ABSTRACT
Objective To explore the relationship between the angiotensin-converting enzyme(ACE) gene inserton/deletion(I/D) polymorphism and the cardiorespiratory fitness. Methods One hundred twenty six male subjects were recruited and randomized into a physical exercise(n=65) or a control group(n=61).The men in the physical exercise group were trained with mild-moderate intensity physical exercise for 5 years. The men in the control group were advised to make their personal choice whether or not to engage in physical exercise. The cardiorespiratory fitness indices,e.g. aerobic threshold were measured at baseline and annually. The I/D polymorphism in the 16 th intron of ACE gene was analysed by polymerase chain reaction. Results At baseline, the aerobic threshold was (14.4 ? 3.9)ml?min -1?kg -1 in the physical exercise group. After 5-year physical exercise, the aerobic threshold was (16.4 ? 4.1)ml?min -1?kg -1in the physical exercise group. At baseline, the aerobic thresholds was(14.2 ?3.6)ml?min -1?kg -1in the control group. After 5 years, the aerobic threshold was(13.8 ? 3.3)ml?min -1?kg -1in the control group. After 5 year physical exercise, compared with the baseline and the control group, the aerobic threshold increased significantly in the physical exercise group(both,P0.05). Conclusions Regular low to moderate intensity physical exercise can increase aerobic threshold and improve cardiorespiratory fitness. Compared with the subjects with the ACE DD genotypes, the cardiorespiratory fitness can be improved more easily for the subjects with the ACE II,ID genotypes.