Many people who are seriously into weight training shy away from doing cardio exercise because they think that it will eat away at their hard won muscle mass. While there is a valid concern for those thinking of running a long distance marathon, most of these fears are unwarranted. Basically, the concern is that as you are running, the body may run short of fuel in the bloodstream for immediate use. Although the body has a mechanism for replenishing energy by breaking down fat deposits, this doesn't always happen quickly enough. The body compensates by breaking down proteins to use some of the amino acids for fuel. Therefore muscle is wasted.

While this basic analysis is correct, the body builder's fears are exaggerated. A short run of say twenty to thirty minutes, especially before lifting, will not break down hardly any muscle mass. Almost al the fuel used will come from what is already present in the blood stream and the energy stored in the liver. This is especially true if you ate at least a moderate high carb meals a few hours before. Actually, a good meal of complex carbs fully digested followed by a 20 minute run is an excellent warm up for a good hour of lifting in the weight room. This is a prime reason to run. It warms the cardiovascular system up for your lifting routine. You will get better workouts and with better workouts, better gains. Following this logic, a light to moderate run will actually help you to gain muscle rather than lose it! But the warm up should not be the only motivation for cardio exercise.

There are several outstanding reasons for adding cardio to your regimen. Cardio is the best way to exercise your heart and lungs, it is the most efficient way to cut fat, and it will boost your metabolic rate more naturally and efficiently than any pill on the market. So how much cardio should you do? That is a hard question to answer. Some suggest that you could start to lose muscle after about a half hour of running. Though they may be literally correct, you should take this with a very large grain of salt. The muscle that you lose even after an hour run is miniscule. Furthermore, since you train with weights on a regular basis, you are continually sending signals to your body to save and to build more muscle. Lifting and running done on a regular basis will condition your body to efficiently handle both the running and the body building. Essentially, when your body is conditioned, what is likely to happen is you still lose a miniscule amount of protein after a run of an hour or so, but your body adds that protein back in a short time. A hardcore professional body builder trying to bulk up for the next Mr. Olympiad may think twice about running that much, but you and I could do it without any net loss over the long run. The only real issue is whether your gains could slow by a margin of 2 - 3% or so. The benefits of cardio to your overall health to your energy level is well worth a theoretical miniscule slowdown, and it is the best and most natural way to get cut.

Cardio exercise has significant health benefits and should not be avoided for those overly concerned with a muscular physic. The truth is cardio actually improves physic because it cuts fat from your body and enhances definition of your muscular build. The substantial benefits gained by cardio are more than worth any small decrease in muscle building. Anything up to one hour of cardio training when combined with a regular lifting program will provide a well balanced program for both physic and health.