That’s me on the left.

I didn’t pee myself. I just sweat that much climbing 4,000 or so feet to the highest point above Santa Barbara. See how Marcus really isn’t sweaty and looks totally comfortable? He does this ride on his lunch break all the time—often while taking phone calls.

Marcus is difficult to schedule. He’s a Harvard M.D. who runs a busy biomechanics lab. He’s an involved dad and husband, and a globe-leading expert in injury prevention. But he’s also a former professional triathlete who practices what he preaches about freedom of movement. I was never going to get him to sit still for the forty-odd interviews it would take to write a book about him. So every time I landed in Santa Barbara, I rented a bike instead of a car. I got Marcus to wear my earbuds as we rode, with my phone in his pocket recording. I wrote interview questions on one of those cardboard to-go coffee cup sleeves that I rubber-banded to my handlebars.

The things Marcus said on those rides changed my life. Motion capture, physiology, how to manage our bodies to move with joy … I piled the lessons of his life into a book called Ballistic (which, as of about six minutes ago, you can pre-order!). Ballistic’s 90,000 words. Meanwhile, the writing and editing process left a wee bit extra, about 100,000 words, on the cutting room floor. Some of it, I believe, is funny. Some of it is insight from brilliant people like Marcus. All of it is was gained through sweat.

Writing Activity is the place I’ll share, for free, the many things I learned that aren’t in the book. Come along for the ride and I’ll try to keep up.