Why the fat-burning zone is a myth: the truth about exercise and weight loss
- It is true that at some workout intensities, you will burn a higher percentage of fat than at others, but it’s not because you’re in some mythical zone
- Losing or maintaining weight is still a matter of calories in versus calories out
If you’re the kind of exerciser who constantly checks your heart rate to ensure you’re in the fat-burning zone, you should stop. You’ll probably never meet your weight-loss goals that way. That is because there’s no special fat-burning zone that’s key to getting lean.
Here’s what you need to know about the myth and about the true relationship between exercise and weight loss.
Yes, we know. If you look at the wall charts or cardio equipment in a gym, or listen to many personal trainers, you’ll be indoctrinated about the “fat-burning zone”. The standard advice for getting in this zone is to work out at about 60 per cent of your maximum heart rate.
That level of exertion is relatively low-intensity; most people can talk in complete sentences while exercising at it. Working in this zone, it’s said, will burn more fat and result in greater long-term weight loss, compared with doing the same exercise at higher intensities.
There’s substance to part of this claim. Your body primarily fuels itself by burning a mix of stored fat and carbohydrates. The less active you are at a given moment, the greater the percentage of that fuel mix comes from fat. As your intensity of activity increases, the percentage of carbohydrates in that fuel mix also increases.
