Effects Of Simulated Living High-Training Low On The Maintainance Of Hbmass After Altitude Training

Objective: To provide experimental evidence for maintaining the beneficial effects of altitude training, we investigate the time course of the decay of the hemoglobin mass(Hbmass) and the maintenance of the Hbmass by simulated “Living-High-Training-Low” after a 3-week altitude training program, during which the related biological mechanisms has been studied and discussed.Methods: 18 college athletes of Mixed Martial Arts(MMA) from Beijing Sport University were recruited for this study. All the subjects lived and trained at 2400m(Lijiang, Yunnan) for 3 weeks, and then they descended to sea level(Beijing) and took part in a 20-day subsequent training program after their altitude training. Before the subsequent training began, subjects were divided into 2 groups: the Living Low-Training Low group(LL group; n=9), in which all the subjects living and training in the normal sea level environment; and the Living High-Training Low group(HL group; n=9), in which all the subjects living at 2800 m simulated altitude for 12h/day and training in the same environment with the same coach and training plan as the LL group. With one week prior to altitude training, Hbmass was measured twice for the baseline value using the optimized CO rebreathing method, and venous blood samples were collected to test serum erythropoietin(EPO), serum ferritin(Fer), serum haptoglobin(Hpt), serum free hemoglobin(FHb), serum total bilirubin(TBil), serum direct bilirubin(DBil), and indirect bilirubin(IBil). Thereafter, all the parameters were tested on day 2, 6, 9, 15, 21 after altitude training, and an additional measurement for Hbmass was performed on day 12 after altitude training.Results: After the altitude training, all the subjects experienced a ~6% increase(p<0.01) in Hbmass. In LL group, Hbmass was maintained at a higher level(p<0.01) than baseline value on day 2 and day 6, but returned to baseline on day 9 and remained at the baseline level thenceforth; rHbmass(relative Hbmass; Hbmass/body mass, g/kg) represented the same time course as the Hbmass; EPO level decreased significantly on day 2 and day 6(p<0.01) and then returned to the baseline value; Hpt and FHb remained stable throughout the study. In HL group, Hbmass was significantly higher than baseline on day 2 and day 6(p<0.05), then decreased a bit but still higher than the baseline value on day 9 and day 12(p<0.05), and returned to baseline level thereafter; rHbmass was maintained at a higher level(p<0.05) than the baseline value since the descent from altitude, and significantly higher than that in LL group in general; EPO decreased significantly on day 2(p<0.05), but returned to and remained at baseline thereafter, while the level of EPO was significantly higher compared to that in LL group on day 6(p<0.05); Hpt and FHb remained stable throughout the study, and no difference was detected when compared with the same time point in LL group respectively.Conclusions: A 3 – week altitude training program significantly increases Hbmass. Although the gained Hbmass would be maintained just for about one week and then decrease to baseline, simulated LHTL after altitude training could prevent the decreasing trend of EPO and restore EPO from suppressed state to normal state quickly so that help to maintain the high level of hemoglobin.