In “Making Stuff,” a new four-part NOVA series premiering  on PBS on Wednesday, October 16, New York Times and Scientific American technology columnist David Pogue explores the material world in making things faster, smaller, cleaner and smarter. In this sneak-peek clip, Pogue learns the secret to faster sprinting. It doesn’t have to do with moving your limbs faster—in fact, analyses done at the Southern Methodist University lab featured here show that professional sprinters and everyday folk reorient their legs at the same rate.

So what determines running speed? The short answer: staying straight and slamming down hard.