Millions of Americans are pursuing perfection by quantifying themselves.

You’ve passed your exercise goal, Julia - and the day has just begun! The ring spun clockwise with a fiery green swirl and congratulated me on the achievement with this pop-up message: By 9 a.m., my watch had alerted me that my exercise ring was closed. We hopped off a few stops early to walk a mile to the office. Soon, my partner and I were out the door and onto the train. Every step, even those paced inside my apartment, counted. I tossed my digital companion aside while I showered, but it was affixed back in position before the water stopped dripping from the faucet. Snug against my wrist, my watch kept me company as I bounced from my bed, into the kitchen to turn on the tea kettle, and back into my bedroom to get dressed for the day’s first workout: power yoga.

It was 6:02 a.m., and nothing else mattered. If I didn’t start tracking soon, I wouldn’t get credit for the calories I burned or the minutes I stood - the core metrics tracked by Apple’s signature “ring-closing” feature. I slapped the device onto my wrist before I washed my face, brushed my teeth or checked my phone. My coffin-shaped acrylics crawled from underneath the covers, searched for the stop button and quickly found my Apple Watch.

My fitn