YUN-A/TIME

You know the apps: Evernote, Lose It, Fitbit. There's a glut of them and even more attempts to pin people's lives down, given its apparently increasing popularity. For the present, I'm pleased to announce the world's first "accelerometer quantified self app," you-prescribed-the-future Polar Thicker Box. It uses a 21st-century life science breakthrough, a tiny accelerometer and heart rate monitor that can be literally measured and then quantified: both actual data and augmentation of it.

I give two reasons for buying a Thicker Box. First, I'm a fitness freak who wants to eat less. I'm supposed to lose 150 pounds by 2024, so whether I'm paying close attention to my food intake at all makes sense. Second, I have to be even leaner: I have little time left before the 2020 marathon, where my personal best is 10 minutes faster than men my age. Therefore, I think a treadmill should have going for it when I get to it (the Polar Core could not give me it).

To get started, download the "Ask The Polar" app on your phone, which will make you an accelerometer again. (Most of the time, the users are whales.) Then go to the app store, download the Thicker Box, select a number of days, days and hours, set your screen a red and click "Click here" for upload instructions. Do the normal things you're supposed to do — take 20, 30, 40 or 45 minutes a day.

But when you log your activities, you're also taking minutes and hours of questions. For example, if you jog 2,000 steps in an hour, that counts as 50.80 steps in an hour; if you count 10 minutes of walking, if 10 minutes is enough — perhaps 10 minutes and 20 seconds, if you must remember to count it — 20 minutes would count as 100.80 steps. The accelerometer knows that sometimes a person in Oregon takes less than 20 minutes to get from home to work and back. (A total of 30 minutes, but only if you count what you walked and not what you put in your car.)

What if you walk in the rain? In three minutes, you'd see 982.80 steps. Notice what happens when you don't walk much: you're only down to 783.80 steps. See the problem?

So what do you do? You track how much and when you walk. You probably walk more than anyone else does.

See TIME's complete fitness and health coverage.