Does Too Much Cardio Burn Muscle?
There is a huge debate around this question. Cardio can either help or burn the muscle depending on your training. But the real fact is that it actually helps more than it burns. It is not just the cardio that you do but it’s also on your diet as well. If you do a lot of cardio and do a strict diet the body will eat the muscle as a source of energy. If the body doesn’t receive the proper protein and calorie intake it will eat it self. With a good routine of cardio it can even help the muscle to grow.
In an article written on Scooby’s Workshop there are three ways cardio helps the muscle:
“So cardio doesn’t burn muscle, but how might it help you GAIN muscle? – Let’s look at THREE ways:
DOMS (Delayed Onset Muscle Soreness) is a common result of intense workouts and doing 20-30min of daily cardio increases circulation and the increased nutrient flow by the muscle helps the muscles rebuild faster.
Not every workout plan has 5 minutes rest between sets, 
some workouts you will need to do to build mass are very taxing to your cardiovascular system. If you don’t constantly work to keep your cardiovascular system running at peak performance there are workouts you just won’t be able to do with sufficient intensity to gain mass.
There are intense weight workouts that double as cardio workouts and these go by several names – hybrid workouts, complexes, etc – and they all have one thing in common, they take compound weightlifting exercises and do them repeatedly for cardio – often as intervals. These hybrid workouts can build muscle and give you a cardio workout at the same time!”¹
How much Cardio is Too Much Cardio?
When you over train your body not only will you lose muscle mass but strength as well. When you train to a point of exhaustion any training done to the body won’t work since the body is too busy trying to recover. So at the end Cardio is not the enemy for muscle gain but the lack of nutrition and recovery.
References
¹https://scoobysworkshop.com/does-cardio-burn-muscle/
