Age‐related decline in muscle oxidative capacity reduces muscle function and physical performance, leading to disability and frailty. Whether age‐related decline in oxidative capacity is modified by exercise and other lifestyle practices is unclear. Therefore, we tested the hypothesis that physical activity is associated with better oxidative capacity, independent of age.. To read the full article, log in using your NHS Athens details. To access full-text: click “Log in/Register” (top right hand side). Click ‘Institutional Login’ then select 'OpenAthens Federation', then ‘NHS England’. Enter your Athens details to view the article.