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There is a common belief that the treadmill is the best cardio modality for burning fat. This belief seems to be supported by various books and internet sites that post charts showing a greater expenditure of calories associated with the treadmill when compared to similar time spent on alternative cardio modalities.

A recent study by Brown and colleagues (1), however, provides evidence that this might not be the case. Eighteen subjects (9 males and 9 females) were assessed while either exercising on the treadmill or the elliptical trainer. The results might surprise you. Researchers found that when exercising at the same rating of perceived exertion (a measure of how hard one is training), there was no significant difference in the number of calories burned between the two modalities.

Fat burning as it applies to aerobic exercise can be boiled down to two basic factors: intensity (i.e. how hard you are exercising) and duration (how long you are exercising). The key point is that with respect to training intensity, it doen’t matter whether you are running, biking, stair climbing, etc.; provided you are putting in the same relative effort, fat burning will be basically the same.

The take home message here is that if you don’t like to run, don’t force yourself to slog through a treadmill workout in hopes of burning a few extra calories. As long as you train at a comparable level of intensity, the differences in fat burning between modalities will be negligible. Given that the most important aspect of any exercise program is adherence (you can’t get results if you’re not training, right?), you should choose a cardio modality based on your goals and preferences–not because it purportedly burns more fat.

Stay Fit!

Brad

1) Brown GA, Cook CM, Krueger RD, Heelan KA. Comparison of energy expenditure on a treadmill vs. an elliptical device at a self-selected exercise intensity. J Strength Cond Res. 2010 Jun;24(6):1643-9.

Set foot in any gym and you’ll no doubt see cardio machines that have charts to help you train in your ‘fat burning zone’. The theory behind the concept is based on studies showing that the percentage of fat used as an energy source is optimized when you train at an intensity between 60 to 80 percent of your target heart rate. But while increasing the percentage of fat burned for fuel sounds like a great way to get lean, it unfortunately doesn’t translate into burning more fat on an absolute basis. The most important aspect of shedding body fat is the total amount of calories burned—not the percentage of calories from fat—and therefore a higher intensity cardio routine is the better choice.

You see, the human body is a dynamic organism and constantly adjusts its use of fat for fuel. This process is governed by a host of factors (including enzyme levels, substrate availability, internal feedback loops, etc.). If you expend more calories than you consume, your body will shift to a fat burning mode and mobilize excess adipose as a source of energy. Thus, from a fat loss perspective, high-intensity exercise burns more fat calories on an absolute basis than lower intensity activities.

Ideally, the activity that maximizes calorie burning is interval training, where short bouts of low intensity exercise are interspersed with high intensity bouts. Interval training not only heightens fat burning during the activity itself, but also increases the amount of calories you burn after the workout is over! This is due to a phenomenon called excess post-exercise oxygen consumption (EPOC). Simply stated, EPOC keeps your metabolism elevated for several hours following training. Moreover, there is an associated increase in the secretion of both growth hormone and noradrenaline—hormones that are integrally involved in the fat burning process—resulting in an increased utilization of fat of fuel. All told, there is both a greater total amount of calories expended as well as a greater amount of fat oxidation following training.

Here’s the catch, though: EPOC is intensity dependent—the harder you train, the more calories you expend following training. That’s why you need to push yourself as hard as you can during your high-intensity intervals, going as close to all-out as possible. For those who have never performed this type of cardio, I generally recommend starting out with an interval ratio of 4:1 (i.e. four minutes at low intensity followed by 1 minute at high intensity) and, as you become more fit, gradually lower the ratio until you are at 1:1.

Although people tend to associate interval training with treadmill exercise, virtually any cardiovascular activity can be employed, including machines such as the stair climber, elliptical machine, and stationary bike. You can also jump rope or perform any number of outdoor activities, too. Just make sure that you are readily able to switch between high and low intensities. In final analysis, you’ll exert a good deal more effort in your training, but the results will be well worth it!

If you’d like to read about the science behind the concept, check out the article I co-wrote with Jay Dawes titled, High-Intensity Interval Training: Applications for General Fitness Training for a recent issue of the NSCA Strength and Conditioning Journal.

Stay Fit!

Brad

Reference

Schoenfeld, B., Dawes, J. (2009). High-Intensity Interval Training: Applications for General Fitness Training. Strength and Conditioning Journal, 31(6), 44-46

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For those who have read my books or attended one of my seminars, you’ll know that I’m a big proponent of performing interval training to optimize fat loss. I was quoted in the current issue of More Magazine as stating that it’s the most effective cardio technique for slimming down. So true!

As noted in the article, the benefits of interval training have been borne out by research. Studies repeatedly show that it has significantly greater effects on reducing body fat levels, producing up to a nine-fold reduction in skin fold measurements. Best of all, interval training requires about half the workout time compared to traditional steady-state cardio training.

The concept behind interval training is simple: intersperse bouts of high-intensity cardio with lower intensity cardio. Pretty much any aerobic modality can be used for interval training. For example, you can choose jogging as the low-intensity cardio and running as the high intensity cardio. Alternatively, you can combine skipping rope with jumping rope. Or you can intersperse jumping jacks with squat thrusts. The possibilities are pretty much endless.

If you’re a beginner, keep the intervals on the longer side. A 1:4 high/low ratio is generally a good starting point. Try to gradually narrow the interval until you’re training at a 1:1 ratio. 20 to 30 minutes a session, three days a week is all you need to do to see terrific results. Be careful that you don’t overdo it, though. The high-intensity nature of the routine can easily lead to overtraining if you’re overzealous. As is often the case, less can be more!

Stay Fit!

Brad

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