http://www.bbc.com/news/health-43347409 Researchers say they may have worked out why there is a natural loss of muscle in the legs as people age - and that it is due to a loss of nerves. In tests on 168 men, they found that nerves controlling the legs decreased by around 30% by the age of 75. This made muscles waste away, but in older fitter athletes there was a better chance of them being 'rescued' by nerves re-connecting. The scientists published their research in the Journal of Physiology. As people get older, their leg muscles become smaller and weaker, leading to problems with everyday movements such as walking up stairs or getting out of a chair. It is something that affects everyone eventually, but why it happens is not fully understood. Muscle loss: The femur bone is in the middle creating a black ring, muscles are shaded grey and fat is white. Prof Jamie McPhee, from Manchester Metropolitan University, said young adults usually had 60-70,000 nerves controlling movement in the legs from the lumbar spine. But his research showed this changed significantly in old age. "There was a dramatic loss of nerves controlling the muscles - a 30-60% loss - which means they waste away," he said. "The muscles need to receive a proper signal from the nervous system to tell them to contract, so we can move around." The research team from Manchester Metropolitan University worked with researchers from the University of Waterloo, Ontario, and the University of Manchester. They looked at muscle tissue in detail using magnetic resonance imaging (MRI) and they recorded the electrical activity passing through the muscle to estimate the numbers and the size of surviving nerves. The good news is that healthy muscles have a form of protection: surviving nerves can send out new branches to rescue muscles and stop them wasting away. This is more likely to happen in fit people with large, healthy muscles, Prof McPhee said. Although it is not known why connections between muscles and nerves break down with age, finding out more about muscle loss could help scientists find ways of reversing the condition in the future.
It's got to be lack of use that causes that. The more you stimulate the muscles through physical stress, the more demand is placed on the nervous system to stay functional.
Although I imagine the arms would be next in line, being extremities, I can't imagine any muscle groups would fare much better in older people who fail to use and challenge them regularly. The effect on legs is just more dramatic because it is most closely linked to mobility.
Doesn't it seem odd that researchers spent money to come to the conclusion that muscles atrophy from lack of use as we get older? Seriously.. lot of wasted money flowing in academia...
Age-related muscle atrophy isn't the news. They were more directly addressing the loss of nerves and nerve signals associated with age-related muscle atrophy. So there is perhaps something of a cascading effect; a downward spiral. This makes the need to stay fit and active all the more compelling, to slow down the process.
This book came out in 1992. Discusses the 10 biomarkers of aging and how engaging in resistance exercise can reverse many of these biofactors and is backed up by research. Indirectly touches on this.
Jump ropes and roller blades are great affordable tools to add to an exercise kit. Of course one does have to actually use them.
This thread reminds me of this study: According to my study, you are losing muscle mass at old age due to aging...
Well you lose muscle due to atrophy, not just getting old. Muscle fibers do srhink if they are not stressed on a regular basis over time, no matter your age (i.e. have you seen a teenagers arm after a cast is taken off after 6 weeks?) People who train their muscles while they age still have their muscles so it is not just causation.