Have you ever wondered why children always seem to have bags of energy and never run out of steam? Researchers have discovered that children have the stamina and levels of recovery of endurance athletes. In fact, scientists say children's muscles recover from "high-intensity exercise" a lot quicker than athletes. A study looked at the performance levels of children when they were cycling, and compared their fitness to that of athletes. Researcher Dr Sebastien Ratel said: "We found the children used more of their aerobic metabolism and were therefore less tired during the high-intensity physical activities. They also recovered very quickly - even faster than the well-trained adult endurance athletes."