Objective To investigate the effect of plateau training on military operation ability ,evaluate the real situa-tion of combat forces on the plateau , and to provide data for effectively improving the combat effectiveness of the army stationed on the plateau .Methods According to the standards , the levels of high altitude acclimatization , physical work capacity (VO2max, PWC170) and mental work capacity (digit span, digit symbol, pursuit aiming and visual reaction time) were measured to assess the military operation ability of plateau training troops , including troops that entered the plateau from the plain(plateau-entering troops), troops stationed on the plateau (plateau troops) and troops stationed in the plain ( plain troops ) .Results The troops on the plateau all reached basic acclimatization .The aerobic capacities of these three types of troops were of the standard medium level , and the maximum oxygen uptake ( VO2max ) of the plain troops was greater than that of that of plateau-entering troops(P<0.01), and the VO2max of the plateau troops was greater than that of plateau-entering troops(P<0.01).Compared with the plain troops, the VO2 max and PWC170 of the plateau-entering troops decreased by 25.7%and 27.7%respectively.There was no significant difference in the digit span , digit symbol, pursuit aiming between these 3 kinds of troops , but the visual response of the plateau-entering troops was prolonged ( P<0.01), while the pursuit aiming of the plateau troops was lower than that of the plateau-entering troops(P <0.05). Conclusion Acclimatization-promoting measures and plateau training can contribute to high altitude acclimatization formation, but cannot overcome the objective adverse effects of the plateau on physical fitness .Two months of plateau training fails to improve physical fitness.Therefore, special attention should be paid to the research on scientific and effective measures to improve physical fitness on the plateau .