Learn why the fat burning zone is a misnomer and what exercisers should be focused on instead.
San Diego – October 13, 2009 – Perhaps the most popular exercise myth is that there is a specific range of heart rates in which your clients must exercise to burn fat. Many people mistakenly believe they should not exercise above a certain heart rate, as if it were bad to run or bike with intensity. Target heart rate has become a buzz phrase. Even many cardio machines in gyms display a “fat-burning zone” on their panels, encouraging people to exercise in a specific heart rate range. But do you really have to exercise in a specific heart rate zone to lose fat? And what happens if you venture out of that zone?
The research, presented in the October issue of IDEA Fitness Journal, sheds facts on the following:
Since more fat is used at low exercise intensities, people often assume that low-intensity exercise is best for burning fat, an idea that has given birth to the “fat-burning zone.”
However, while only a small amount of fat is used when exercising just below the lactate threshold, the rate of caloric expenditure and the total number of calories expended are much greater than they are when exercising at a lower intensity, so the total amount of fat burned is also greater.
San Diego – October 13, 2009 – Perhaps the most popular exercise myth is that there is a specific range of heart rates in which your clients must exercise to burn fat. Many people mistakenly believe they should not exercise above a certain heart rate, as if it were bad to run or bike with intensity. Target heart rate has become a buzz phrase. Even many cardio machines in gyms display a “fat-burning zone” on their panels, encouraging people to exercise in a specific heart rate range. But do you really have to exercise in a specific heart rate zone to lose fat? And what happens if you venture out of that zone?
The research, presented in the October issue of IDEA Fitness Journal, sheds facts on the following:
Since more fat is used at low exercise intensities, people often assume that low-intensity exercise is best for burning fat, an idea that has given birth to the “fat-burning zone.”
However, while only a small amount of fat is used when exercising just below the lactate threshold, the rate of caloric expenditure and the total number of calories expended are much greater than they are when exercising at a lower intensity, so the total amount of fat burned is also greater.
What matters is the rate of energy expenditure, rather than simply the percentage of energy expenditure derived from fat.
In short, this means that the highest rate of fat use during exercise occurs when you are working at a hard aerobic intensity that typically corresponds to the lactate threshold.
“Since people use only carbohydrates when exercising at a high intensity, does that mean that if they run fast or take a high-intensity indoor cycling class, they won’t get rid of that flabby belly? Of course not!” says Dr. Jason Karp, author of the article. “Despite what most think, people don’t use fat during exercise to lose fat from their waistlines. Have you ever seen a fat sprinter? Sprinters primarily train anaerobically, never using fat during their workouts. Yet they’re still very lean. Carbohydrates are actually the muscles’ preferred fuel during exercise.” For fat burning and weight loss, what matters most is the difference between the number of calories you expend and the number of calories you consume. Fat and weight loss is really all about burning lots of calories and cutting back on the number of calories consumed. For the purpose of losing weight, it matters little whether the calories burned during exercise come from fat or carbohydrates. How people become better fat-burning machines is by enhancing the metabolic profile of their muscles.
For those who want to burn fat and lose weight, high-intensity exercise will burn more calories both during and after their workouts and will also increase the muscles’ ability to use fat. People need to stop worrying about staying in their fat-burning zone—because there’s no such thing! Its good old-fashioned math: caloric output needs to exceed their caloric intake!
You can access the full “Exercise Rx” article on the fat burning zone in the IDEA Online Library: http://www.ideafit.com/fitness-library/the-fat-burning-zone
Source: IDEA FITNESS JOURNAL, Oct. 09 (p.23)
