Q: Hi Erika! Long time subscriber 🙂 I just want to know if the notorious “fat burning zone” exists or is it merely a myth? I get mixed reviews when doing research.
Uh…sort of. Let me explain.
There is myth surrounding the fat burning zone as most people understand it, but that doesn’t change the fact that there is – at least, in my mind – a fat burning zone that people should do their best to stay within.
The fat-burning zone, as far as most people know it, is the belief that slow and steady-paced cardio activity is the best way to burn fat. That, in fact, this is the best way to burn fat – slow-paced aerobic activity.
Not quite.
Your body is constantly burning fat for energy. Constantly. All darn day. The amount of energy (also read as “fat,” also read as “calories”) that your body burns will almost always correlate to the amount of activity that you complete within any given time frame. Barring some hormonal abnormality, there’s no way to change that.
During an intense workout, there is a point where your body will no longer use fat for energy, but instead switch over to burning muscle for energy. This is why you see avid lifters who simply don’t do cardio, because muscle is valuable and excessive challenging cardio will eat away at that. (Somehow, the “don’t do challenging cardio” meme was passed around, but the “lift weights! get muscle!” fell to the wayside. Hmmm.) The “punishment” for doing super-intense cardio isn’t “your body doesn’t burn calories as well as it does during your slow-paced cardio;” the punishment is “your body loses muscle,” which is just Latin for “now, your body doesn’t burn calories as efficiently outside of your workouts the way that it otherwise could.” Bummer.
Knowing your maximum heart rate (220-your age= your maximum heart rate) will help you better calculate your zones. For cardiovascular activity, staying between zone 1 and zone 3 (which is to say, working between 40% and 75% of your maximum heart rate) is your best bet… which is also why high intensity interval training is your best bet. It allows you to float effortlessly – jokes, jokes – between your zones, and get the benefit of the higher zones even though you’re only working out to that intensity for 30-60 seconds at a time. It helps you preserve muscle, while still burning fat by staying within that wide range of heart rates.
What is high intensity interval training?
I’m so glad you asked!
High intensity interval training is, quite frankly, training in intervals where you give 110% of what you’ve got for a chosen period of time and then rest for a shorter period of time. This is different from an activity that you’d participate in, giving steady effort and intensity, for a long period of time. High intensity interval training is more time-efficient, more effective and often serves as a great way to develop better cardiovascular strength.
Lifting with proper form, burpees, mountain climbers, circuit training…. hell, even some plyometrics or even some hard work in a weights machine can turn into a HIIT workout quickly and having you in [the good kind of] pain and thanking your lucky stars.
A successful HIIT workout has lots of different components to it, and if you want to get the most out of your half hour (or hour, if you’re so tough) then you do what you can to make sure you’re managing all of those components. And, let’s face it – “getting the most out of your hour” is a polite way of saying “produce results.” Everyone cares about effectiveness, because if your workouts aren’t effective then you’re not going to be producing results, in the form of a changing body. HIIT can definitely make that happen.
9 comments
This was a good post. I always wondered what that “fat burning zone” on the elliptical meant. I always tried to go way higher than that zone to maximum heart rate high. I figured it meant that I was working really hard, burning more calories, which in turn meant burning fat. Does this mean I should slow my role???? Oh and HIIT absolutely works! I completed the insanity dvd’s and saw a huge difference in my body. It wasn’t the drastic changes like on the infomercial but a lot of people myself included could see the difference. Thanks E I follow this blog religiously lol. Like a sits at work all day and reads old posts typa thing lol.
Awwwww. <3
Thanks for the info, this helped alot
Light bulb moment! The treadmill aka torture rack at the gym has different programs..starts off slow and flat and then goes to a thigh burning incline..I actually love it, nothing like the accomplishment ya feel after an hour, knowing ya made it through
“During an intense workout, there is a point where your body will no longer use fat for energy, but instead switch over to burning muscle for energy”
This is completely untrue!! At high intensities you will burn carbohydrate (which is STORED in muscle). Muscle is made of protein and the body generally does not metabolize protein for energy (unless its a starvation situation). Therefore at intensities above the “fat-burning zone” you will burn more calories, but with a lower percentage of those calories coming from fat, per se. At the end of the day, calories are calories. You will only “lose” muscle mass by doing cardio if you are not consuming enough calories (specifically protein) to maintain protein balance.
You’re not entirely inaccurate, you’re just missing a few parts.
“At high intensities you will burn carbohydrate (which is STORED in muscle). Muscle is made of protein and the body generally does not metabolize protein for energy (unless its a starvation situation).”
Sort of. You’re not burning “carbohydrate” stored in muscle, you’re burning glycogen. THAT is the important part – at high intensities, for extended periods of time, and depending on both your diet and your average activity levels prior to the day in question – you can trigger something called glucogenesis (literally, the creation of new glycogen), which will then come from fatty acids but also will break down the protein IN your muscles, because it swipes amino acids from the muscle. Someone who does lots of intense cardio for hours on end on a consistent basis WILL in fact begin to burn muscle. It’s a HUGE part of why figure/bikini/physique competitors with bad trainers will have them bulk and bulk and bulk, only to have a heinous cut down with no carbs and high cardio, with the expectation that they should do MAJOR bulking only with the expectation that they’ll lose most of it in the cutting phase. It’s counterproductive… and, really, stupid.
It’s really hard to nail down specifics as to what and when you can trigger the process, which is why I strayed away from giving them in the post, but I definitely see where the confusion could arise.
Calories are not calories – they don’t all do the same thing in the same body, and you can’t swap out one macronutrient for the other and make it do what you want. The body literally does not work that way.
You will obviously burn more calories with a higher heart rate, but if you’re not fueling your fitness activity enough – which, after attending several sessions on fueling for athletic activity, I can ASSURE you that most people are not – then what? Then you start to lose muscle.
If anyone still believes you cannot build muscle by lifting and doing high intensity interval training, I invite you to Google the American Women’s 4x100m World Record setting relay team.
Hey Erika! What do you think about the military standards and how they might effect women/men in service? It would be nice to see your opinion. Body fat percentage/height and weight limits wise.
Hmmm…sounds like an interesting post. 🙂
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