The question: The elliptical and treadmill at my gym both have a "fat-burning zone" program. Should I ditch my higher-intensity runs and use that program if I want to lose fat?
The answer: I totally understand the draw of a "fat-burning zone" program. Who wouldn't want to follow a program whose name implies it is the ticket to a smaller jean size?
Although it is true that when you work within a lower fat-burning heart rate zone, a higher percentage of the calories you burn are from fat, the results are not as promising as the name implies.
Why? First, the fat you are burning is mostly the fat stored in your muscles, not adipose tissue fat, which is the fat most people want to melt off their hips.
Even though a lower percentage of the calories you burn are from fat when you work out harder, you actually burn more calories overall and create more of a metabolic demand. Therefore, you are more likely to go into calorie-deficit. Both a high metabolic demand and a calorie-deficit are needed for weight loss. If the fat-burning zone was the only way to lose fat, all sprinters and soccer players would be chunky.
That said, doing something is always better than doing nothing. If your options are a fat-burning zone program or nothing – do the workout, but don't ditch higher-intensity workouts either.
Trainer's tip: Whenever you are discussing how exercise impacts weight loss, the important phrase to remember is: "assuming none of the expended calories are replaced." Exercise will help you lose weight as long as you don't replace the calories you expended. You can walk in a fat-burning zone or run all out for 10 kilometres, but it won't help you lose weight if you eat a cheeseburger and fries afterward!
Kathleen Trotter has been a personal trainer and Pilates equipment specialist for 10 years. Her website is www.kathleentrotter.com.
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