Tuesday, August 17, 2010

Good Form, Or Running Without Using Your Arms - Sports Science

We had a beautiful, mild, but sunny evening, last night, perfect for trying out one of the experiments from Bobby Mercer's The Leaping, Sliding, Sprinting, Riding, Science Book: 50 Super Sports Science Activities. You have to like that title. Just repeating it is a workout.

As you might imagine, the book is full of sports fun, and the science behind it. Like, did you know, for instance, that pumping your arms while you run, increases the length of your stride, and thereby your speed? I did, because of that one high school semester, when we moved back to Colorado, and I stupidly joined the track team (at 6,000 ft), but my children did not.

To demonstrate this phenomenon to them, I took Mercer's advice, and had them take turns, timing each other, running between two points on a path (a nice smooth path, with nothing to trip on). First, they ran with their arms tied to their sides.

Then, they ran the same distance, being timed again, but with their arms free to pump.

And, sure enough, they ran faster with their arms free. According to Mercer, how fast you run, has to do with your stride frequency (a matter of conditioning), and your stride length (which has to do with proper form). Pumping your arms while running, lengthens your stride, because as you drive your elbow up, it causes your knee to lift higher. When your knee lifts higher, it takes your foot longer to come back to the ground, lengthening your stride.

Having moved from near sea level, to the mountains, back in my high school days, I spent more time on the track team, gasping for breath, than worrying about my stride. But, maybe knowing the science behind it, will give the children one more advantage, I didn't have.

It's great to be a homeschooler.


Christy Killoran said...

I can't imagine running in the mountains. I know that a lot of professional runners move to the mountains to increase their endurance, stamina, etc. and make themselves better overall runners. Fascinating stuff. I can't run around the block in MA without gasping for breath. Sigh.

Anyway, did you also count this as PE? Great experiment.

Ticia said...

I actually do remember that from junior high PE. That and making fists is detrimental to running fast.

Valerie @ Inner Child Fun said...

Running in the mountains -- Yikes! This looks like a great experiment to try... great idea!

Natalie PlanetSmarty said...

I like the experiment, and I remember my first hiking in Colorado - yikes! I have never given much thought to altitude until I experienced its effects first hand.

Unknown said...

Oh, this is a book I MUST have! My Little Wild Man NEEDS daily P.E., and tying Science into it would just be an added bonus!

Annette W. said...


Lady Chadwick said...

We did this last night! Had some company over and they had a great time. After we did the basic no arms vs arms, they had to try all sorts of other ways to see what made a difference (arms on heads, arms at sides, arms behind back.)

So glad you posted this silly fun science.