When it’s time to shed some pounds, hitting the treadmill’s “fat-burning” preset training mode might seem like an obvious choice. But can a slow and steady power walk really get the job done? It turns out fat-burning cardio may not be as simple as a push of a button.
Why It Matters
The benefits of low versus high intensity exercise have been debated for years, ever since researchers first identified the “fat-burning” zone. The basic concept is that during lower intensity activity, the body is said to burn a greater amount of stored fat for fuel, making it ideal for weight loss. Higher intensity aerobic exercise (also dubbed the “cardio” zone), by contrast, is believed to burn more carbohydrates—a better choice for building cardiovascular endurance Physiology of aerobic fitness/endurance. Chandler, TD. Lexington Clinic Sports Medicine Center, Lexington, Kentucky. Instructional Course Lectures 1994; 43:11-5..
But before choosing one zone over the other, there are a couple things to know about the presets on those souped up cardio machines. First, they’re not from the future. And second, the two zones aren’t all that distinct, research shows Quantifying differences in the "fat burning" zone and the aerobic zone: implications for training. Carey, DG. Health and Human Performance Laboratory, University of St. Thomas, St. Paul, Minnesota. Journal of Strength and Conditioning Journal 2009 October; 23(7): 2090-5..
Fat burning can actually take place in both zones, whether at 67-87 percent of one’s maximum heart rate (high intensity) or at 58-76 percent (low intensity). While the body does burn a higher percentage of calories from fat at a slower pace, more revved-up cardio is shown to blast a greater number of overall calories, particularly during recovery Quantifying differences in the "fat burning" zone and the aerobic zone: implications for training. Carey, DG. Health and Human Performance Laboratory, University of St. Thomas, St. Paul, Minnesota. Journal of Strength and Conditioning Journal 2009 October; 23(7): 2090-5.. So the good news is there are ways to accomplish both—without running in circles...
Some of the most effective fat-burning routines, like interval training, offer the best of both worlds. By alternating bursts of intense activity with intervals of lighter activity, the body oxidizes fat and blasts calories without requiring hours on the treadmill.
Adding strength training to the mix is another great way to maximize fat-burning potential. Research suggests that building lean muscle mass increases metabolism, resulting in more calories burned at rest.
Just remember that a healthy diet is also essential to losing weight—so be weary of going the chocolate mousse-for-mileage rewards route. Delicious, yes, but all-too-often derailing.