Couch potatoes are missing exercise gene

Couch potatoes may have a valid excuse for not having any get-up-and-go - they are missing the exercise gene.

While people may think they are lazy, in reality there may be fundamental flaws in their genetic make-up.

Researchers working on mice on mice removed two genes in muscle essential for exercise and then found they could not do as much as their healthy counterparts.

The genes control the protein AMP-activated protein kinase (AMPK), an enzyme that is switched on when you exercise.

Associate professor of medicine Gregory Steinberg said: ""Mice love to run. While the normal mice could run for miles, those without the genes in their muscle could only run the same distance as down the hall and back.

"It was remarkable. The mice looked identical to their brothers or sisters but within seconds we knew which ones had the genes and which one didn't."

The researchers found the mice without the muscle AMPK genes had lower levels of mitochondria and an impaired ability for their muscles to take up glucose while they exercise.

He said: "When you exercise you get more mitochondria growing in your muscle. If you don't exercise, the number of mitochondria goes down.

"By removing these genes we identified the key regulator of the mitochondria is the enzyme AMPK," said Prof Steinberg.

He added the findings are important for individuals who find it difficult to exercise, such as the obese, asthmatics and people in wheelchairs.

Their inability to exercise may lead to other complications such as diabetes and heart disease.

And he warned: "As we remove activity from our lives due to emerging technology, the base level of fitness in the population is going down and that is reducing the mitochondria in people's muscles.

"This in turn makes it so much harder for people to start exercising."

Steinberg himself runs or bikes to work, saying: "It is the only way that I can manage to make sure I stay fit."

The study by the team from McMaster University in Canada appears in the current issue of the Proceedings of the National Academy of Sciences.


/The Telegraph/