Muscles running our of gas.

Ruger2506

Can someone explain to me how this works. You are working out and you simply cannot do any more reps. There is just nothing left in the muscles. However you rest for about 5 minutes and you can bust out another set of reps. What happens there? What do you run out of and gets replenished so rapidly?

Toddrific

Science!
http://youtu.be/00jbG_cfGuQ