“Hammer! Hammer!” I lost count long ago of how many times I heard that distinct cue from my coach as I hit the final lap of races as a high school runner. Without fail, I’d reach the backstretch of the track with 300 meters to go, and my coach would be standing on the infield, instructing me to pump my arms as I made my way to the finish line. But why the focus on the arms? As I learned thanks to my coach’s unique teaching strategies, driving my elbows back and hammering my arms helped me race faster —and I knew that because I had literally hammered my arms before. Imagine the surprise on my face when coach pulled actual hammers from his backpack one day at track practice to get his point across about the arm swing. He wanted me and my teammates to, well, hammer. Holding one hammer in the right hand and the other in the left, we moved our arms back and forth, pushing our elbows backward and pulling our hands (and hammers) through our hips.…
