How many 5 year-olds.....

[Dan BRIGHT]

You have no idea how strong and tough some people that go to gyms really are. On top of that, the ones that do martial arts are even tougher.

The whole thing in the scenario is that if everything is done properly by the lone hero, he would take out a single 5 year old in one strike. Also, each blow from a 5 year old would not do significant damage to him. This is especially true if he is of tall stature.