I feel honestly 90% of hereos could run marathons. Captain america, tchalla, black widow, cyclops, etc etc etc. Marathons aren't that difficult and most hereos are far above average in physical ability and in stamina.
For example, she hulk can exert herself at peak for 48 hours. But heroes like Silverclaw, who is a demigoddess, White fox, a Kumiho almost never gets tired. At least that's written on their page