Want to stay young? Lifelong physical activity could protect against age-related loss of muscle mass and function, according to research.

The study, published in The Journal of Physiology, showed that individuals aged 68 and above who were physically active throughout their life have a healthier ageing muscle that has superior functionality and is more resistant to fatigue compared to inactive individuals, both young and old. This is the first study to investigate muscle, stem cell and nerve activity in humans, said researchers from the University of Copenhagen.

"This is the first study in humans to find that lifelong exercise at a recreational level could delay some detrimental effects of ageing. Using muscle tissue biopsies, we've found positive effects of exercise on the general ageing population. This has been missing from the literature as previous studies have mostly focused on master athletes, which is a minority group," said lead author Casper Soendenbroe, from the varsity.

They found that elderly individuals who keep physically active throughout their adult life, whether by taking part in resistance exercise, ball games, racket sports, swimming, cycling, running and/or rowing had a greater number of muscle stem cells, otherwise known as satellite cells in their muscle. These cells are important for muscle regeneration and long-term growth and protect against nerve decay.

In the study, 46 male participants took part and were divided into three groups: young sedentary (15), elderly lifelong exercise (16) and elderly sedentary (15). They performed a heavy resistance exercise, sitting in a mechanical chair performing a knee extension movement to evaluate muscle function. The amount of force produced was measured. Blood samples were taken, and muscle biopsies were analysed from both legs.

The researchers found elderly lifelong exercisers outperformed both the elderly and young sedentary adults. Importantly, the study showed that even a little exercise seems to go a long way when it comes to protecting against the age-related decline in muscle function.

"This is an encouraging finding which can hopefully spur more people to engage in an activity that they enjoy. We still have much to learn about the mechanisms and interactions between nerves and muscles and how these change as we age. Our research takes us one step closer," Soendenbroe said.