Marcus was the kind of man who turned exercise into a personality. We had been married six years, and somewhere in the middle of them he discovered fitness the way other people discover religion. The closet filled with foam rollers. The kitchen filled with protein powder. And his wrist acquired a watch he treated like a second heart, one that counted things the first one couldn't be bothered to.

I teased him about it constantly. He had set us up on a shared fitness account so we could "compete," though we both knew the competition was a formality. I closed my rings on a good week. He closed his every single day, including the day he had the flu, which I still think about. He was proud of that little app. He'd hold his wrist up at dinner and announce his resting heart rate like it was a stock price. That pride is the only reason I ever saw what I saw.

It started with the small things, the way it always does. He began charging his phone in the kitchen instead of the nightstand. He started showering at night, which he'd never done in his life, a man who had argued for years that morning showers were the only civilized kind. When I asked about the late nights at the office, he had answers ready a half-second too fast, the way you do when you've rehearsed.

I didn't go looking. I want that on the record, even if there's no one keeping it. I'd had a bad stretch of insomnia that month, lying awake doing the math on a marriage that had started to feel like a roommate agreement. One of those nights, restless and small, I opened the fitness app just to see if his sleep tracking might explain why he was always so tired lately. I scrolled back through the week of activity rings, half hoping the data would reassure me.

It didn't.

There, on a Tuesday, was a workout. A logged session. "Functional Strength Training," forty-three minutes, started at 2:04 in the morning. His heart rate had climbed into a range he usually only hit on his Saturday runs, then held there, then slowly come back down. I stared at the little graph, the cheerful red line rising and falling like a hill.

I remembered that Tuesday. I remembered it specifically, because I'd woken up around two with a dry throat and reached over, and he was there, breathing slow and even beside me. The next morning he'd complained he slept badly, said he'd been dead to the world but woke up sore. Dead to the world. Forty-three minutes of his heart pounding while I lay three feet away, certain he was asleep.

I am not a stupid woman. Marcus was not in our dark bedroom doing kettlebell swings at two in the morning. He had started the workout himself, deliberately, the way he started every session, because tracking the data was reflexive for him by then. He logged everything. He had logged this.

I didn't scream. I didn't wake him. I sat on the edge of the bathtub with the phone glowing in my hands and felt the floor of my life quietly drop a few inches. I went back further. There were others. A Thursday. A Sunday afternoon I'd been told he was at the gym, except the gym sessions had their own honest, boring rhythm, and these did not. The body doesn't lie even when the man wearing it has made a career of it.

When I finally asked him, days later, I didn't bring the phone. I just said I knew about the late workouts, and I watched his face try on three different expressions before it settled on the truth. Her name was a coworker's. It had been four months. He cried, and I noticed I felt nothing, which is its own kind of answer.

The thing that stays with me isn't the affair. It's that he handed me the proof himself, every time, with the same casual tap he used to count his steps to the mailbox. He was so addicted to being measured, to having a record of his own exertion, that he couldn't stop logging the one thing he most needed to hide. He wanted credit for the effort. Some part of him wanted it written down.

I closed his account off mine the day I moved out. I left his rings open and uncompeted. Let him close them alone now. Let the watch keep its faithful little record of a man who could account for every heartbeat except the ones that mattered.