Hey all. The reason I'm writing the following blog is to dispel the myth that cardio can somehow burn up all the muscle you've worked so hard to build. One of the more common concerns gym members approach me with is that they feel like they should be limiting or eliminating their cardiovascular exercise if their ultimate goal is achieving hypertrophy results. As you read on you'll find that that could not be further from the truth. Enjoy!
Myth #5: Doing cardiovascular exercise will burn up all my muscle.
What you should know: Cardio does not burn muscle, it burns sugar and fat.
Studies show that when cardio is added to a weight lifting program there is no decrease in gains. In essence, the addition of cardiovascular activity to the program did not take away from the resistance training program.
Muscles are composed of proteins, and your body would rather not use proteins for fuel. Generally, your body gets between 3 - 5% of its energy from protein. Even during prolonged exhaustive events such as an ultra-marathon, the energy contributed by protein is not likely to exceed 15-18%. On a side note, low carb diets are likely to increase the body's breakdown of protein for fuel, and many recreational lifters use these diets. These diets are not appropriate for an exercise population.
In a possible plus for strength athletes and bodybuilders, studies show a significant increase in growth hormone and testosterone released post cardiovascular activity. Both hormones play substantial roles in muscle growth.