I didn't know our body will react differently to different sports.. that's a new one for me. I thought once you're fit enough in any one etreme sports (like marathon), you'll be fit in most sports (because you already have the stamina needed). Perhaps, in your case, it's because you haven't done any heavy sports for quite a long period, therefore, when you suddenly start one, your body will tend to reject it, no?
I mean, that's what happened in my case. I stopped exercising for almost 2 years. Sleep, eat, go to work, watch TV, no exercise, not even a squat here or a jog there, nada, zilch. Then suddenly go for hardcore exercise, of course the muscles will be in a riot.

) But i read that pain AFTER excercises means it's a good sign for the body. It means it works. If you feel the pain, that means the whole muscles of the body are active and once you're healed, you can go back safely to the gym. You should see this girl who was exercising behind me that day. She was doing pumping! Man, i feel like a twat! I so envied her! #-o#-o