I admit it: I’m both lazy and forgetful.

So while I sometimes manage to track useful health markers (like, for example, heart-rate variability each morning with the excellent HRV4Training app, to monitor over-training), I also often end up going for days and weeks ignoring them completely.

That’s why I’m particularly enthused about any app that works regardless of whether my brain is engaged, like AutoSleep for Apple Watch and iPhone.

Unlike other Apple Watch sleep trackers, this one doesn’t require me to actively tell it when I go to sleep and wake up, yet it’s surprisingly accurate nonetheless. Even better, as I only wear my watch to bed some nights, it still works even when the watch is on the charger. Sure, those nights don’t include sleep quality (which the app derives from heart rate and restlessness data from the watch), but it still accurately clocks start and stop times from when I plug in and unlock my phone (something that, shamefully enough, tends to be my last and first actions of the day). And it even correctly subtracts time for early morning pee breaks, as I (like, I think, most people) briefly turn on the screen of my phone when I get up in the middle of the night to see what time it is.

If my trailing average sleep duration closes in on eight hours nightly, I’m well-poised to hit PRs; whereas, if I’m averaging under seven hours (or, worse, six), I’m lucky to get through my workouts at all (and, frankly, equally lucky to just get through the day). When I keep track of that number in my head, I find I overly weight the prior night (or two), and can barely remember how much I slept on any nights even a day or two further back. AutoSleep’s home page serves as a far more reliable reference.

Knowing when to push myself – and when not to – has been key to keeping me training productively and injury-free for long stretches. If you think it might be for you, too, download AutoSleep; it’s well worth the $2.99 cost.