Saturday, January 27, 2007

DF Tip #24: In Praise of Sprinting

sprintrunWhen was the last time you went outside and ran as fast as you could? If you're like most adults, you're probably groping for a memory that's at least a couple of decades old. You might remember a more recent incident if you take public transportation regularly or if you're the father of a three-year-old with Joyner-Kersee-esque foot speed, as I am. But the vast majority of us -- dedicated exercisers included -- just don’t sprint.

By "sprinting" I'm not only talking about running at 100% effort. I'd also count any cardiovascular type of movement -- swimming, biking, running, stair-climbing, rowing, calisthenics, even circuit weight training -- that you can perform at your absolute limit for a period of at least 20 seconds. Pushing so hard that 30 seconds leaves you an exhausted, panting puddle. That kind of effort.

I suspect that people avoid this type of exercise for one simple reason: it's just too darn hard. Sure, we know hard work is important when we exercise, but there seem to be certain types of exercise that strike us as just plain excessive. Amongst strength exercises, chin-ups, squats, dips, and weighted lunges generally find their way onto most gym-goers' "Too Hard to Bother" list. The Versaclimber, that upright cardio machine that simulates the action of scaling a steep rock wall, is tops on my own list. Can barely spend five minutes on one of those god-awful things without crying like a little girl.

versaBut there's an irony to avoiding tough exercises: the number one reason given for failure to exercise is lack of time. People have careers and families and if they were to squander three precious hours a week on exercise then it would pose a serious threat to the survival of the species, quite possibly the universe. But my question is this: if people are so strapped for time (which we all are, let's face it), why does anyone spend a single second, for instance, on something as useless as a thigh-adductor machine? And why do so many of these free-time-impoverished people scrupulously avoid the very exercises that stand to do them the most good in the least amount of time?

A correlary to the "too darn hard" excuse is this: I think many exercisers find hard work on the order of sprints, squats, and chin-ups faintly embarrassing. They feel it's uncivilized to sweat or pant or push too hard. Far better to spend twenty minutes on the recumbent bike working up a decorous little sweat. There's a civilized level of effort and then there's being narcissistic, causing a fuss, or just plain showing off. I believe people also see sprinting as dangerous, particularly for the over-35 set: all that huffing and puffing and pounding? Can it really be good for you?

The truth is, yes. It is -- REALLY good for you, and that's the real point of this particular tip. As a fitness guy, I of course applaud anyone's efforts to get up and move, whatever form that movement takes. But it's increasingly clear to the scientific community that exercise needs to be pretty vigorous to have a measurable effect on incidence of heart disease, longevity and the like. There's mounting evidence that interval training (trainer-speak for sprint training) outdoes more moderate forms of cardiovascular exercise in nearly every way that matters: in caloric burn and weight loss, in the release of beneficial hormones, and in the building and maintaining of muscle mass.

Although the number of calories burned during a short- to medium- length session of sprint training is the rough equivalent, or possibly lower, than the caloric burn one gets from a longer session of moderate-pace training, the caloric afterburn from sprinting far exceeds what one sees from slower cardio work. And for fat loss, caloric afterburn (or Excess Post-exercise Oxygen Consumption for us fitness geeks) is where the rubber meets the road.

sallyConsider: your resting metabolic rate -- the number of calories you burn just breathing, digesting, and staying alive -- accounts for 60-80% of the energy you burn on the average day (that figure, and most of the others I cite below, are from Lou Schuler and Alwyn Cosgrove’s terrific book, The New Rules of Lifting.) Your RMR is usually estimated by multiplying your weight in pounds by 11. So, for instance, as a 180-pounder, I burn almost 2000 calories a day just sitting on my tuckus. That’s a pretty good number of calories burned just catching up on my TiVo.

Now, let's compare the metabolic effects of two different types of workouts. Let's say on a given day you put in a pretty decent steady-state half-hour on a cardio machine and burn 250 calories. That's the equivalent of a banana and a couple pieces of string cheese, or a small serving of the average, medium-healthy cereal (sans milk), or an apple and some cottage cheese. Let's face it, we’re not talking about a great deal of chow here. You'd have to spend seven hours on that treadmill at that pace to burn off even a single pound of fat -- and that's assuming that everything you burned was fat, which it probably wouldn't be.

fruit and cottage cheeseFor anyone with more than a couple of pounds to lose, those are some pretty harsh numbers. So say that instead of your steady-state workout, you decide that you'll trust this kooky online trainer guy and try doing sprints. Choosing a form of cardio that won't aggravate any chronic injuries you might have, you warm up at an easy pace for five minutes, then crank up the speed and incline till you're pushing the limits of your abilities for a thirty-second sprint. Then you back it off to a recovery pace for 90 seconds, repeating the work-rest pattern for a total of five sprints. Then you ease off for three minutes at recovery pace and call it a day. Including a warm-up and cool-down, you can get through this really effective sprint workout in 18 minutes. Depending on how you structure the workout, you might burn 50 calories more or less doing sprints on than you would doing the steady-state workout above. But the magic really happens when the huffing and puffing is over: unlike a steady-state workout, wherein your metabolism dips back to its normal level shortly after your workout, your RMR now stays elevated for up to TWO DAYS after a sprint workout. You read that right.

