Illustration by Peter Arkle

8:44 a.m. With the Lift affixed near my collarbone, as instructed, I stand tall and press its button for three seconds to �align.� This is how Lumo learns my perfect posture.

8:45 a.m. I open the Lumo iPhone app. It tells me today’s goal is four hours of good posture�a nice low bar to start out with, like challenging me to not get drunk before lunch. I got this.

9:37 a.m. On the subway platform, I assume my usual position of leaning against a dirty green pole. But now I’m self-conscious; is leaning technically bad posture? I stand up straight.

10:45 a.m. Every hour, Lumo says, my goal should be to maintain good posture 40 percent of the time. Who’s that a challenge for, I wonder�the Hunchback of Notre Dame? But after two hours, one at my standing desk, my results reveal I’m no overachiever: 58 percent during hour one and 49 percent in hour two.

11 a.m. I’m ready for Lumo’s big challenge: an hour of coach mode, in which the device buzzes every time I slouch. I stiffen my back and start it up.

11:01 a.m. Buzz. I push my shoulders back.

11:03 a.m. Buzz. How far can shoulders go back?

11:07 a.m. I’m called into a meeting�the cross-office walk earns a buzz�then arrive and stand statuesque throughout. The Lumo goes silent. I’ve discovered the secret.

11:17 a.m. Meeting over. I return to my desk�buzz!�and settle back into my Roman-sculpture impersonation. The only parts of me moving are my eyeballs and wrists on a keyboard.

11:45 a.m. I think I’m breathing better. It’s as if, with my body in alignment, air somehow traveled more smoothly down to my lungs. Is that even how breathing works? I Google it.

Noon. The hour is over. My lower back is tender. My shoulders slightly ache. But Lumo has my reward: I was in good posture for 93 percent of the hour!

1 p.m. I meet a friend for lunch, and we perch on bar stools eating catfish tacos. Lumo reports 3 percent good posture that hour. Whatever, Lumo.

3 p.m. Time for an hour-long meeting, so I turn coach mode back on. I join my colleagues at a table�the first time I’ve sat down while being coached�and Lumo flips out. During the last coaching session, the buzzing was occasional. Now it’s incessant and distracting. I sit unnaturally upright, like a marionette. The buzzing mercifully stops. I lean over to look at a colleague’s computer. Mistake! Buzz. Buzz. I lurch backward, trying to find my equilibrium. Buzz. I shift a smidge. Buzz. I shift again. Buzz, buzz. I can’t stand it any longer and turn the damn coach mode off but continue to sit upright.

4 p.m. Wouldn’t you know it�I had 83 percent good posture during the last hour, the second-best I’ll have all day.

7 p.m. I go home after grocery shopping and look at the last hour’s data�oh, no, only 1�percent good posture! Then I notice a daylong pattern: During hours when I walked more, my posture was worse. My best hour, back from 11�a.m. to noon, contained only 245 steps. My problem is clear: I sit better than I walk.

11 p.m. I’ve had a few glasses of Laphroaig (18 percent good posture this hour) and call it a day. Final tally: ten hours of good posture, with only two feeling like I was living in the board game Operation.