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.