Killing the Sacred Cows of Fitness: The “Fat Burning Zone” in Aerobic Exercise is the Best Way to Burn Fat.

I don’t want to watch my life go by.

I don’t want to be an a casual observer sitting on the porch sipping lemonade.

I want to be in it; be an active part of it. Do things. Go places. Cycle. Hike. Climb. Travel. Run with my dogs. Play some basketball. Be lean, flexible, agile. Feel 30 when I’m 60.

Get it?

But I was a long ways away from that a few years ago and partly because I followed what I thought was the “truth” about health, fitness, and wellness. It was what I had been taught.

I’m professionally trained as a physical therapist with over thirty years of experience in sports and orthopedics. And some of that training included exercise concepts and nutrition concepts that were promoted and supported by the medical community and even The Food and Drug Administration of the United States Government.

So, how wrong could they be?

Terribly.

I’ll explain the misconceptions, the myths, the half-truths and yes, even some out-right lies. I’ll go over common mistakes people make in their well-meaning attempts  at getting fit & healthy and layout some other options for you to follow. Some of those options are empirical – based on my observations and experience –  and some rooted in science.

My purpose is to help as many people as I can get fit, healthy, and learn how to stay that way well into the “golden years”.

So let’s start with “killing the sacred cows of fitness” – the seven most talked about, most common things you’ve probably been told to do to get healthy and fit and, well, are just wrong.

The “Fat Burning Zone” in Aerobic Exercise is the Best Way to Burn Fat.

“Can I ask you a few questions?” said Bree, the girlfriend of my guitar teacher, Jim.

I had just arrived for a  lesson and Bree was perched on the edge of their sofa. Upright, alert, ready to go.

“She’s been dying to ask you this stuff man,” said Jim with a laugh.

“Sure. What’s up?” I said.

“Well, I want to lose some weight and, you know, there’s so much out there on the Internet and stuff and it’s so confusing and there’s just so much to go through,” she said.

“Yeah, I know. It’s tough. How can I help?”

“Well, I was thinking of first counting calories and I have an elliptical machine here and so I was thinking that if I did those two things, that might work,” she said.

“Well, that depends. Let’s talk about the elliptical first. Tell me what you planned on doing.”

“I was thinking of some basic cardio, you know, maybe 30-45 minutes or so,” she replied.

Cardio. There are a few words I have banned from Fusion. Cardio is one of them. Workout is the other.

“You know, cardio is a really misused term. Think about it. Any exercise is “cardio” if it makes your heart work which it should. I think what you mean is an exercise that achieves a steady state of an elevated heart rate. I call that “Steady State Endurance” training or SSE.  Of course, it’s easier to just say “cardio” – a short hand – but it’s also really inaccurate. And, the steady state has a much lower return in terms of energy expenditure unless you’re interested in a few hours at a time. You’ll burn some calories in 30 to 45 minutes but not much and not for very long afterward either,” I explained.

“Really? I thought that cardio was what you were supposed to do to burn fat?”

And there it was. Myth numero uno.

“Yeah, I know. You and about a gazillion other people. But, I’m not saying that it won’t help you. What I’m saying is we all have a certain amount of time to invest in exercise and anything you can do to maximize that time, I think, is worth looking into.”

And with that, off we went into the land of interval training.

Interval Training

Interval Training, sometimes referred to as High Intensity Interval Training or HIIT, is a special form of “cardio”. And it’s not easy. Just like most things in life, if it’s worth anything, it’s usually hard.

If you’re going to spend 30 minutes on an elliptical machine, my two cents, use HIIT. You’ll use a bit more energy during the thirty minutes but here’s the hidden benefit: you’ll burn up to 37% more calories over the next 14 hours.^[1] And other research has shown 10 one minute high intensity cycling intervals three times per week is just as effective as several days of much longer and slower cycling.^[2]

Uh-huh. Talk about about a return on investment.

And this is true for any form of HIIT. Not just on a bike or treadmill or elliptical. You can take almost any Fusion Element – what we call our training routines –  and turn it into a fat burning session.

