With An Injection, Mice Nearly Double Their Endurance

It's a familiar scene that played out most recently at the London marathon: An exhausted runner staggers and falls in the home stretch, unable to will their legs forward another step. It's an extreme example of a phenomenon endurance athletes come to know intimately, often called "hitting the wall," or sometimes by the more offbeat term "bonking." The proverbial wall appears when our bodies have run out of stores of glucose, a sugar molecule that is our main source of energy during strenu