1 Enter AICAR, which targets a protein called adenosine monophosphate - activated protein kinase ( AMPK ).

2 So, by using AICAR, the scientists thought they might be able to trick the body into thinking it was exercising.

3 When given daily doses of AICAR, but no exercise training, another set of mice could run 23% longer and 44% farther than untreated mice.

4 AICAR, for instance, activates an enzyme that prompts the body to burn fats and sugars when energy levels are low.

5 The scientists examined the effects of two compounds, called GW 1516 and AICAR , on endurance in mice.

6 In a further experiment, the investigators fed untrained mice a substance called AICAR, a synthetic version of AMP that triggers the AMPK switch directly.