The Variation Of SpO2 During HiHiLo And Effectiveness Of Training

Objective:This paper analyzed the changes of SpO2 after 10h exposure to hypoxia and during acute hypoxic exercise in order to explore the correlation between SpO2 and effectiveness of HiHiLo and discuss the feasibility that the SpO2 is used as a prediction index of hypoxic training effectiveness.Methods:The subjects were 71 male students from the department of physical education in Beijing Sport University.The subjects were exposed in hypoxia(02%:14.3%--14.8%equivalent to the altitude of 2800--3000m) 10 hours(21:00--7:00) everyday lasting for 30 days.Besides participating the routine training at sea level,the subjects completed three training sections(bicycle ergometer exercise at the intensity of 75%V02maxwith the cadence of 60 rev/min lasting for 30 min) in hypoxia every week.During the hypoxic exercise the SpO2 was controlled at 90±2(%) by adjusting the oxygen concentration and the exercise load.During the HiHiLo,the VO2max throughout the grade exercise test at sea level,the rest SpO2 collected in the morning during hypoxia exposure,the indices of blood and the changes in SpO2 during hypoxia exercise were recorded.Results:1.During the 1 month period of HiHiLo,the peak values of RBC,Hb and Hct were appear on the 16th day and leved off afterward.2.The VO2max of the subjects increased by 5.97%after the HiHiLo.The augmentation of HR when the subjects completed the same exercise reduced significantly compared with the values before HiHiLo.It indicated that the the aerobic exercise capacity improved obviously.3.The lowest value of SpO2 appeared after 10h exposure to hypoxia.The SpO2 increased as the accumulation of exposure time;however,the SpO2 was still significantly lower than that in normoxia at the end of HiHiLo. 4.During acute hypoxic exercise,the SpO2 was at a relatively low level through the whole exercise,and didn' t recover at 5th min of recovery phase.As the accumulation of exposure time,the adaptation occurred. The decrease of SpO2 and the augmentation of HR when the subjects completed the exercise reduced significantly compared with the values before HiHiLo.The recovery phase shortened obviously.5.The changes of SpO2 and Hb showed large individual variability. Subjects whose SpO2 decreased the more significantly after the acute hypoxia exposure showed the more significant increase in blood indices after HiHiLo and the peak value appeared earlier than other subjects. The changes of rest SpO2 recorded in the morning after acute hypoxia exposure can be used as a prediction index for the changes of blood indices during the process of HiHiLo.6.There was certain correlation between SpO2 obtained in the hypoxic exercise after acute hypoxia exposure and blood indices,but there was no statistical significance at any test point btween the two groups. Whether the exercise SpO2 after acute hypoxia exposure can be used as prediction index needs to be further investigated.7.The SpO2 obtained at rest and during exercise respectively after acute hypoxia exposure were not correlated with VO2max.Conclusion:HiHiLo can promote the production of RBC,Hb efficaciously and improve the capacity of aerobic metabolism by improving the capacity of oxygen transportation of blood.The changes of SpO2 after 10h exposure to hypoxia indicate the ability of individual to adapt to hypoxia.The SpO2 can be used as a prediction index of changes in blood indices during HiHiLo.