A treatment which could stop muscles shrivelling up could potentially help the elderly and stroke victims.

It could even prevent people with broken bones having to rebuild their strength from scratch.

However, experts have warned that the technique, which works on laboratory mice, is a long way from being converted to help humans.

Scientists at the University of Florida exposed muscle to 106 degrees farenheit (41°C) for 15 minutes.

They found that the heated mice had far higher levels of heat shock protein (HSP), which has been found to stop muscle breaking down when not used.

The treatment had to be repeated once every week to keep the muscles strong, and the team believes that human testing is not far off.

Professor Scott Powers, who led the team, said: "Muscle atrophy occurs when there is a decrease in the rate of protein synthesis and an increase in the rate of protein in the muscles."

The potential applications of the treatment are vast, including even astronauts whose muscles wither as they are exposed to weightlessness.

Vicious circle

But the elderly could benefit, particularly those caught in what geriatricians call a "vicious circle" of muscle weakness leading to immobility, which leads to yet more muscle wastage and possibly damaging falls.

Exposure to 106 degrees is likely to be uncomfortable but not necessarily painful.

Professor Ray Tallis, an expert in geriatrics from the University of Manchester, described the use of heat as "biologically plausible".

He said: "It's very interesting as a potential new approach to muscle wasting.

"Clearly this needs to be researched more fully - it's a long way from a mice to an older person."

Currently, people with muscle wastage are subjected to long-term physiotherapy to build up the muscles through exercise.

Other innovative techniques, researched by Professor Tallis, include sending electrical signals into the muscle in a pattern that mimics the body's natural instructions to build muscle.

However, this has had only limited success in trials.