Q: How long does it take for sit ups to start having a strong effect. I do about 150-200 a day? Also, good diets/lifting programs for gaining decent size muscles.

A: Doing sit ups alone will do pretty much nothing for you, no matter how many you do. The only thing you will get is good abdominal strength/endurace. But you will not lose extra weight/fat by doing them and you certainly won't get a six-pack. It's a myth that sit ups will give you good-looking abs -- it won't happen. If you're serious about getting results, whether to gain muscle or lose fat, you need a complete diet + exercise program that works all the muscle groups of your body, not just the abs. You can get just such a program by filling out http://www.mikesfitness.com/content/fitnessguide . You may also want check out other articles on that page. Good luck!