I am 18 years old and about 160lbs. I am trying to get in better shape because I have never worked out a lot. A few sit ups here and a few push ups there is about my weekly routine. I have always tried to run but everytime I tried I would have a problem with cramps in my stomach. I would run a few blocks and then a sharp pain would arise on the lower left side of my stomach area. I don't know what to do. My body can keep running but the cramps just won't let me. Please help! What am I doing wrong?