Intervals & Fat Loss – Part 1

February 1st, 2008 by

I thought I’d post an article that i recently wrote for a print magazine on intervals and fat loss. I’ll just post the first third of the article today and then will update with the other two thirds in subsequent blog posts.

What’s the first thing most people think of when they think of fat loss? Cardio. Yep, hour upon hour of boring, mind-numbing cardio. Why? Because that is what has been ingrained in our heads. You want to lose fat? Time for lots of cardio. Here’s the problem ‚Äì there’s a reason you have to do so much of it; traditional cardio, or rather, aerobic exercise, doesn’t burn many calories to begin with. But the elliptical says you burned 1000 calories in 10 minutes? Sorry, not true. All of these machines overestimate caloric expenditure. There are numerous shortcomings that come with focusing your fat-loss efforts on session after session of steady state cardio, but we’ll come back to that. First, we’re going to look at a far more effective, time-efficient, albeit more intense, approach to fat-loss cardio.

Most people have at least heard of interval training by now. If you haven’t it simply refers to a form of ‘cardio’ where you repeatedly alternate periods of high-intensity effort with periods of lower-intensity effort. Interval training is normally defined by a work-to-rest ratio in which the ‚Äòwork‚Äô component represents the high intensity/sprint component and the ‚Äòrest‚Äô component represents the low intensity/active recovery component. For example, repeatedly alternating a 30-second sprint with a 90-second brisk walk would be an example of interval training with a 1:3 work-to-rest ratio (the rest is 3x times longer than the work). Generally speaking, the specific details of how you set up an interval program are not that important. As long as you work hard, then rest, the specifics are not critical to your success. That said however, to give some more concrete guidelines for fat loss, a 30-90 second high intensity segment and anywhere from a 1:1 or 1:3 work-to-rest-ratio (so 30 seconds on/60 seconds off up to 90 seconds on/90 seconds off) is probably going to be your best bet more often than not. Of course there are times when you can do shorter and longer intervals as well.

Ok so we now know what interval training is, but the big question is, is it really superior to traditional steady state cardio when it comes to fat loss? What about the fact that everyone in the gym seems to do steady state cardio? Well, look around. How many people do you see slaving on the elliptical for an hour every time you’re in the gym … and yet they never look any different. Pretty common observation isn’t it? Here’s the problem with an over reliance on steady state cardio for fat loss. Besides the fact that it’s boring and time consuming, one of the biggest problems is that the more you do, the more you have to do. As you become more aerobically fit, you’ll become a more efficient fat burner. Sounds good doesn’t it? How much fuel does a fuel-efficient car burn? Not much. It gets a lot of output (mileage) for little input (fuel). Same with us. The more efficient we become, whether aerobically or biomechanically, the less energy our bodies have to expend for a given amount of activity.

More tomorrow …