In order to maximize fat loss and minimize LBM loss I am doing 40 minutes low to medium cardio (mostly biking) 5-6 times a week. Using Dietpower to track all vital statistics, I find that all exercise must be compensated with additional calories above basal. So, what is the advantage of doing an additional 40 minute’s of cardio each day when I need to eat more to compensate? Will it speed up fat loss? :read:

that is a good question.
my thoughts are by doing the 40 minutes or pure lipolysis cardio, you're burning pure fat as a fuel. Throughout the day, your body may need more calories then, but it may convert them to glycogen, or it use them to repair torn muscle fibers.

On top of that, exercise allows us to eat more, so we're not starving trying to cut.

In order to maximize fat loss and minimize LBM loss I am doing 40 minutes low to medium cardio (mostly biking) 5-6 times a week. Using Dietpower to track all vital statistics, I find that all exercise must be compensated with additional calories above basal. So, what is the advantage of doing an additional 40 minute’s of cardio each day when I need to eat more to compensate? Will it speed up fat loss? :read:

This is because of the calorie deficit that increased cardio activity, or really any increased activity creates. You see, in order to lose fat, you must have a calorie deficit. That is, you must use more energy each day than you consume in food. That way your body must look to other means of creating energy for your daily activities than simply your food.

There are two ways that you can create a calorie deficit. The first is by simply eating less. When you eat less and maintain the same activity level, then you are getting less energy from food than you used to, and if that is less than the amount of energy that your body demands for the activities that you are doing, then you are at a calorie deficit.

The second way of creating a calorie deficit is by leaving the amount food that you consume the same, and then increasing the amount of activity you do (i.e. increased cardio, or some thing else). So you are still getting the same amount of energy from food as you used to, but your body is now demanding a higher amount of energy because of the increased workload, then once again you are at a calorie deficit.

What many people do is create a calorie deficit by a combination of both decreasing their calorie input and increasing their workload. This is where you need to be careful, since if your calorie deficit is too high (like over 1000 calories a day), then it could be very detrimental to your overall health. You could start breaking down your muscles instead of just losing fat, and so forth. Muscles use over 19 times more calories at rest than fat does, and so if you lose some of your muscle mass, then your overall metabolism (the amount of calories your body needs) goes down as well, and so then when you get to your goal weight, it is very easy to gain fat because your metabolism is lower.

That is why people are so serious about losing fat while maintaining their muscle mass. I hope I made this as clear as possible. If you have any questions about anything I said, please feel free to ask, and I'm sure many people around here including myself will do our best at answering those.

It will speed up fat lost considerably. I'm not certain why, but, from experience, I'll say it makes a huge difference.

I believe one reason is that cardio raises your metabolism across the board, even long after you do it, so it increases the number of calories you burn, over time, so much that most people would have trouble making up the same difference with diet alone.

After all, the less you eat, the slower your metabolism gets, and you run into diminishing returns very quickly. Plus, over time, your body gets used to your diet and shifts your metabolism to accommodate it. If you didn't do any cardio at all, you'd have to gradually eat less and less to create the same fat loss deficit until you weren't losing any fat at all no matter how little you ate.

You can get around this by being very vigilant on your diet, having well-planned recovery ("cheat") meals, and micromanaging very carefully. But if you really cut back the exercise, diet is the only thing you can alter, and if you don't crack it, you won't make progress. Caridio gives you a little bit of wiggle room - another place you can make changes. Diet is still 80% of the game, but that little bit of wiggle room can be priceless.

Of course, there's nothing intrinsic about riding an exercise bike or jogging. Any activity that raises your heart rate will do, it's just that cardio exercise is easier to do more consistently for most people than, say, circuit-training at a high enough intensity to get the same benefit.