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Updated: Jun 14, 2026
Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice
Published on: March 15, 2019
Association of androgen receptor CAG repeat polymorphism with VO₂max response to hypoxic training in North China Han
Insights
Androgen receptor (AR) CAG repeat polymorphism influences VO₂max response to hypoxic training in North China Han men. Shorter AR CAG genotypes are linked to enhanced exercise performance and better adaptation to simulated high-altitude training.
Area of Science:
- Exercise Physiology
- Human Genetics
- Sports Science
Background:
- The androgen receptor (AR) gene plays a crucial role in male reproductive and developmental functions.
- CAG repeat polymorphism in exon 1 of the AR gene is known to influence AR activity.
- Understanding genetic factors influencing physiological responses to training is vital for personalized exercise prescriptions.
Purpose of the Study:
- To examine the distribution of AR CAG repeat polymorphism in North China Han men.
- To investigate the association between AR CAG repeat polymorphism and cardiorespiratory fitness (VO₂max) response to hypoxic training.
- To determine if genetic variations predict individual adaptation to simulated high-altitude training.
Main Methods:
- Sixty-five healthy young men underwent a 30-day HiHiLo training protocol in a simulated normobaric hypoxic environment.
- VO₂max (peak oxygen consumption) and body weight were measured pre- and post-intervention.
- AR CAG repeat polymorphism was analyzed using genetic genotyping.
Main Results:
- Fifteen CAG repeat alleles were identified, with (CAG)22 being the most prevalent.
- Subjects with shorter AR CAG repeat genotypes exhibited significantly lower baseline body weight.
- Shorter AR CAG genotypes demonstrated significantly greater improvements in VO₂max and relative VO₂max (rVO₂max) following hypoxic training compared to longer genotypes.
Conclusions:
- AR CAG repeat polymorphism is significantly associated with exercise performance adaptations to simulated normobaric hypoxic training.
- Individuals with shorter AR CAG repeat genotypes show a superior individual response to hypoxic training.
- These findings suggest potential genetic markers for predicting training response in hypoxic conditions.
Abstract:
The purposes of this study were to investigate the distribution characteristics of CAG repeat polymorphism in exon 1 of androgen receptor gene and the association of CAG polymorphism with VO₂max response to hypoxic training in North China Han men. Sixty-five healthy young men completed a 30-day HiHiLo training (living high, exercise high and training low) in a simulated normobaric hypoxic environment. All subjects slept in 14.3-14.8% O₂ concentration, and participated in hypoxic training three times a week in 15.4% O₂ concentration. VO₂max (peak oxygen consumption) and body weight were measured before and after hypoxic training. A total of 15 repeat alleles were observed by CAG genotype analyze, in which (CAG)22 was most common. When using 21 and 22 alleles, respectively, as cut-off points, we found that the baseline body weight of two shorter genotype groups was significantly lower than that of longer ones, and that the ΔVO₂max and ΔrVO₂max (Δrelative value of VO₂max) of two shorter genotype groups were significantly higher than those of longer ones after hypoxic training. These findings indicated that AR CAG repeat polymorphism was associated with the exercise performance after simulated normobaric hypoxic HiHiLo training in North China Han men, and that the shorter genotypes had a better individual response to hypoxic training.
