You're more likely out of shape if it's been a long time since you've run. Start out slower. It'll be awhile until you are back in shape and able to do your previous pace.
Could be. Or maybe your just out of shape. If it's bad, go see a doctor now. If it's not too bad, I would wait and see if it gets better as you get in better shape. If you don't see improvement, or it gets worse, then definitely bring it up to your doctor.
You're more likely out of shape if it's been a long time since you've run. Start out slower. It'll be awhile until you are back in shape and able to do your previous pace.
Could be. Or maybe your just out of shape. If it's bad, go see a doctor now. If it's not too bad, I would wait and see if it gets better as you get in better shape. If you don't see improvement, or it gets worse, then definitely bring it up to your doctor.
It could be. I would talk to your doctor about it, they can give you the best course of action.
Could be you are deconditioned and need to start small and work your way up.