Some stretches of DNA are littered with methyl groups-chemical tags that, without changing the DNA sequence, prevent expression of nearby genes. These epigenetic modifications are often inherited and fairly permanent. But not always: Exercise, it turns out, leads to immediate, reversible changes to DNA methylation in muscle cells. In a new study, 14 sedentary young men and women exercised to fatigue on a stationary bike. Researchers collected thigh-muscle biopsies before and 20 minutes after the session.
展开▼
