The gym lights dimmed to emergency mode at exactly 10:45 p.m. I heard the front doors lock with that heavy metallic click from the main hallway. Most nights I timed it perfectly: finish my last set of squats, wipe down the machines, slip into the women’s locker room while the last stragglers shuffled out. Tonight the place felt emptier than usual. No chatter from the cardio section. No squeak of sneakers on the basketball court. Just the low hum of the air conditioning and the distant drip of a leaky showerhead somewhere down the hall.

I liked being last. The quiet let me linger under the hot spray longer than...