Parents run ragged by their children may have suspected it all along.

Youngsters have greater energy levels than professional endurance athletes, scientists have discovered, meaning it is virtually impossible for the average adult to keep up.

And for mothers and fathers hoping that tiring out their little ones will ensure a good night’s sleep, be warned.

Children also have a impressive recovery time, and will be back to their hyperactive best quicker than parents can say ‘lie in.’

“We found the children used more of their aerobic metabolism and were therefore less tired during the high-intensity physical activities," said Sebastien Ratel, Associate Professor in Exercise Physiology who completed this study at the Université Clermont Auvergne, France.

“They also recovered very quickly - even faster than the well-trained adult endurance athletes - as demonstrated by their faster heart-rate recovery and ability to remove blood lactate.

“This may explain why children seem to have the ability to play and play and play, long after adults have become tired.”