Heart rate and exercise
 

I have noticed that many of the cardio machines have the ability to give you your heart rate as you are working out. Some of these machines also have a chart showing the different zones that your heart rate can fall into. I'm a little confused about a couple of the zones...the Fat Burning and Cardio. What is the difference between these two? I want to burn fat of course but I thought thats what cardio was?!?! Can anyone explain this? Tanks a bunch!!!

There may be someone who actually knows the answer to this - I have wondered about it a great deal myself. From what I can figure out, the theory is that lowish intensity for a long period is better for burning fat. After a certain time (I think about 20-25 minutes) the body burns up all of its muscle-stored glycogen and starts to burn fat. The lower intensity is not enough to give your cardio system a real workout to the point that you will acquire more endurance. At a higher intensity it *does* thus the "cardio training zone." Supposedly when you are in the cardio zone you could be burning up muscle instead of fat.

Part of me thinks all of this is a big load of bollocks. Calories in vs calories out should be the gold standard for burning fat and obviously if your heart rate is higher you are expending more energy thus burning more calories. The other part of me thinks there must be something to it or all of those exercise equip companies wouldn't be printing it on their products.:lol:

Trust your instincts, Julia :) -- it's a crock. There isn't any such thing as a 'fat-burning zone' or 'cardio zone'. My personal training textbook had an entire section of the cardio chapter called The Myth Of The Fat Burning Zone. In a nutshell, yes, you indeed burn a higher percent of calories from fat at lower intensities and a higher percent from carbs at higher intensities ...

BUT!!!

You burn the highest percent of calories from fat when you're totally at rest (like in bed) -- a higher percent of almost ZERO calories, that is! Heck of a workout, eh? :lol:

The bottom line is - just as you suspected - the total number of calories burned is the number that matters. Who cares about burning 75% of your calories from fat if you're only burning a few calories?? Big deal! Go for high intensity cardio to maximize the TOTAL number of calories burned from ALL sources.

Weight loss boils down to calories in verus calories out and we want to maximize the calories OUT -- that way we don't have to starve ourselves to create a calorie deficit. So forget the zones on the machines and - by the way - you gotta ignore the calorie readouts from the machines too -- they're usually way too high. :dizzy:

And frankly, I don't trust the heart rate either. I can switch machines and get widely divergent readings. . . Mostly I use it to monitor my cool down, treating the numbers as relative to each other rather than my actual heart rate.