This medical writer should run over to the mathematics department

I’m not sure what to make of this:

Runners, listen up: If your body is telling you that your pace feels a little too fast or a little too slow, it may be right. A new study, published online March 18 in the Journal of Human Evolution, shows that the efficiency of human running varies with speed and that each individual has an optimal pace at which he or she can cover the greatest distance with the least effort.
The result debunks the long-standing view that running has the same metabolic cost per unit of time no matter the speed – in other words, that the energy needed to run a given distance is the same whether sprinting or jogging. Though sprinting feels more demanding in the short term, the longer time and continued exertion required to cover a set distance at a slower pace were thought to balance out the difference in metabolic cost, says Karen Steudel, a zoology professor at the University of Wisconsin-Madison.

Look at the first part of the bolded text. If, in fact, running burned a fixed number calories per unit time regardless of speed, then we can pick a number to play with–it would be about 0.2 calories per second for distance runners, but let’s go with 1 for simplicity. This would mean that 100m world record holder Usain Bolt would burn exactly 10 calories in a sub-par 10.00 100m race, while Rippy the Cripple, who takes three times as long to cover the same 100m, would burn 30.
Now look at the next section: “in other words, the energy needed to run a given distance is the same whether sprinting or jogging.” Wait–didn’t we just prove that the slower you go, the more calories you’ll burn per unit distance because your engine is eating up glycogen at a fixed rate?
Also, there’s nothing to debunk here; people have known for years that the faster you run, the more calories you’ll burn per unit time. It was once assumed that the amount of energy burned per unit distance was about the same no matter the running speed; a decent runner clicking along at 6:00 pace would burn about 17 calories a minute, while the same person running a more sedate 8:00 pace would burn about 12 calories a minute, yielding a total consumption of about 100 calories in each case. More recent research suggests that more calories are burned at the faster end, and not only that, intense exercise results in an especially prolonged elevated metabolic rate following exercise stoppage.
I really hope this gaffe was produced by whoever wrote the news release and not the research team.
There’s a lot more I could say about the remainder of the blurb, but I’ll cut myself short and observe only that 1964 is calling and wants its “groundbreaking” information back.

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  1. #1 by Bill from Dover on March 23, 2009 - 1:35 pm

    This reminds me of the time Willie (the Gonzo-like drummer in our once loud and obnoxious rock & roll band – no offense Jim) was speeding to a gas station on our way to a gig. When I asked him why her was driving so fast he said he had to get there before we ran out of gas. Go figure.

  2. #2 by natural cynic on March 23, 2009 - 2:28 pm

    More recent research suggests that more calories are burned at the faster end, and not only that, intense exercise results in an especially prolonged elevated metabolic rate following exercise stoppage.
    but I’ll cut myself short and observe only that 1964 is calling and wants its “groundbreaking” information back.

    Hardly recent. 1960’s is right. And preliminary work might have been done by some Scandinavian in the late 30’s. I think that a good picture of how the efficiency curve in running is is to think of a U-shaped curve somewhat skewed to the right [running speed on the abcissa and calories expended per given distance on the ordinate]. Jogging at a pace slower than the optimal speed consumes more calories per mile. The same thing occurs while running at speeds faster than the optimal. And everyone will have their individual curve.

  3. #3 by natural cynic on March 23, 2009 - 2:28 pm

    More recent research suggests that more calories are burned at the faster end, and not only that, intense exercise results in an especially prolonged elevated metabolic rate following exercise stoppage.
    but I’ll cut myself short and observe only that 1964 is calling and wants its “groundbreaking” information back.

    Hardly recent. 1960’s is right. And preliminary work might have been done by some Scandinavian in the late 30’s. I think that a good picture of how the efficiency curve in running is is to think of a U-shaped curve somewhat skewed to the right [running speed on the abcissa and calories expended per given distance on the ordinate]. Jogging at a pace slower than the optimal speed consumes more calories per mile. The same thing occurs while running at speeds faster than the optimal. And everyone will have their individual curve.

  4. #4 by khaulein on March 23, 2009 - 5:42 pm

    Think the dude meant “distance”, not “time”, in the bold sentence.
    “…the same metabolic cost per unit of DISTANCE no matter the speed – in other words, that the energy needed to run a given distance is the same whether sprinting or jogging.”

  5. #5 by khaulein on March 23, 2009 - 5:47 pm

    “More recent research suggests that more calories are burned at the faster end, and not only that, intense exercise results in an especially prolonged elevated metabolic rate following exercise stoppage.”
    Shite. I better start running fast(er) again.

  6. #6 by Julie on March 23, 2009 - 7:39 pm

    Your post offends me. Rippy the Cripple is a good friend of mine and has done nothing to deserve such cruel treatment.

  7. #7 by Joannah on April 1, 2009 - 3:23 am

    I recently came across your blog and have been reading along. I thought I would leave my first comment. I don’t know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.
    Joannah
    http://2gbmemory.net

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