So, say you spend thirty minutes on a bike or elliptical doing a SSE type thing. You might be reading a magazine, talking on the phone. You think you’re doing some real work. You’re not. Caloric burn will be maybe 250 calories – depending on your body weight. And when you get off, that’s it.

Now, if you spend that same 30 minutes kicking your own butt with HIIT, you’ll boost the burn to about 350 and then add another 130 over night. So that’s now 480 calories. Now, you do it again the next day; the next day; the next day. After four days, you’ve churned through 1920 calories compared to 1000 using the old “cardio” method. See?

But, here’s the thing. HIIT must be performed at 70-80% of your max VO2. Now, most of us can’t measure our Max VO2 so instead, use your heart rate.

For me, that’s right around 150 beats per minute. And I often do this for 30 to 40 minutes. I have to hang up my training gear outside because it looks like it just went through the washing machine. Dripping wet.

Does “Cardio” Have Magical Fat Burning Qualities?

“Cardio” isn’t bad for you or a waste of your time. In fact it’s a key component of a joint conditioning program, but in terms of burning calories, you have to do a lot of it.

The idea that there is a “fat burning zone” seems to have started in the 70’s with the rise of “aerobics”. The idea was to perform a moderately strenuous activity that elevated your heart rate to about 60 to 70% of your maximum and then keep it there for 30 minutes or more.

Some studies showed that at this intensity, more fat was burned for energy than at other intensities of exercise.

And this is where things start to fall apart.

First, a lot of people don’t know what 60 or 70% of their maximum is so they use whatever a treadmill or elliptical or bike shows them which isn’t a very accurate way to determine it. The machines use programs to estimate your heart rate based on your age, weight, and gender.

Second, depending on your fitness level, it might take you fifteen to twenty minutes to actually get to 60-70% of your maximum and then you have to stay at that intensity for thirty to forty five minutes (the fitter you are, the faster you get to fat burning). So, now you’re looking at forty-five to sixty minutes for your session. Not exactly an efficient form of exercise.

Third, scientific studies have proved that exercising at lower intensities fails to burn more fat than exercising at higher intensities when measured over a 24 hour period.^[3]

The bottom line is this. Lower intensity, longer duration exercise burns less fat over twenty four hours than higher intensity, shorter duration exercise.

So why would you want to spend an hour doing something that yields a lower return on your investment than 20-30 minutes?

Usually when I suggest that “cardio” is not the best fat burning method, someone will bring up Lance Armstrong or Michael Phelps and wonder say, “If ‘cardio’ doesn’t burn many calories, then why are these guys are so trim and apparently fit?”

The answer is that they train for hours per day; not 30 or 45 minutes. They have what is called a high “energy flux”. They churn through thousands of calories in a day. Heck, Michael Phelps could have pizza three times a day and not gain a pound from the work he does in training.

Most of us don’t have four or five hours per day to train.

But, we can train intensely in the time we do have.

How Hard Should You Train with HIIT?

So, how do you know how hard you’re exercising?

Basically, you go all out.

Here’s the basics of how to use HIIT:

1. I suggest starting with a stationary device instead of running. Yes, you can use this principle with running and yes, it’s a LOT of joint load. So, unless you’re used to running frequently, I would start with a bike, elliptical, treadmill, etc.
2. Set the resistance so you won’t “out-run” the machine (so you don’t end up pedaling faster than the bike can keep up for example).
3. Spend a couple of minutes at a comfortable pace to increase your vital signs slowly.
4. Then, crank up your speed to full for 15 seconds; then go easy for 45 seconds.
5. Repeat this cycle for 20 minutes (if this is your first time going through interval training and / or you’re most accustomed to long, slow distance then you may want to start with 10 minutes).

If you haven’t exercised at all in a long time or if you answer YES to one or more questions on the Physical Activity Readiness Questionnaire, talk to your doctor before you do anything.

Intensity is the king of fat burning. If you’re going to use “cardio”, ramp up your intensity to get the most out of the time and your body.

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