No exercise was created equal. You might like running, so run. You might like jogging, so jog. You might like stationary bikes, so bike stationarily. Find the one that works best for you - that isnt too much of a chore for you to do regularly throughout the week. Dont pick a routine that you dont like - or you wont want to do it, and you certainly wont stick with it for long. I also wouldnt recommend buying into that whole no pain, no gain mantra. Ive lost weight without hurting myself, and you probably can, too.