Good old Army PT keeps me in pretty decent shape. The nice thing about it is that is does not require a gym and it's totally free. Lots of exercises: pushups, situps, pullups, rowers, V-ups, burpees, mountain climbers, and too many more to mention here. You can look it up Army PRT on the Internet and get an idea. I also like to run a good bit, but I tend to gravitate more towards sprinting than distance running. Bear in mind that none of these exercises will help you get ripped muscles, but they will keep you conditioned pretty well. I also don't drink soda, avoid fast food whenever possible. Oh and drink a lot of water, its so good for you.