I've been debating whether or not to buy creatine and take it before I workout at my gym. What would it do for me and are there any long term effects of it? Also, I've heard you can gain muscle mass and they will appear bigger, does that mean I need to lift weights or just do exercises using the arms? (Ex. Heavy bag, speed bag, double end bag, punching in the air with weights)
Your balls will shrink and you'll get cancer and die and test positive for steroids. Or you'll be able to bang out a few more reps of whatever it is you're doing. One of those two things.
It can help with repeated sprint efforts or help you get out a couple of extra reps of a heavy weight. Probably a waste of time for a boxer as you'll likely put on a few pounds of water weight while you are on it. If you do take it I'd advise to take small amounts over a month rather than going on a loading phase at the beginning. That way you'll avoid shocking your body and possibly causing health problems. After a month you'll have the same levels as if you've loaded anyway. Also avoid caffeine while you're taking it. If you're not planning on getting out a couple more sprints at 100% or lifting very heavy weights for a couple more reps then you should avoid it really.
Alright, say I use creatine to increase my sprint output, what physical results will I see over a course of time?
It depends on alot of things, particularly your training status and your genetics. When you say physical do you mean your physical appearance? Different effects for different people, generally on creatine your muscles will look fuller while you're on it due to the retention of water.
Personally i think money and time is better spent working out a fairley balanced diet thats not too taxing on body or mind. I can remember quite a few years back reading an interesting write up with good sources about creatine and oxidisation and how eating high G.I carbs with quality proteins has just about the same effect that creatine has.