Winding Down

Not only do we change on the outside as we get older, such as grey hairs and wrinkles, there are changes on the inside that affect physical fitness and walking speed. However, these changes don’t progress at the same pace for everyone, and it’s not entirely clear what underlying biological changes are responsible for the decline. Studying ageing in humans obviously takes a very long time, so researchers have been using mice as a shortcut. By comparing the molecular makeup and metabolism of leg muscles from animals at different ages – 7 months (left) 13 months (centre) and 21 months (right) – they've shown that it takes more energy to do the same amount of physical activity in older mice compared with younger ones. No-one can live forever, but knowing more about what happens as we get age could lead to new ways to keep us healthy and active for longer.

Written by Kat Arney

Kat Arney

Writer

Dr Kat Arney is an award-winning science writer, broadcaster and public speaker, and is the founder and Creative Director of First Create The Media.

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• Image from work by Michael A Petr and colleagues
• Translational Gerontology Branch, National Institute on Aging, NIH, Baltimore, MD, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in eLife, April 2021