If you're primary goal with your workouts is to build muscle, everything you do in the gym needs to be directed towards achieving this goal. If you aren't optimizing all the different types of activities towards your ability to build muscle, your results are going to fall short of where they could be. Be it is going to take the body a great deal of energy to build muscle, after completing your intense weight lifting workout sessions, you don't want to be placing too much additional stress on the body, or else you could jeopardize your recovery, which then translates to a smaller weight gain for you. One mistake than many who are involved with bodybuilding make, however, is that they fail to do any type of cardiovascular work at all. This is a bad idea because first, cardio work will help you keep fat gains to a minimum, and because second, it can actually speed with your recovery, if done in the right manner. Cardio To Help You Build Muscle The first thing you must asses when determining which type of cardio is going to help you build muscle is what your own individual recovery is like. If you are the type of person who does a heavy workout and then feels exhausted for a day or two after, chances are your recovery isn't quite as good as it could be. This then theoretically means that if you were to go into the gym and perform a cardio session that was aimed at improving performance, you would require even more time before your next lifting session. Since your aim is to maximize your ability to build muscle, this is not what you want to do. So, if you know already that you are not a person with a good recovery system, you will need to keep cardio training light, and only do what is absolutely needed. In this case, two, twenty minute sessions of moderate paced walking should do the job nicely. If you feel like you must jog, do so, but keep it very light. Sprinting and Building Muscle Now, what about those who have a higher recovery abilityall These are the types of people who can perform an intense workout session, get in some good meals the rest of the day, and be ready to go again the very next day. These individuals can handle a slightly more intense cardio program since their body is capable of supporting more exercise. In this case, sprinting cardio can actually be a smart move because it's been shown to really ramp up that metabolism, which, if you eat enough food, will help increase the rate of protein synthesis and muscle building. BUT, one very key thing to keep in mind here is that you should be counting your sprint sessions as leg workouts. So, don't do a leg workout, followed by a sprint workout the next day, followed again by a leg workout, and then finally take a day off. That will be too much for the body to handle. Instead, incorporate sprints on your upper body lifting days so that you still get those off days as off. It really cannot be stressed enough how much entire days of full rest should be utilized. You're far better off to increase the difficulty on your designated hard days, then try and spread it all out over the week so that each day then becomes a somewhat hard to very hard day. Designing a program in that fashion is what will surely end up causing overtraining to set in. So, don't neglect your cardio if you are trying to build muscle, but don't overdo it either. Take a good look at your own individual recovery system and then design your program appropriately.