Genetics of Regular Exercise and Sedentary Behaviors

Abstract

Studies on the determinants of physical activity have traditionally focused on social factors and environmental barriers, but recent research has shown the additional importance of biological factors, including genetic variation. Here we review the major tenets of this research to arrive at three major conclusions: First, individual differences in physical activity traits are significantly influenced by genetic factors, but genetic contribution varies strongly over age, with heritability of leisure time exercise behavior ranging from 27% to 84% and heritability of sedentary behaviors ranging from 9% to 48%. Second, candidate gene approaches based on animal or human QTLs or on biological relevance (e.g., dopaminergic or cannabinoid activity in the brain, or exercise performance influencing muscle physiology) have not yet yielded the necessary evidence to specify the genetic mechanisms underlying the heritability of physical activity traits. Third, there is significant genetic modulation of the beneficial effects of daily physical activity patterns on strength and endurance improvements and on health-related parameters like body mass index. Further increases in our understanding of the genetic determinants of sedentary and exercise behaviors as well as the genetic modulation of their effects on fitness and health will be key to meaningful future intervention on these behaviors.

Effects of intrinsic aerobic capacity, aging and voluntary running on skeletal muscle sirtuins and heat shock proteins

“…Taken together, our results are consistent with previous data on rodents 15,25,26 and humans 27,28 , which indicated that genetic predisposition plays a significant role in exercise participation. These results are also consistent with our previous suggestion 14 that genetic pleiotropy may partly explain the associations observed between high physical activity and mortality in our past epidemiological studies, which called for high quality intervention studies to analyse the true effects of physical activity on morbidity and mortality among initially healthy individuals.…”

“…Our results indicate that genetic predisposition plays a significant role in exercise participation, which is consistent with previous data in rodents Kelly et al 2010;) and humans de Geus et al 2014). These results are also consistent with previous suggestion that genetic pleiotropy may partly explain the associations observed between high physical activity and mortality .…”

“…We hypothesized, that LCRs might have higher maximal twitch force (N) compared to HCRs due to bigger muscle size and larger relative amount of 2b muscle fibers with better force-generating capacity compared to 2a fibers of HCRs [19,27,28]. No significant difference, however, was observed in maximal twitch force between the groups in the beginning of the stimulation protocol.…”

“…We also hypothesize, that compared to HCRs, the twitch parameters of LCRs are more typical of fast twitch muscles due to larger relative amount of type 2b muscle fibers [19,27,28].…”

Heritability of heart rate recovery and vagal rebound after exercise

“…Because regular exercise behavior has been shown to be a heritable trait (de Geus et al 2014) it could be an important mediator of genetic effects on HRR and vagal rebound. Such hypotheses can be tested in twin models using a multivariate extension of the MZ and DZ twin (co)variance analysis.…”