Dark red marks on foot arch, is it okay?

Well I've been working out alot, on my feet alot, and today I did a little over 3 hours of rebounding (mini trampoline) and when I stopped to take a break after the 3 hours I noticed there were long red marks all along the arch of my foot. I'm wondering if that's bad or if it just means it's irritated. If it's just irritated that's okay I just want to make sure I'm not really damaging my feet or anything. Because I need to do 2 more hours and I usually do 1 hour of jump rope as well and 2 workout DVD routines and some dancing so I just want to make sure my feet are okay and it's not a sign of an injury to come or anything. Also all the workouts I do are with bare feet, I refuse to workout with shoes on unless I'm dancing because they completely throw me off. Oh and don't ask why I'm working out so much lol there is a good reason. Thanks!