RESEARCHERS have discovered why children can run around all day without sweating.
An International Study Published Today Frontiers in Physiology have shown that young children are built as elite marathon runners – or at least their muscles.
Children ages 8 to 12 were found to have muscles that could withstand fatigue, like elite stamina runners, and could come faster from high intensity exercise than untrained adults.
Professor Tony Blazevich, from WA's Edith Cowan University's School of Medical and Health Science, said the children have a lot of aerobic fitness.
"Most of us probably remember that children run outside of hours and hours and then wake up the next day and do it again, but if we tried to do the same as adults, we would be completely broken," he said. .
Queensland-based My First Gym – designed specifically for children aged seven months to 13 years – has found its small members to do the equivalent of 8000 steps each day without stopping.  Director Dan Newton said the challenge was actually to make the kids stop training, rather than start because they were motivated by their "My Movement Buddy" activity tracking.
"We have found it, especially when the activity motivates and exciting, the challenge is not to make them physically active, that is to make them stop.
" They run around an intense Ninja Warrior course until they are red in the face but did not stop before they beat their score from yesterday, beat their classmates or – even better – beat their coach. "