Q: commentary on Q&A#58.To say that anything more than moderate cardio is muscle destroying is not true. Its not the cardio thats responsible for muscle being destroyed,its not eating enough calories which is the culprit. The more cardio one does the more one should eat.Professional hockey players and other athletes do a lot of intense cardio yet they dont lose muscle.

A: I agree with you 100% that if you eat enough to maintain your weight, then excessive cardio will not destroy muscle. But if you eat enough to maintain your weight it means you are not losing any fat either. At least not at any significant rate, and especially as you drop below 15% body fat. And fat loss is the primary reason why most non-athletes do cardio. On the other hand if you are undereating and are losing weight, then excessive cardio becomes catabolic. The degree of catabolism will again depend on several factors, including your body composition, diet, speed of weight loss, health, genetics, training routine, etc.

Again, I am not suggesting that anyone avoids cardio. What I am saying is that it is not the most effective fat-burner available because it becomes catabolic (muscle-destroying) during caloric deficit (undereating to lose weight). I suggest that you instead focus on having a good diet and weight training and supplement with moderate cardio for optimum long-term weight/fat loss.

Another point is to not compare an average person to athletes. Athletes, at least at professional level, are far more genetically gifted than an average person. Plus they have access to top of the line facilities, diet, trainers, supplements (including not necessarily legal ones), etc. However that's not the crux of the matter anyway. The main point I want to make is that cardio does become catabolic when dieting to lose weight.