Physical activity, genes, and lifetime predisposition to chronic disease

Abstract

Abstract This mini-review summarizes the main associations between physical activity and chronic diseases and discusses the basic concepts related to the role of genetic factors in studies evaluating the effects of physical activity/exercise therapy on chronic disease prevention/treatment during the life course. Many observational cohort studies have shown that high physical activity during young adulthood or middle age is associated with reduced later life morbidity, mobility limitations and mortality. Physical activity or exercise therapy has a positive effect on health via many disease-specific mechanisms. The most consistent finding of the various randomized controlled studies conducted to date is that aerobic/functional capacity and/or muscle strength can be improved by exercise training among patients with different chronic diseases. Genes are known to play a role in chronic disease predisposition and to contribute to physical fitness levels, physical activity participation and ageing. Physical fitness, physical activity and health outcomes may be partly due to underlying genetic factors that have a favourable effect on all these traits (genetic pleiotropy). This means that in observational studies, the relationship between baseline activity and the later occurrence of diseases may not be interpreted entirely as causal. Increased knowledge on the role of nuclear genome, mitochondrial genome, epigenetics, telomeres and regulation of gene expression will increase our understanding of their relationships with physical activity and morbidity.