How elevated, you ask? That's hard to say: it really depends heavily on how hard you push yourself during your workout. But even if your RMR stays elevated 5% for a period of 24 hours -- a conservative estimate -- your sprint workout burns almost 150% of the calories that are burned doing your steady-state workout. That's a pretty good return for what amounts to a smaller investment of time.

But the advantages don't end there. I've pointed out the physical differences between sprinters and endurance runners before: the former tend to be quite muscular and the latter quite stringy. This is, in part, because sprinting helps build and maintain muscle mass (since your fast-twitch muscle fibers, which grow the most, are called into play during sprinting) and endurance exercise burns through muscle mass (since you don't need a lot of strength and power to jog, so your body breaks down the "unnecessary" muscle tissue for fuel). So in addition to burning calories, sprinting also builds and maintains strength, power, and muscle mass, essential ingredients in looking and feeling good. That additional muscle mass, in turn, burns up more calories, both when you're using the muscles and when you're at rest. To repeat a sentiment I've posted in this space more times than I can count, "building muscle mass" does NOT mean bulking up to massive, bodybuilder proportions. For anyone not chucking around massive quantities of iron whilst regularly whacking synthetic and illegal hormones into their veins, it means looking toned and athletic.

sprint bikeFinally, sprinting just feels fantastic. Or I should say, when you're DONE sprinting, it feels fantastic. Yes, it's hard as hell while you're at it: it burns the muscles, your heart pounds, your urge to stop or slow down is sometimes irresistible, you may even feel a little nauseated. Like I said, fantastic. But you're only at it for about 30 seconds, so a rest period is never far off. And as someone who's spent a fair amount of time working at long, steady state pace workouts AND at sprint workouts, I'd say that for endorphin flow, sprinting beats slow straight-up cardio hands-down. I pushed it pretty hard on my bike early this morning, and I feel alert and charged up even now, seven hours later, right in the middle of my usual afternoon slump. I can feel there's something still going on metabolically as a result of that workout. If I'd gone long and easy, I'd need a nap or a strong cup of coffee right now.

Now, let me throw in my usual ounce-of-prevention for all my gung-ho readers who might think I'm saying that sprinting is the ONE TRUE WAY to fitness and to do it every day all day long. There's a reason that sprint workouts only last 20-30 minutes: they're not only very challenging, they're tough on the joints, too. So if you're doing your sprinting on foot, I'd caution against doing more than three sprint workouts a week. If you're swimming or cycling, you can do as many as five -- but your body will still take a cumulative beating, so take a break if you start to feel achy. Work up to full effort on your sprint intervals over a period of weeks. Don't compare yourself to other exercisers: your sprint speed may be the equivalent of someone else's jogging speed, or vice versa. Remember to pace yourself so that your last sprint interval is as fast as your first. And if after all my exhortations past, you think it's wise to skip a warm up or cool down and jump right into maximum effort, well, I wash my hands of you and your reckless ways.

Start with the simple program outlined above. You can always adjust work periods and rest periods, so the interval system gives you a virtually limitless series of workouts to choose from. Good luck, and let me know your progress!



Anonymous said...

Your'e right. I feel some of the reasons people avoid putting in some more effort are:

1. Most are plain lazy for that kind of effort.
2. Some are scared of the effort (partly true because if not done right, there can be damage to the joints.)
3. It requires more motivation.

BTW, I'll be putting a link to your blog soon. Cheers!

James S. said...

Thanks for the insight on how our body works.

If I do this type of training on a fairly secure cardio machine like a static bike (one of those in which you are kind of reclined) or an eliptic running machine, would that save my joints the wear and pain? Keep in mind I weigh 120kg, so for example I avoid machines like the threadmill.

I am a bit of a steady-trainer as you named it, saves for the detail that I don't mind sweating and working hard. I'll try this method (albeit with some caution the first times) and report any improvements.

Thanks for the tip!

Andrew said...

Hi James: You're commenting on an old entry--hope this response gets to you!

Definitely choose non-impact modalities if you have concerns about joints. The bike and elliptical machine are good choices...a real bike would be my #1 choice just in terms of FUN, but stationaries work well too. Swimming is also great--it's non-impact and also a great upper body workout, too, which most cardio forms are not. Good luck, and let me know how it goes! Andrew