The Effect of Angiotensin Converting Enzyme Genotype on Aerobic Capacity Following High Intensity Interval Training

International Journal of Exercise Science 7(3) : 250-259, 2014. Obesity increases the risk of developing type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Physical activity can reduce T2DM and CVD risk, and increase aerobic capacity, a significant predictor of all-cause mortality and morbidity. High intensity interval training (HIIT) produces similar improvements in aerobic capacity to continuous moderate exercise (CME). Different genotypes of angiotensin converting enzyme (ACE) have been implicated in improving aerobic capacity and therefore predicted health. This study investigated the effects of different ACE genotypes on the impact of 6 weeks of HIIT on aerobic capacity, and thus health status. 20 young adults were recruited for this study; test subjects completed 6 weeks of HIIT 3 times a week. VO2max was tested to determine aerobic capacity pre- and post-HIIT and DNA collected from saliva for determination ACE genotype. After 6 weeks of HIIT there was no significant change in VO2max; when subjects were separated into responder categories, high responders significantly increased their aerobic capacity whilst there was a large but non-significant decrease in non-responders. Subjects carrying a D-allele showed a significant increase in VO2max following HIIT indicating specific ACE genotypes may be associated with differing VO2max responses. These preliminary results suggest that HIIT can significantly reduce the time required for exercise whilst still achieving notable improvements in aerobic capacity in high responders; they also indicate that ACE D-allele carriers who would not usually be expected to show large VO2max responses following CME may yield equivalent aerobic capacity improvements following HIIT, and thereby reduce their overall morbidity and mortality disease risk