“Exercise-in-a-pill” boosts athletic endurance by 70 percent

Every week, there seems to be another story about the health benefits of running. That’s great—but what if you can’t run? For the elderly, obese or otherwise mobility-limited, the rewards of aerobic exercise have long been out of reach. Co–senior authors Ronald Evans and Michael Downes, together with first author Weiwei Fan and colleagues, have built on earlier work by the lab that identified a gene pathway (PPARD) triggered by running. In the current study, which appeared in Cell Metabolism on May 2, 2017, the team reported fully activating that pathway in sedentary mice with a chemical compound, mimicking the beneficial effects of exercise. They also found that PPARD encourages fat-burning but suppresses sugar-burning in muscles during exercise, likely to preserve sugar for use by the brain. The work reveals why runners who “hit the wall” experience both physical and mental exhaustion upon using up their ready supply of glucose.