I'm a smaller guy. 5'8 and about 150lbs after a meal. I'm turning 19 in 3 weeks. I used to workout with heavy weights religiously and got up to about 160lbs. Thing is though - I sacrificed technique for raw power and ended up hurting my body because of it. It's pretty easy to hurt yourself when you don't have a lot of muscle mass. I stopped lifting weights just about a year and a half ago since I got really nasty tendonitis in both of my arms and experience a lot of on-off pain from the wrists to the shoulders. I notice it a lot when I'm grappling and kickboxing because the joints seem to 'jar' and really the only thing I've learned to do was rest them and keep going until they mess up again. I have a hard time keeping good form with pushups due to wrist pain, so I feel the need to turn my wrists at a 45 degree angle for comfort (I can't see that being good for the elbows though). I also have really bad knees and I feel this would prevent me from doing exercises like squats. My hips tend to pop out sometimes too. I'm in very good cardiovascular shape. I seem to be able to run as hard as I want for as long as I want without experiencing fatigue. I can outlast anyone grappling because of my conditioning and just don't get tired. I really like having this edge and don't want to hinder it because of weight lifting. So I've got some questions: 1. Will weight lifting be counter-productive to my cardio? I'm thinking it probably wouldn't matter so much since I likely wouldn't put on more than 10lbs max with my current frame but don't know too much about it. Also if I'm supposed to be resting, would running work against muscle growth? 2. How much rest time should I give myself inbetween workouts? 3. What supplements are good to take for assisting in joint strength? How pricey are they? Also what kind of supplements would you recommend for me and the daily intake? 4. Can someone give me a few good back strengthening exercises (with a proper number of reps/sets/weight)? I think this is my number one problem area. I always have a stiff and sore back and feel strengthening it would fix the problem. Anyway, thanks to whomever can help me with this. I don't want to be big, I don't care about achieving a high bench press (I hit 240 when I was weight lifting and attirbute my fucked up wrists to that - so I'm staying away from that type of weight lifting), I just want to have a stronger and healthier body.