Precision Physical Therapy: Exercise, the Epigenome, and the Heritability of Environmentally Modified Traits

Abstract

One of the newest frontiers of physical therapy is the field of epigenetics, which examines how pervasive environmental factors such as exercise regulate the expression of genes. The epigenome may be one of the most powerful systems through which exercise exerts its beneficial effects on health and longevity. Large epidemiology studies show that individuals who regularly exercise demonstrate a lower "epigenetic age," experience fewer metabolic diseases, and enjoy greater longevity. However, the dose, mode, intensity, and duration of exercise required to achieve a healthy epigenetic profile is unknown. As experts in exercise prescription, physical therapists are ideally suited to contribute to the discovery of this dose-response relationship. This perspective makes a case for the genesis of "precision physical therapy," which capitalizes on epigenetic discoveries to optimize exercise-based interventions. Summarized here is the emerging body of knowledge supporting epigenetic adaptations to exercise in humans, including the intriguing possibility that these environmentally modified traits could be passed down to offspring. In the future, it is likely that epigenetic data will enhance our understanding of individual disease risk and individual response to prescribed exercise. The profession of physical therapy must be alert to new epigenetic knowledge that can enhance the specificity and efficacy of movement-based treatments.

Figures

Figure 1.

Simplified illustration of the steps involved in transcription and translation. Arg, Val, and Pro are arginine, valine, and proline amino acids, respectively.

Figure 2.

Histone acetylation. Histone acetyl transferase (HAT) transfers an acetyl group from acetyl-CoA to histone tails. Acetylation relaxes the DNA-histone arrangement, which makes the DNA accessible for transcription, increasing gene expression.

Figure 3.

PubMed search results regarding exercise and epigenetics. Through 2016, over 400,000 articles with “exercise” or “physical activity” as a keyword had been published. Articles with “epigenetic” or “epigenetics” as a keyword totaled ∼60,000. Fewer than 600 articles include both sets of keywords (inset panel).