Thursday, March 17, 2011

Fat Burning? Really?

First off, two apologies:


I apologize if you’re already aware that the “Fat Burning Zone” is a myth. I, like you, thought it hadn’t been taken seriously since the 1980’s. Unfortunately due to more than one recent discussion, I’ve learned this fallacy is alive and well in the exercise community.

I apologize if you believe this nonsense and feel my anger is directed towards you. It’s directed at the knucklehead fitness pro who communicated it to you whose job it is to know better.


The “Fat Burning Zone”, according to its proponents, is a heart rate of between 60-65% of your maximum heart rate. (This presumably is following the guide that your maximum heart rate can be calculated by subtracting your age from 220. The BS that is THAT calculation will be covered some other time.) The proponents and followers of the fat burning zone argue that a relatively low heart rate such as 60-65%, causes your body to burn a greater percentage of calories from fat, thereby increasing fat loss and weight loss.


Problem #1: Following that logic, sitting on the couch watching football is better for me than a circuit of kettlebell swings. Watching football will elevate my heart rate slightly above normal, thereby burning a high percentage of fat calories. An intense circuit of kettlebell swings may get my heart rate up to 180 beats per minute, or pretty close to my maximum. According to the fat burning zone, the kettlebell circuit won’t cause me to lose as much fat as watching football. Uh…OK…


Problem #2: You know how people who are trying to conserve energy always tell you to drive your car more slowly because you’ll save gas? Well you’re body works the same way: if you move slowly, you use less energy. The problem is this: saving gas in your car is a good thing. Saving and storing energy in your body is a bad thing. There is a name for stored energy in your body: it’s called FAT. Drive your car slowly, but move your body quickly – when your body runs out of gas, you’re doing pretty well with your workout.


Problem #3: The concept is short sighted. Let’s assume for the sake of discussion that your body will use more fat for energy when your heart rate is low. You’re still burning way fewer total calories by keeping the intensity down. For example, workout A is trying to get you to burn more calories from fat. Workout A is walking for 30 minutes. Workout A says you’ll burn 100 calories and 50% will be from fat for a grand total of 50 calories burned using fat as an energy source. Workout B is an interval circuit alternating between kettlebell swings and rope slams for 10 minutes. It burns a total of 200 calories and only 40% are from fat for a total of 80 calories burned using fat as an energy source.


Workout B burned 100 more total calories, with 30 more of them coming from stored energy sources (fat), and took 20 minutes less incidentally. But of course, a higher percentage of the minute number of calories came from fat in workout A. Whoop de damn doo – the person doing workout B burned more total calories, more calories from fat, and had an extra 20 minutes in their day.


Now tell me again why the intensity needs to be kept low?


Truthfully, I don’t know the answer to this. I think it still stems from our society’s way for looking for the expedient route instead of the correct route. Walking is easy. Slamming ropes is hard. Let’s look for an excuse to walk. A seated chest press machine is easy. Pushups are not. Let’s sell memberships by showing people our “machines” with soft seats.


Whatever the case may be, you’ll have a tough time convincing me, or any of my clients that doing less work is better for fat loss.