Scientists believe we could be closer to developing a drug that gives us the benefits of exercising without moving a muscle.

A studies has shown that a compound affected levels of a protein called REV-ERB in muscles - which has been shown to boost metabolism, normalize cholesterol levels and affect how much we sleep.

The study, published this week by researchers at the Scripps Research Institute in Florida, found that when their compound was injected into obese mice, it helped them lose weight - even if they were on a high-fat diet - and improved their cholesterol levels, according to a New York Times report.

The treated mice also began using more oxygen throughout the day and expending about 5 per cent more energy than untreated mice, even though they were not moving about more than the other animals.

This in effect means the compound boosted their metabolism.

Scripps scientists also worked with researchers at the Pasteur Institute in France and other institutions, to discover what their compound might be doing inside muscles to provide this 'invisible' exercise.

They knew that their drug increased the potency of the REV-ERB protein, but no one knew what it actually did to muscles.

They therefore developed a strain of mice that could not express very much of the protein in their muscle cells.

These animals were what they described as 'anti-athletes'.

One of the hallmarks of regular aerobic exercise is that it increases the number and activity of the mitochondria, the cellular structures that help to generate energy while consuming oxygen, in the muscles.

But these animals’ muscles contained very few mitochondria.

As a result, the animals had diminished endurance, with a maximam oxygen capacity about 60 percent lower than normal.

They reached exhaustion on treadmill testing long before their unaffected labmates.

But when, in a separate part of the experiment, scientists added their compound to isolated muscle cells from the deficient mice, the cells began pumping out far more REV-ERB.

Those cells, subsequently, began creating large numbers of new mitochondria and strengthening the existing ones.

The drug act as an exercise mimic, explained co-author Thomas Burris, now the chairman of the department of pharmacological and physiological science at St Louis University School of Medicine.

It is not inconceivable, he added, that at some point in the future, such a drug might allow people, especially those who are disabled or can’t otherwise exercise, to enjoy the health benefits of endurance without the exertion.