Last week I had a conversation with a friend after my studio cycling class. He remained in the room after everyone had left, his long legs burning calories while I cleaned the room. He’s my height—six-three—but easily has a solid 30 pounds of muscle over me, which makes sense given he spent years as a world-class rower and is currently a premier wife-carrier.

We talked about our respective obsessions with fitness. Turns out we both grew up overweight, with big ears—perfect targets for bullying, longtime victims of schoolyard taunting. At some point we grew quickly and thinned out, applying the frustrated energy of being a harassed youth into an obsession with movement that continues unabated—if anything, we’re more driven now—three decades later.