Effects of exercising in a hot and humid environment on blood urea,blood lactic acid and electrolyte of the human body
The authors tried to reveal the adaptation of the body exercising in a hot and humid environment through an experiment studying the characteristics of changing of blood constituents of the body in a hot and humid envi-ronment,so as to provide corresponding theoretical criteria for training.The authors selected 30 males students with an average age of(21.3±1.1) randomly from a university.The experiment was done in the hot and humid environ-ment training laboratory of Second Military Medical University,where the ambient temperature was controlled to 39 ℃,the relative humidity was 80%.The experiment lasted 9 d,which were divided into a testing stage and a training stage;at the testing stage,a 12 min speed bike test was run 1 d before and after training respectively;before and after the two tests,venous blood was taken from upper limbs(immediately after rectal temperature index was tested);the cycle of the training stage is 7 d,the exercising loads were 15 min of hand free walking on a treadmill,15 min of resistance free exercising on a model BC4730-52 EVERE speed bike,15 min of exercising on a model BC8500 EVERE speed bike which was adjusted to 10LEVEL-280WATT/H.The results showed the followings: as compared with the results before the first and second tests,blood urea(BU),lactic acid(La), and after the two tests increased significantly(P0.05), decreased significantly(P0.05); increased significantly(P0.05) after the second test;after 7 days of heat acclimatization training,as compared with the results before the first test,BU and before the second test increased significantly(P0.05),La concentration decreased signifi-cantly(P0.05);as compared with the results after the first test,BU,, and after the second test in-creased significantly(P0.05).The results indicated the followings: after 7 d of intermittent,repeated heat exposure exercising,the body's protein metabolism and energy supply decreased somewhat;La removing ability was en-hanced;various indexes in blood electrolyte changed to different extents,but they were all in range of normal physiology and the range tolerable to the human body;and the exercising ability and self perception were improved,which indicates that heat acclimatization training is conducive for the body to establish a new dynamic stereotype of thermal reaction.