Tired "core"

I am hitting my peak workouts for IMCDA. Yesterday I rode 110 miles, than ran for 45 min. I noticed during the run that my legs were not the weak link. It was actually my “core” body that was exhausted. Does anyone else feel that way ever?

-TxDude

“Does anyone else feel that way ever”

Felt that way yesterday after a three hour ride at a fairly brisk pace. Came home and laid on the sofa to rest for a couple of minutes. Woke up an hour and half later.