Toronto: The "secret" to staying strong as we age is superb fitness that can be achieved by regular exercise, suggests new research.
The study found that people who were elite athletes in their youth or later in life have much healthier muscles at the cellular level compared to those of non-athletes.
The study, published in the Journal of Applied Physiology, compared world-class track and field athletes in their 80s with people of the same age who are living independently.
"One of the most unique and novel aspects of this study is the exceptional participants," said researcher Geoff Power, professor at University of Guelph in Ontario, Canada.
"These are individuals in their 80s and 90s who actively compete in world masters track and field championships. We have seven world champions. These individuals are the creme de la creme of ageing," Power noted.
The study found that athletes' legs were 25 percent stronger on average and had about 14 percent more total muscle mass.
In addition, the athletes had nearly one-third more motor units in their leg muscles than non-athletes.
More motor units, consisting of nerve and muscle fibres, mean more muscle mass and subsequently greater strength.
With normal ageing, the nervous system lose motor neurons, leading to a loss of motor units, reduced muscle mass, less strength, speed and power. That process speeds up substantially past age 60.
"Therefore, identifying opportunities to intervene and delay the loss of motor units in old age is of critical importance," Power said.