Cardio-vascular exercises, cardio for short, increases blood circulation in the body and increases heart rate. Cardio is a more effective way to burn excess calories, resulting in fat loss. It is also a great way to "exercise" at the heart.
But the question for most bodybuilders still need cardio is done "before" a weight training session or "after". It all depends on what a person is trying to win and the goal they set for their training.
In the end, you can expect two final results of a training session; Gain of muscle mass and / or loss of fat.
The muscles in our body contain a chemical called glycogen. It is also stored in the liver. Glycogen is a natural reserve of carbohydrates and is available to be easily converted by the body into glucose as needed to meet its energy needs, such as during a weight training session. When all glycogen is exhausted muscle, the body look for alternative sources of energy and start burning the excess fat you are.
Simply, if cardio is done "before" a weight training session, all muscle glycogen is used thus decreasing the energy that can be put to use to lift heavy weights. Since weight lifting does not raise your heart rate as you do cardiovascular exercise, there will be a minimal fat burning.
Perform cardio "after" a workout with weights allow a person to lift more weight at the beginning of the power through an exhausting workout and take advantage of the "heavyweights" to build muscle mass, l The goal of most bodybuilders. A person should be more focused and alert at the start of a weight training session and appropriately would be easier to maintain. Form plays an important role in cardio weight lifting. A good shape is needed while lifting weights to get good muscle growth and prevent injuries. Focus and shape are the key when heavy loads are lifted.
In this scenario, once glycogen is used for weight training, the body look back for other ways to continue to produce the fuel that remains needed. At this point, driving an intense cardio workout will burn more calories at a faster pace leading to greater fat loss. In bodybuilding, this is known as "crushing."
Simply, if the goal of the training session is fat loss, performing high intensity cardio days that are not days of weight training, it will probably be the best option. If the goal of doing cardio balance is to improve his resistance then leave for after a weight training session.
