 By David Otto
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Will The "Fat Burning Zone" Chart On The Cardio Machines Help You Burn The Most Fat?
Anybody who's been on a piece of cardiovascular equipment at your local health club has without a doubt seen the small chart attached to it showing the "cardiovascular training zone" and the "fat burning zone." These two zones according to the chart represent "target heart rates" based on your age that you would ideally train in if you were trying to accomplish either fat loss or more of a cardiovascular benefit.
I won't recommend that you do this because you'd be bored out your mind but if we take an exercise physiology book and do a little reading, we'll find that there are a couple ways we can estimate what's commonly called our "Target Heart Zone" (THZ). Before I get to the whole equation on how to figure that out let's take a look at what else the exercise physiology book will tell us: "you burn a higher percentage of fat for fuel while in an aerobic state at lower training intensities." The reason for this is because when you approach what's called the "anaerobic threshold" your body will burn more and more glucose for fuel and when you cross that threshold your body will burn exclusively glucose.
Now back to the chart you see on the cardio machines. The reason the "fat burning zone" is underneath the "cardio training zone" is because at lower intensities the body will supposedly burn a higher percentage of fat. Simple right, and based on your age, the heart rate you "should" maintain is based on the simple equation of (220 - Your Age) X 60-70%. So if you're 43 and looking to burn fat, according to the chart you would try to maintain a heart rate somewhere in the ball park of 115 beats per minute.
There's another common formula that's used that takes into account your own resting heart rate but for simplicity I won't go there in this article. In just a bit I'm going to give you something even simpler to use that you can gauge intensity by that requires no formula and no counting. Anyway, let's get back to the question that concerns having to be in your THZ to burn fat. Is it absolutely necessary? I've heard people and trainers say so. The fact is that you can burn fat anytime you are in an aerobic state like right now while sitting down reading this article.
What about while doing cardio, do you need to be in the lower end of your THZ to burn more fat? A-ha, now that's a good question that's been receiving scrutiny for quite some time. Yes, from a physiological standpoint your body will burn a "higher percentage" of fat for fuel out of the total calories burned but at higher intensities the body will burn a greater amount of total calories. At higher aerobic intensities, pending you don't cross the Anaerobic Threshold, you'll burn a greater percentage of glucose as opposed to lower intensity training but being that you've burned more total calories, the net effect is that you have actually burned more fat as well. The key word here is "percentage."
You've probably heard the term "interval training" thrown around as it relates to cardiovascular exercise and fat burning. Essentially, you alternate between bouts of high intensity and low intensity training when exercising aerobically. This is where that formula I used earlier comes back into play. For example, you would warm up aerobically for 5 minutes and then work at 80-85% of your "estimated maximum heart rate (220-age) for 2 minutes. Then you would switch gears and work at 65% of you maximum heart rate for 2 minutes. You could alternate this cycle 5 times followed by a cooldown and that would be an example of a simple interval aerobic exercise session. The premise here is that overall, you'll burn more calories and thus more fat with the real clincher being what's called the "after burn effect." Basically, your body will burn more calories, thus more fat in the hours after you complete the session as opposed to working at a steady pace.
So what's better? Working at a steady pace or performing intervals. From my own experience with myself, my clients and what the current research has to offer, performing a mix of the two seems to be the most beneficial in terms of fat loss. However, a beginner with fat loss as a goal wouldn't integrate high intensity interval training into their program until they've first established a training base through steady state aerobic exercise.
I did mention earlier that I would give you a simple method to monitor intensity while doing your cardio and here it is. If you don't have a heart rate monitor and find that taking your pulse at either the carotid artery in your neck or the radial artery in your wrist is too difficult then you can simply use what's called "Rate of Perceived Exertion." Originally called the Borg Scale of Perceived Exertion which is based on a scale of 6-20 you can simply use a scale of 1-10 with 1 being "sitting on you butt doing nothing" to 10 being all out exertion. If you are performing interval training then this is a great method to use, however if you are an athlete or someone looking to be precise then investing in a heart rate monitor that you can wear would be of value to you.
The easy method that I mentioned earlier that doesn't involve math or counting of any kind is the "Talk Test." This is a simple and fairly reliable method to use when performing steady state cardio that can tell you whether or not you are in your THZ. You should be slightly out of breath, notice a definite increase in heart rate but…be able to carry on a conversation reasonably well. If you can't carry on a conversation then you're working beyond the point of where your body is accessing fuel from glucose and/or fat and will possibly catabolize muscle tissue. Not good by the way, however you shouldn't be able to sing your favorite song which of course means your not working hard enough. The reason this is a pretty good method as well as the Rate of Perceived Exertion is because the equations that involve 220 - Your Age (i.e. the "fat burning zone" on the cardio machines) are fairly inaccurate when calculating maximum heart rate and then estimating THZ. Bottom line: forget about the "fat burning zone" and the "fat burning" setting on the cardiovascular equipment.
I do want to close this article out but shift gears for a second and say that aerobic exercise is merely a piece of the puzzle when it comes to fat loss. If there isn't a concern for The Right Nutrition, Moderate Aerobic Exercise and a Concern for Muscle (resistance exercise) then long term results will be minimal to non-existent at best. Best of luck in your pursuit of a fit, lean and healthy body!
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