Fat Burning Zone is a Myth!

This week’s article discusses the myth of the ever-so popular ‘Fat-Burning Zone’. This myth, which specifies the specific heart rate range you must exercise in to ‘burn fat’, is so prevalent manufacturers of cardio equipment proudly display these age-based ranges on their machines.  However, the fact is, during exercise your body uses both fat and carbohydrates as fuel, thus both fat and carbohydrates are ‘burned’.

Exercising at a very low intensity, such as walking, results in fat being utilized (‘burned’) as the primary source of fuel. As exercise intensity increases the contribution of fat being utilized decreases, and the carbohydrate contribution increases. Because fat is the primary source of fuel utilized during low-intensity exercise, it is often assumed that low-intensity exercise is best for burning fat, thus resulting in the ‘fat-burning zone’ myth. However, while it is true only a small amount of fat is utilized when exercising at higher intensities, it is also true the rate of caloric expenditure and the total number of calories burned are much higher compared to exercising at lower intensities. Therefore, the total amount of fat utilized (‘burned’) during higher intensity exercise is greater than the fat burned during lower intensity exercise.

The key point for weight loss is: ‘Calories In versus Calories Out’. The calories consumed must be less than the calories burned. Also, when looking at fuel sources from a weight loss perspective, it matters very little whether the calories burned are from fat or carbohydrates.

            A great way to perform high intensity exercise and decrease your body fat percentage is to incorporate interval training into your cardio training program. Not only does interval training allow you to improve your fitness quickly; it is also more effective than continuous exercise for burning lots of calories during exercise and increasing your post-workout metabolic rate.  For your next cardio workout, try incorporating 8-12 reps of 30 seconds max effort (increasing speed, resistance, or incline), followed by 2-3 minutes at your moderate pace.

Terrieha Romer is co-owner of RYP Performance, a company specializing in outdoor bootcamps, small group training, one-on-one personal training, program design, and athlete performance training. Terrieha has a Bachelors in Applied Physiology & Kinesiology, a Masters in Sports Medicine, and holds several nationally and internationally recognized fitness-related certifications. She is also a former Track & Field Coach and Strength & Conditioning Coach at the High School, Division I, and Division II levels, in addition to working with elite athletes as a volunteer at the Olympic Training Center in Colorado Springs. Please email any questions and all correspondence to : getstarted@rypperformance.com