Not everyone can exercise. People with muscle-wasting diseases and movement disorders, the frail, the very obese and post-surgical patients are among those who face a significant challenge when it comes to working out.

This can be frustrating, considering the well-established benefits of exercise.

But what if a drug could stimulate the body into producing some of the same effects of exercise - more endurance and weight control, for example - without the need to run a single step?

Such a pill may be on the way. Several scientists are testing compounds that apparently can do this - and people wouldn't even have to move at all to benefit.