The Influence Of HiHiLo On Acid-base Balance And Relative Transporters Capacities In Blood

Living high-training low (HiLo)is frequently used by competitive athletes to improve sea-level performance. It can improve the exercise abilities, such as VO2max and running speed. Acclimatization to high altitude results in central and peripheral adaptations that improve oxygen delivery and utilization. Moreover, hypoxic exercise may increase the training stimulus, thus magnifying the effects of endurance training.Living high-training low plus exercise at moderate altitud(eHiHiLo) is used to get better effects. Acid-base homeostasis and its control system seem to be one of the mechanisms of this improvement. The present study was designed to test HiHiLo's effects and its mechanism about acid-base balance.16 male well-trained football players were divided two groups: contrast group (C) and HiHiLo group (H). H group stayed at hypoxic training camp for 10 hours per day for 4 weeks. Every week H group performed 40min cycle exercise twice, the intensity was 72%VO2max. The C group performed the same exercise at sea level at 80%VO2max. The training plan was same in two groups at sea level. Each subject performed incremental cycling to exhaust to determine the VO2max before and after 4 weeks. 7ml blood sample were collected before and after the fifth grade load (210W) for analysis blood gases. Plasma volume, blood volume, red cell mass volume and mRNA were analyzed before testing. The results showed that:1. There was no significant difference in Maximal oxygen uptake among the groups, and the load of anaerobic threshold increased significantly after the altitude training camp only in the H group.2. RBC, Hb and Hct did not change in any group during 4 wk of supervised training at sea level or in altitude training camp. However, ret and ret% increased significantly only in the H group after the altitude training camp. It means the enhanced capabilities of blood regenerations reached.3. The HCO3-and base excess decreased significantly after exercise in both group. There was no significantly difference between two groups and before and after 4 weeks. The lactate concentration decreased in both group after 4 weeks training, the significantly depress could be seen in H group, it means the improvement of exercise abilities. In H group, there was no change in total extracellular HCO3-(βfor HCO3- ), but the non- HCO3-(βforΔLac/ΔpH )dependent pH defence against lactic acidosis was increased significantly. It means the dynamic buffer capacity was increased.4. The mRNA of MCT1 (lactate-H+ co-transporter) had no change compared with 4 weeks before, but AE1 (Cl-- HCO3- exchanger) increased significantly, the increases level of AE1 would benefit to the uptake and release of O2 and CO2 in erythrocyte.In conclusion, 4 weeks of HiHiLo training results in improvements of the aerobic performance in football players. And HiHiLo can enhance the capabilities of blood regenerations and dynamic buffer capacity in blood. The beneficial effects of HiHiLo can be inferred from the upregulated mRNA of AE1.