The data do not indicate that we experience the same need to work at max energy for brief periods of time as hunter/gatheres. Besides running away from predator

The data do not indicate that we experience the same need to work at max energy for brief periods of time as hunter/gatheres. Besides running away from predators in most efficient way, consider throwing оf javelins or stones during hunting. It requires a very precise muscle work at max energy after intense brain activity of target selection. Modern day life does not involve that, yet evolutionary this combination of brain/muscle work at peak could be advantageous.