As a runner, I’ve always indulged in VO2 max/interval training when getting ready, training, for a run. So, I became aware long before it was popular that “interval training”, working harder was a highly effective way of not only burning calories and gaining cardiovascular improvement but also created a furnace for fat burning. I know that my clients have busy lives and need the shortest most efficient way to fitness. When supporting my clients with their weight loss, fat burning efforts I’ve always set up cardio programs that include interval, cardio workouts. The following explains quite well why interval training can best contribute to fat and weight loss.
“Fat burning” and “cardio zones” first appeared on exercise machines in the 8Os, pushing the idea that low intensity, long-duration cardio work is what burns fat and that higher-intensity exercise stimulates cardiovascular impovement. While this is true, it’s not the whole truth.
When we exercise at lower intensities, our bodies use a greater percentage of fuel for energy from stored fat. (As you sit there reading this blog, you’re burning mostly fat as fuel.) When you work at higher intensities, your body uses mostly sugar as fuel.
Let’s say you spend 30 minutes on a treadmill or elliptical. If you spent the entire time working at 65 percent of your maximum heart rate, you might burn 350 calories with about 60 percent of them coming from fat ( about 200 calories). If you spent the same 30 minutes working harder, at say 85 percent of your maximum HR, you might burn 500 calories, with about 50 percent coming from fat, or 250. So even though the percentage was less, due to the increase in effort, the total number of calories and fat calories used would be greater.
Let’s get away from calories for a minute and talk about what’s really going on. Exercise isn’t really even exercise at all, that’s just what we call it. Exercise is really just stress that our bodies have to deal with and adjust to.. The more work you do, the greater the stress, the greater the adaptation. When you work hard and burn sugar during your exercise, your body will burn fat later and become better at using fuel all the time.
When weight loss and fat loss are your goals, the recipe is easy. You need to challenge your muscles through efficient strength training, you need to eat clean so your blood sugar remains stable, and you need to challenge your heart and lungs to get better.
This last one, the cardiovascular piece, should be brief and intense. Work anywhere from 65 to 85 percent of your maximum HR range, but be sure to put short bursts of intensity in there (90-95 percent of max HR). These short bursts are essential when it comes to fat loss. You’ve got to tap that anaerobic threshold, the place where your body can’t meet the demand for oxygen. This is extremely stressful on the system, and brings about a whole cascade of hormonal responses, making the body better.
Remember the old adage that you should be able to talk while exercising? Well, not exactly. You’ll know you tapped that anaerobic threshold because you’ll be focusing on working hard and won’t be able to talk. This recipe of strength training, good nutrition and efficient high-intensity aerobic exercise is the best way for anyone to lose fat.
(As always, check with your doctor before starting any high intensity exercise program.)
By: Jim Beatty