WHAT YOUR WORKOUT SAYS about your social class.

Friends came for dinner. A public-interest lawyer, noticing I was bigger, asked what I’d been up to.

“I’m really into lifting weights right now,” I said. “Trying to get strong.”

The lawyer’s wife, a marathoner and family therapist, appeared startled, as if concerned about my emotional state. She looked me in the eye and said, “Why?”

Sociologists, it turns out, have studied these covert athletic biases. Carl Stempel, for example, writing in the International Review for the Sociology of Sport, argues that upper middle class Americans avoid “excessive displays of strength,” viewing the bodybuilder look as vulgar overcompensation for wounded manhood. The so-called dominant classes, Stempel writes—especially those like my friends and myself, richer in fancy degrees than in actual dollars—tend to express dominance through strenuous aerobic sports that display moral character, self-control, and self-development, rather than physical dominance. By chasing pure strength, in other words, packing on all that muscle, I had violated the unspoken prejudices—and dearly held self-definitions—of my social group.

Well, one wouldn’t want to be unacceptably . . . masculine. Plus: “A faster runner abandons you; a stronger lifter hangs out, kindly critiques your form, and waits his turn.” I don’t know about everywhere, but at my gym the folks — male and female — in the “testosterone corner” (as the trainers call the section with barbells and squat racks) are astoundingly nice.