Originally Posted by
rpeterson
I've done both, and am an avid triathlete. The marathon is way harder simply because it beats the Hell out of your body. I can do 2 or 3 centuries a week no problem, even a hard road race ever couple weeks, but 2 or 3 marathons a year is all my body can physically handle. It takes way more time to recover from the training and racing.
I think this is the answer everyone should read.
That ability to repeat marathons/centuries each week is the key.