Inactivity reduces people’s muscle strength
Aerobics such as bike training not enough to reverse muscle strength loss. You need weight training
NEWS release from The Center for Healthy Aging and the Department of Biomedical Sciences at the University of Copenhagen who conducted the research.
New research reveals that it only takes two
weeks of not using their legs for young people to lose a third of their
muscular strength, leaving them on par with a person who is 40-50 years their
senior.
Time and again, we are told that we need to stay physically
active and exercise daily. But how quickly do we actually lose our muscular
strength and muscle mass if we go from being averagely active to being highly
inactive? For example when we are injured, fall ill or simply take a very
relaxing holiday. Researchers from the University of Copenhagen have examined
what happens to the muscles in younger and older men after a period of high
inactivity, by way of so-called immobilization with a leg pad.
Both older and younger people lose muscular strength
"Our experiments reveal that inactivity affects the
muscular strength in young and older men equally. Having had one leg
immobilized for two weeks, young people lose up to a third of their muscular
strength, while older people lose approx. one fourth. A young man who is
immobilized for two weeks loses muscular strength in his leg equivalent to
ageing by 40 or 50 years, " says Andreas Vigelsø, PhD at the Center for
Healthy Aging and the Department of Biomedical Sciences at the University of
Copenhagen.
Young people lose twice as much muscle mass
With age, our total muscle mass diminishes, which is why
young men have approx. one kilogram more muscle mass in each leg than older
men. Both groups lose muscle mass when immobilized for two weeks – young men
lose 485 grams on average, while older men lose approx. 250 grams. The
participants’ physical fitness was also reduced while their one leg was
immobilized in a pad.
"The more muscle mass you have, the more you’ll lose.
Which means that if you’re fit and become injured, you’ll most likely lose more
muscle mass than someone who is unfit, over the same period of time. But even
though older people lose less muscle mass and their level of fitness is reduced
slightly less than in young people, the loss of muscle mass is presumably more
critical for older people, because it is likely to have a greater impact on
their general health and quality of life, " Martin Gram, researcher at the
Center for Healthy Aging and the Department of Biomedical Sciences, explains.
Cycling is not enough
After two weeks of immobilization, the participants
bicycle-trained 3-4 times a week for six weeks.
"Unfortunately, bicycle-training is not enough for the
participants to regain their original muscular strength. Cycling is, however,
sufficient to help people regain lost muscle mass and reach their former
fitness level. If you want to regain your muscular strength following a period
of inactivity; you need to include weight training", Andreas Vigelsø
states.
"It’s interesting that inactivity causes such rapid
loss of muscle mass, in fact it’ll take you three times the amount of time you
were inactive to regain the muscle mass that you’ve lost. This may be caused by
the fact that when we’re inactive, it’s 24 hours a day," Martin Gram concludes.
These results have just been published in the scientific
Journal of Rehabilitation Medicine. The Nordea-fonden supports the research
carried out by the Center for Healthy Aging.
