Michigan Medicine researchers have found that a conserved class of proteins known as Sestrins can mimic many of the beneficial effects of exercise on metabolism in flies and mice, and boost their physical endurance. The team developed a protocol for endurance training and measuring physical endurance in Drosophila, and showed that lack of sestrin prevented flies from building up endurance after exercise training, while overexpression of sestrin boosted endurance, even without exercise. The requirement for sestrin for exercise endurance was mirrored in trained control, and Sestrin-deficient mice.