Q: just a comment on question 57. lets say one pound of muscle burns 50 calories.I can burn 50 calories in 7 or 8 minutes doing cardio which is much easier than working out for a month just to gain one pound of muscle.

A: This is exactly why I said I don't like the traditional answer that a pound of muscle burns 50 calories a day.

What happens in your body is constant breakdown and creation of both fat and muscle. It happens around the clock, when you sleep, when you eat, when you exercise, when you rest. It is affected by a million different factors. Doing cardio 7-8 minutes may use up 50 calories, but will those calories come from burning fat or from breaking down existing muscle? Would your body end up in higher or lower metabolic state after this exercise? There are no simple, 100% correct answers to these questions. The answers will be different for everyone.

If you have that extra pound of muscle, it's there for you to guarantee some additional fat burning around the clock. How much I cannot tell you, it depends on all these other factors, from your diet to your exercise routine to your health. But it's always there burning extra fat in the background. And if your body needs to use muscle for energy (as it will do, especially when you are losing weight) that extra one pound of muscle is that much more that you'll have left.

The cardio that you perform, on the other hand, may have a whole different range of effects. If it's part of a moderate cardio routine that you perform while maintaining good diet and not severely undereating, then yes it will most likely burn 50 or almost 50 calories of fat and destroy very little or no muscle. But if you perform this cardio as part of a, say, hour-long intensive run on a restrictive diet, you'd be setting your self up for losing muscle possibly even faster than fat and lowering your overall metabolism.

So not all 50-calorie cardio sessions are created equal. I would definitely say that some of them may work against you in your quest to lose fat and/or to gain muscle. Moderate cardio is GREAT for you. I am not saying cardio is evil. All I am saying is that it is not the most important thing in successful, long-term weight loss because anything more than moderate cardio will have muscle-destroying (catabolic) and metabolism-lowering effect which will work against you.

Moderate cardio may burn 1000, maybe 2000 tops, calories per week (that's 8-16 miles per week of running, for an average person). Anything more than that I wouldn't consider moderate cardio anymore. Compare that to 10 extra pounds of muscle which will burn you (assuming our favorite 50 calories/day estimate) 500 calories per day or 3500 calories per week doing nothing but resting! Hopefully this will help you see why I recommend weight training (ESPECIALLY with a well-designed diet) as a far more effective fat burner than cardio.