When training for a marathon, how come you only train for up to 20 miles...why not the full?

Question

wouldnt you get tired with the additional 6 miles youve never trained for?

Answer 1

I have known anyone to train for 20 miles. You just get yourself to a state of fitness where you can keep running at a certain speed constantly whilst fueling your body until the end.

Answer 2

Some people do train the full 26.2.  Some even train over distance.  Do what works for you.

Answer 3

Because when you are in training you are running several days a week and your body is going to already be a little broke down and running the extra distance is really only going to put you at risk for injury. The day of the race you should be fresh and rested which will put you at low risk for injury.

Answer 4

If you can run 20 miles, you've reached aerobic fitnes peak. Meaning, running any longer won't help. The adde miles are not ran because of the peaks and limits of fitnes.