Pill that could get you fit without leaving the sofa

IT’S the scientific breakthrough couch potatoes have been waiting for – the benefits of an arduous workout without even needing to break a sweat.

And ‘exercise in a pill’ could be a step closer, with a drug that mimics the effect of training for long-distance running.

It may have the potential to help those unable to exercise because of conditions such as diabetes or heart problems.

The drug, which has so far been tested only in mice, mimics the way that runners’ muscles shift from burning carbohydrates, or sugar, to burning fat.

Professor Ronald Evans, senior author of the study from Salk Institute in California, said: ‘It’s well-known that people can improve their aerobic endurance through training. The question for us was, how does endurance work? And if we really understand the science, can we replace training with a drug?’

The study, published in the journal Cell Metabolism, found a gene which, when activated, made mice resistant to weight gain and highly responsive to insulin – the same qualities seen in very fit people.

Then they found a drug which activated the gene in normal mice after eight weeks and boosted the animals’ stamina. Mice that had been given the drug could run on a treadmill for 70 per cent longer before they were exhausted, even though they still had a sedentary lifestyle.

Weiwei Fan, the study’s first author, said: ‘It means you can improve endurance to the equivalent level as someone in training, without all of the physical effort.’

A drug which burns fat instead could be used in elderly, obese or otherwise mobilitylimited people, who are unable to exercise.