Tuesday, October 02, 2007

Bigger Is Better, Except When It’s Not

Published: September 27, 2007

[It] turns out that there are rules governed by physics to explain why the best distance runners look so different from the best swimmers or rowers and why being big is beneficial for some sports and not others. [...]

The rules of physics say that distance cycling and distance running are for small people. Rowing and swimming are for people who are big. The physics is so exact that when [Dr. Niels H. Secher, an anesthesiologist, exercise researcher and rower at the University of Copenhagen] tried to predict how fast competitive rowers could go, based only on their sizes and the weights of their boats, he was accurate to within 1 percent.

At first glance, a big rower (and elite male rowers can weigh as much as 250 pounds) may seem to be at a disadvantage trying to row hard enough to push a boat through the water. But because water buoys the boat, weight becomes less of an issue compared with the enormous benefits of having strong muscles.

Their bigger muscles allow bigger people to use more oxygen, giving them more power. It’s like having a bigger motor, Dr. Secher said. Bigger muscles, with their larger cross-section, also are stronger. And bigger muscles can store more glycogen, their fuel for short intense spurts.

The same reasoning explains why elite swimmers are big. Great male swimmers often are 6 feet 4 inches tall, and muscular. And because of the advantage that large muscles give for sprints over short distances, the shorter the distance an athlete must swim, the greater the advantage it is to be big. [...]

Distance running is different. Tall people naturally have longer strides, but stride length, it turns out, does not determine speed. Running requires that you lift your body off the ground with each step, propelling yourself forward. The more you weigh, the harder you have to work to lift your body and the slower you will be.

The best runners are small and light, with slim legs. “If you have large legs, you have to move a big load,” Dr. Secher said. “The smaller you are, the better you are.”

Of course, there are a few exceptions to the scaling rules. There was the Australian runner Derek Clayton, who weighed 160 pounds and set a world marathon mark in 1969.

And there is Tom Fleming, who won the New York City Marathon in 1973 and 1975. He is 6-foot-1, and while he ran his fastest marathon, 2 hours 12 minutes, weighing 159 pounds, he ran the Boston Marathon in 2 hours 14 minutes weighing 179 pounds. “I tell people that’s the fat-man record of Boston,” he said.

The tallest elite marathoner today, Robert Cheruiyot, is 6-foot-2. But he weighs only 143 pounds. Most elite male marathoners, [Dr. Michael Joyner, an anesthesiologist and exercise researcher at the Mayo Clinic] notes, are between 5-foot-7 and 5-foot-11 and weigh between 120 and 140 pounds. In distance running, he said, “you just don’t find many big people.” ...


Blogger Harry Eagar said...

Accurate to within 1%? Not impressive for a sporting event, too bad by an order of magnitude.

Back in my sports reporting days, the greatest contest I ever saw in person was a 5,000-meter swimming race.

That takes about 20 minutes. The contestants, both All-Americas, were never more than a head apart during the entire race and they broke the NCAA record by nearly a minute.

It was a dead heat.

One was 6-7 and lithe, the other 5-9 and chunky.

October 02, 2007 9:27 AM  
Blogger Oroborous said...

Seems pretty good to me, considering the variables used in the prediction.

But as you note, some people make their own realities.

October 02, 2007 11:55 AM  
Blogger Oroborous said...

The point of the full article wasn't that researchers could figure out who would win a contest between two seasoned athletes merely by looking at their body types.

October 02, 2007 10:32 PM  
Blogger Harry Eagar said...

Well, what was the point? A 1% difference in the 100 yard dash is 0.1 seconds -- the difference between first and 12th at a top meet.

And he says, 'over short distances, the shorter the distance an athlete must swim, the greater the advantage it is to be big.'

This does not apply to sprint runners. I used to attend the Drake Relays every year. Sprinters are typically muscular -- not necessarily bulglingly so -- but compact.

It was funny to watch Herschel Walker in the 100-meters. He was about twice as big as the next biggest runner. He was good, too, but he never won.

October 03, 2007 12:19 AM  
Blogger Oroborous said...

Ah yes, Herschel Walker. I really admired his workout routine - although not enough to copy it.

Maybe the experts cited in the article are just wrong.

October 03, 2007 2:04 AM  

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