Whether working out in the gym or going for a run on the trail, according to Discovery’s article “Biosensor Tattoo Stops Athletes From Crashing,”by Nic Halverson, a temporary tattoo designed by a team of researchers, lets athletes know when they are about to reach their body’s threshold, and to ease up on their work-out routine.

“During exercise, when muscles require more energy than the body can offer from aerobic respiration, the body begins producing lactic acid and lactate,” Halverson wrote. “This suffices for a while, but eventually lactate builds up.”

Find out more about the biosensor tattoo at Discovery.