London: Working out can help you look and feel younger - or at least that`s what most of us who regularly work out fondly hope. Now scientists have discovered why exercise can hold back the years.
A study found an endurance exercise like a jog or spinning class increases the number of stem cells in our muscles, helping rejuvenate them, reports the journal PLoS ONE.
Tests showed that rats running on a treadmill for just 20 minutes a day could increase stem cells by almost half, proving exercise could be the secret of youth for our muscles, according to a newspaper report.
Professor Dafna Benayahu from the Tel Aviv University`s Sackler School of Medicine in Israel, who ran the study, said: "When we age, we experience sarcopenia, a decline in mass and function of muscles."
"As a result, our musculoskeletal system is more susceptible to daily wear and tear, which also explains the increased risk of falling in the elderly."
"For the first time our findings can explain why older people who have exercised throughout their lives age more gracefully."
The number of muscle stem cells normally declines with ageing. This prevents proper maintenance of muscle mass and its ability to repair itself. However, tests on rats who ran for 20 minutes a day for 13 weeks found the opposite happened.
The results showed younger rats exhibited a 20 to 35 percent increase in the average number of stem cells per muscle fibre. Older rats benefited even more, showing a 33 to 47 percent increase.