An old article from the CrossFit Journal has this same title, and I’d like to give a quick synopsis here if you’re not a subscriber (which you should be).

How many times have you heard that in order to really burn fat, you’ve got to work in heart rate range of 50-70% of your maximum for at least 30 minutes? There’s even convenient charts posted on nearly every piece of cardio equipment in all the traditional gyms you go to (if you’re cheating on us here at CrossFit Hard), so it must be true. Fortunately for us, it’s not.

Yes, it is true that fat makes up the bulk of your body’s fuel for most of your daily activities and in low-intensity aerobic exercise where you’re either working for long periods of time or not breathing exceptionally hard. This fact is where the idea comes from that you must be in a certain sub-maximal heart rate range to maximally burn fat. The problem is that this is a misunderstood point.

If I work at a slow and steady pace for my prescribed 30 minutes on the stairmaster while I watch TV, I might burn, say, 100 calories, approximately 50% of which are from fat. Now, if I do that same 30 minutes at a much higher heart rate (and therefore intensity level), I could burn about 300 calories, of which maybe only 30% are fat, with glucose and glycogen making up the bulk of the rest (a small amount of protein gets burned as well). “See, you burn more fat at an easier pace!” the exercise magazines will tell you. But anyone with some basic math skills can see that more total fat was burned in the high-intensity workout (90 calories vs. 50) than the lower one, and the first workout merely had a greater percentage of calories burned from fat.

Most of you will be thinking at this point, “But our workouts aren’t that long, so there’s no way we can burn this many calories!” This is a forthcoming post in itself where I’ll tell you a bit more about geeky science things like exercise post oxygen consumption and why you get much more bang for your buck with the style of workouts we do instead of watching television on the stairmaster for 30 minutes. For now, though, trust in the programming and hold back your laughter when someone tells you about weight loss and the fat burning zone.

Till tomorrow, get after it!!!

Coach Graham


WOD 051216

What's the last movie yousaw at the theater?

Warm-up 7

200m Run
100 Jumping Jacks
200m Run
100 Mountain Climbers
100m Bear Crawls
100m side shuffle
100m high knees
100m back pedal


Take 15 mins to learn & practice Muscle-ups or Progressions

Metcon (AMRAP - Rounds and Reps)

Complete as many rounds and reps as possible in 18 minutes of:
18 Alternating Dumbbell Snatch (55/35 lbs)
18 Toes to Bar
800 Meter Run

Cut Season Cash Out

2 min max squats

Out of Town WOD

6 min AMRAP
5 Push-ups
10 Situps KB Swings, 53/35
15 Air Squats

-2 min rest-

6 min AMRAP
5 Push-ups
10 Situps KB Swings, 53/35
15 Air Squats


CrossFit Journal: The Performance-Based Lifestyle Resource MobilityWOD