Getting back into the gym, I want to maximize my hour at the gym every morning. I havent been active for quit some time, and am starting to lose weight. I find the treadmill hard as my ankles quickly hurt. I always hear running is the best exercise though. I do only about 1 mile on the treadmill, which takes me about 15 min. On the other hand I'm doing 7.5 miles on the stationary bike which takes me about 25 minutes. Should I push myself harder on the treadmill or is the bike equally effective?