Workout of the Day

Two-Minute Myths: The Fat Burning Zone


The world of fitness is full of myths, over-simplifications, and sales pitches presented as fact, and we’re only hurting ourselves if we base our decisions off of these falsities and misrepresentations. That being said, we don’t all have time to bury our noses in physiology textbooks to figure out what’s fact and what’s fiction. I get it.

Enter: two-minute myths. Two minutes (or less) of reading, one common fitness myth simplified and clarified. I think we’ve all got two minutes to better inform our decision-making, right?

(Start your timers…)

Today’s topic: the “fat burning zone.”

It’s on a poster somewhere in just about every gym, probably with some colored “zones” marked out on a graph with heart rate, age, and maybe some percentages on the axes. The message: if you want to burn fat, exercise in this heart rate “zone.”

Here’s the lowdown: fat, among other things, is a source of fuel for your body. While your body is never 100% using just one fuel source, it has preferred fuel sources at varying intensities of activity. Fat is the preferred source at lower intensities of activity. This means you’re burning fat while you’re walking the dog, sitting on the couch watching TV, and even sleeping. You’ll also preferentially burn fat when you exercise at a lower intensity. However, this is not the only type of exercise that burns fat, and it’s not necessarily the most effective either. Weight loss, at its simplest, comes from a negative balance of energy consumed (food eaten) to energy expended (daily life + exercising). When expended energy > consumed energy, you have weight loss. If you engage in exercise (particularly, resistance exercise) and eat a balance of macronutrients, this weight loss will be mostly fat.

Now the problem with this zone business: while you will certainly burn fat in the “fat burning zone,” you will also burn fat in other “zones,” and higher intensities of training will expend more energy in less time than “fat burning zone” training. Your body has to recover spent energy after high-intensity exercise (like re-fueling a gas tank), and metabolizing fat (“burning fat”) is a major way that it does so -- in other words, after your heavy lifting session, you’re burning fat to recover from your workout while you sit in your car on the way home. So if 20 minutes of high-intensity training expends, say, 3x more energy than 20 minutes of “fat burning zone” training, 20 minutes of high-intensity training has the potential to “burn” a lot more fat. This same amount of energy expenditure might take (arbitrary number) 60 minutes in the “fat burning zone” on the elliptical.

The moral of the story? The “fat burning zone” is nothing and everything. It is a fast run and it is napping in your hammock. Want to burn fat? Eat better, move more, and probably best not to forget intensity.

- PS


  • Sandbag carry - work up to max weight unbroken 150’ carry


  • 12 min EMOM

    • Min 1: 8 box jumps (24/20)

    • Min 2: 50’ sandbag carry (AHAP) + max burpees in 30s