I had arrived late and was scrambling. Where were the weights, and how many did I need? Was I feeling confident enough to grab the 10-pounders or should I risk silent ridicule from my fellow Body Sculpt attendees and retrieve a 4-pound set? “That’s my spot,” another student—short, impressive muscles—snapped. It was my first class, and I needed help. After more than three decades, I wanted my body to do something new and hard, but my anxious mind was not cooperating.

I had started to see it everywhere, the message that women need to be stronger. In May, the writer Casey Johnston released a memoir called A Physical Education, about trading constant diets for weight lifting and discovering herself in the process, a real-life counterpart to Miranda July’s fictional narrator in All Fours, whose journey of self-actualization includes extramarital affairs and kettlebells. This summer, longtime Wall Street Journal reporter turned professional bodybuilder Anne Marie Chaker published Lift: How Women Can Reclaim Their Physical Power and Transform Their Lives, chronicling how a weight training habit pulled her out of a punishing rut. “Psychologists who study sports behavior,” she writes, “say that the intensity of lifting weights actually fuels a rewiring of the brain”—apparently, my mind was going to reap the benefits as well. (Working out with weights has been linked to an improved nervous system in one study and a slowdown in cognitive decline in another.)

Widely different parts of the cultural conversation—from chatter on the morning shows to techy brain-science podcasts—are homing in on the benefits. I saw one amusing video where a male bystander’s smirk turned to bewilderment as a woman picked up dumbbells and started shadowboxing. There are legions of viral videos of this variety. Almost three quarters of adults are trying to eat more protein—many seemingly upping their egg consumption in order to build muscle. Khloé Kardashian just released protein-dusted popcorn. (Protein supports muscle repair and growth after workouts.)

And yet, like every other millennial woman whose preferred mode of exercise is Pilates and a walk through the park, I had only just begun to wonder about those intimidating objects—hand weights, dumbbells, barbells, all the bells—in the corners of the rooms where my low-impact exercise classes took place. I had long thought weight training had nothing to do with me—my goal was to become lean and flexible, not muscular and strong. And for years I had been a runner, a pastime that only felt good after I had finished, filled with endorphins and superiority. But not long ago, I gave it up, facing an awareness of my body’s weak spots. Perhaps I did need to face the bells. New York is my home, but I began training in London, where I was temporarily living—it seemed I didn’t have a moment to lose.