Physical inactivity is an important and growing major health concern and is defined as not engaging in any regular pattern of physical activity beyond that associated with daily functioning.1 The many consequences of inactivity include reductions in insulin sensitivity of skeletal muscle and expansion of fat storage, factors associated with the development of obesity, metabolic syndrome and type 2 diabetes.2 Exercise is often performed with the goal of counteracting these changes and enhancing health and life expectancy. Imagine if the health benefits of exercise could be produced simply by taking a so-called “exercise pill”. This would be every couch potato’s dream and may be a reality if a paper recently published in the prestigious journal Cell is any indication.

DISCOVERING THE “MAGIC BULLET”?

Narkar et al3 investigated the benefits of two orally active compounds on exercise endurance in mice. The first compound, known simply as GW1516, did not enhance endurance when given to sedentary mice, but when combined with a progressive treadmill exercise programme, it enabled mice to run 60–75% further and longer than mice exposed to the exercise programme alone. Thus, there was synergy between exercise and GW1516, …