"Tough As Nails": Chest Pain....A result of overtraining?

I don't think this is the right category to post my discussion but I really need some input on this so I posted on the first category.

I am a touring musician and while im on tour I have alot of time, so every morning I run for at least 4 miles, and do some light aerobics, and tension cable workouts when I get back. I love running, and I especially love it on tour because its my time to get away from all the people and the noise, and just listen to my ipod and explore.

Yesterday I did my usual run and workout as I usually do in the morning. We played our normal 30 minute set and I returned to the bus to relax. I then realized I had to run to the bank to make a deposit. The bank was about 2 miles away, and I only had 15 minutes to get there before it closed so I got my friends bike and rode like a bat out of hell to get there. On the way there I started to get a chest pain or cramp in  the left side of my chest. I never made it to the bank in time, and the pain in my chest hasn't gone away yet. Can anyone explain what the cause of this chest pain is? Our 30 minute set is also tough sometimes too. The temperature has been averaging about 90 degrees at every city we've played, and I we all run around quite a bit during it, sweating perfusely.

I skipped my run today, and I'm going to take it easy and see if it goes away tomorrow. Any input would be greatly appreciated.

Thank you in advance,

Matt

Phoenixville, PA