I enjoy weight lifting as well as a boxing workout. I have access to a heavy bag,a speed bag and a weight machine with pulleys. I know that punching the heavy bag does not provide the strentgh gains that I can get from weight training, but there is some strentgh benefit.

My question is this - If I did a traditional boxer's workout 2-3 times a week (3 rounds heavy bag, 3 rounds shadow box, 3 rounds speed bag, 3 rounds jump rope) - what strentgh exercises could I leave out of an overall weightlifters workout. My goal is to have a cross training program that keeps me in good shape - I'm not training for any competition.

What muscles in the upper body does a left jab, right cross, upper cut and hook develop?

Interesting questions. Did you see the Boxing program? If you have and you feel it is too long you could minimize your chest, shoulders, tricep and calf work somewhat as they will get quite a workout from the 3 rounds each of the heavy bag, speed bag, jump rope, and shodow boxing. Just reduce the number of sets for each of these muscle groups. Taking off 2 sets for each muscle group will do the trick.

Finally, I would say that the left jab, right cross, upper cut and hook combo would work just about everything from your deltoids to your external obliques! I don't believe anything would be left out.