Originally posted by Cogitowell in Rebirth Barry was running nonstop for a relatively unknown amount of time (not sure how much joining the speedforce and relativity affects him in terms of how long he perceived he was there) and he was still going strong and he said he would have basically been running forever so yes I assume so if he was running at top speed doing the same thing Barry would have infinite endurance.
Doesn't the speedforce provide infinite endurance?