Weight Loss Forum

What I'm saying, fellas, is this...

How can an exercise machine know how many calories you "burned"? There's only 2 ways. First, the the cheaper machines pick an arbitrary weight for a baseline that everyone weighs. (I believe that number is based on is a 154-pound male).

Better machines ask you to plug your age and weight to keep the error rate to a minimum. But what does this information calculate? Your BMR. So what you end up with is your "gross caloric cost" not "net caloric cost".

Gross caloric cost of an activity combines not only the actual calories burning during the activity but also your RMR for the number of minutes the activity is being done. Net caloric cost is how many calories the activity requires above what you burn at rest.

An example of this point given in the American College of Sports Medicine Health & Fitness Journal is that the gross caloric cost for a 160-pound man walking one mile at a speed of three miles per hour is 79 calories while his net caloric cost is 56 calories.

Doug McGuff, MD, in an article: "BODY FAT: HARD FACTS ABOUT SOFT TISSUE" puts it this way:

Why exercise doesn't burn many calories

"Go to the health club and climb on a stair stepper or treadmill. Program the machine by plugging in your weight, select your speed or program and begin your workout. As you plod along on the apparatus you are driven along by the ever-increasing number on the screen that indicates the number of calories that you have burned. Eventually you go long enough to burn 300 calories and you are left with a feeling of accomplishment.

Now, as you wipe the sweat from your brow and catch your breath, let me ask you a question. Why did the machine ask you to program in your weight?

If you answered to calculate how many calories you burn you are right. What you most likely failed to consider is the main reason it needs your weight is to calculate your basal metabolic rate. The average male will maintain his weight on about 3200 calories a day. That is about 140 calories an hour at rest.

So the 300 calories burned are not calories burned above your basal metabolic rate, they are calories burned including your basal metabolic rate. So for your time on the treadmill, you burned about 160 calories above your baseline. If you eat just 3 cookies, you have completely undone about an hour's worth of work.

Think about it...if we were so metabolically inefficient as to burn 300 calories at the rate the exercise equipment says you do, would we ever have survived as a species. The calories burned hunting and gathering would have caused us to die of starvation before we could ever have found anything to eat. At that rate of calorie burn, we would barely have enough metabolic economy to survive a trip to the grocery store.

Most people have accepted blindly the information displayed on exercise equipment and as such have turned exercise into a form of guilt absolution. Have dessert (600 calories of pie) and feel guilty? Just go to the health club and work on the stepper until 600 calories tick by on the screen. Other than the fact that this simply seems pathetic, it also just doesn't work."

That's my argument when I said you had to subtract your RMR from the calories shown that you "burned" to get a truer figure for "calories" actually burned.