50-year-old muscles just can’t grow big like they used to – the biology of how muscles change with age
- Written by Roger Fielding, Associate Director of the Jean Mayer USDA Human Nutrition Research Center on Aging, Professor of Medicine, Tufts University

There is perhaps no better way to see the absolute pinnacle of human athletic abilities than by watching the Olympics. But at the Winter Games this year – and at almost all professional sporting events – you rarely see a competitor over 40 years old and almost...