ABSTRACT
Objective To observe the effect of a repeated-sprint training on the speed-endurance of basketball players in a hypoxia environment.Methods Sixteen basketball players were divided into a hypoxiagroup and a normoxia group which had 8 persons each group.The 2 groups separatelyhad a repeated-sprint training with anaerobic power bicycles in a simulatedhypoxic environment at the altitude of 3000 meters and a normoxia environment for 4 weeks(twice a week).Before and after the training,the two groups of subjects had a shuttle run testing and a Wingateanaerobic powertestingin a normoxia environment.Then their blood were collected and measured the blood lactate level at the point-intime of after the shuttle run,3 min later,5 min later,7 min later,and 9 min later.Recorded the result of the shuttle run,the relative average power of the Wingateanaerobic powertesting,and carried on a statistic analysis of the data.Results Comparing with the performance of the shuttle run before the training,the performance of the 2 groups was improved obviously after the four-week-long training (P＜0.05).But there was no significant difference between the 2 groups(P＞0.05).The rate of blood lacticacid clearance in the hypoxia group was higher than that in the normoxia group,and there was a significant difference at 7 min (P＜0.01).The relative average power of the hypoxia group had a significant improvement(P＜0.05),while the normoxia group had no significant change(P＞0.05).There was no significant difference of the relative average power between the two groups.Conclusion Repeatedsprint training can improve basketball players' speed-endurance.Repeated-sprint training in a hypoxic environment can effectively improve basketball players' ability of reducing blood lactate in their body,and the improvement of this aerobic ability can help athletes to have a better performance in competitions.
ABSTRACT
Objective To investigate the distribution characteristics of (CAG)n polymorphism in the exonl of the androgen receptor (AR) gene and its relation to the sensitivity of hypoxic training in men of Han nationality from northern China. Methods Sixty five healthy young men of Han nationality completed HiHiLo training under simulated normobaric hypoxic environment for 4 weeks. They stayed under the condition of 14.3-14.8% O_2 (simulating 2800～3000m) during nighttime and carried out hypoxic training under the condition of 14.8-15.4% O_2 (simulating 2500～2800m) 3 times per week at the intensity of 75% individual VO_2max. VO_2max and body weight of the subjects were measured. GeneScan method was used to identify the repeat alleles (genotypes) of CAG polymorphism. Results (1) Fifteen alleles (CAG)12,(CAG)16-28,(CAG)30 repeat alleles (genotypes) were observed in the subjects, in which (CAG)22 was the most common allele; (2) When 21 and 22 alleles were used as the cut point, the baseline of body weight in those carrying shorter genotypes was significantly lower than that in those carrying longer genotypes; (3) △VO_2max and △rVO_2max in men carrying shorter genotypes were significantly higher than that in men carrying longer genotypes after hypoxic training. Conclusion The result reveals that AR (CAG)n polymorphism is associated with the sensitivity of simulated normobaric hypoxic HiHiLo training in men of Han nationality from northern China, especially in those carrying shorter genotypes of AR CAG.
ABSTRACT
Objective To explore the association between VEGF gene polymorphism and the changes in cardiac function after HiHiLo. Methods Sixty two men of Han nationality from northern China underwent HiHiLo for 30 days. Training programme was as follows:exposure in hypoxic environment (14.8% - 14.3%O_2) 10hrs per day, hypoxic training three times per week (15.4%～14.8%O_2), and training at sea level in the remaining time. The genotype was analyzed by PCR-RFLP. Results There is an association between VEGF gene polymorphism and the changes in left ventricular structure and function after 4-week HiHiLo. LVM, LVMI, SV and SI after HiHiLo increased significantly in men carrying CC genotype were better than those carrying CT genotype. Conclusion Men of Han nationality carrying CC genotype probably have a better left ventricular function in response to the HiHiLo than those carrying CT genotype. CC genotype can be used as a genetic marker for the better responsiveness of left ventricular function to the HiHiLo.