The P Water Hydration App Tracks Your ‘Output’ Instead of Your Intake

I never managed to get on board with a hydration tracker. I’ll log the foods I eat, the exercise I do, but I just drink arrive. Did I drink a glass of water or two at lunch? Damn if I know. Not to mention that your hydration depends on all the H₂Oh, you take, not just the glasses of clear water. You can hydrate with soup, Diet Coke or slices of watermelon. Most hydration apps forget about this, but even if they don’t, it makes logging even smoother. more complicated.

This is why I was intrigued by Skin application for iPhone and Apple Watch. It follows exactly what you would expect from the name. I’ve been using it for about a week and so far, I’m a fan. I press a button on my Apple Watch as I head to the bathroom, and between pit stops I can drink whatever I want without measuring or recording anything. If a few hours have passed since my last trip to the bathroom, the app will prompt me to drink some water.

This approach means I get all the credit for the water in my soup and Diet Coke because they always hydrate me and my internal hydration level always triggers my trips to the bathroom. I spend a total of about 30 seconds each day thinking about the app and I don’t measure anything. It’s ideal for me.

Why it makes sense to track urination rather than water intake

The developers of P Water were not the first to think about tracking water production rather than input. You may have noticed that this approach is sometimes used in medical settings, and as a new parent, I remember being asked how many wet diapers my newborn produced each day.

P Water cites research showing that counting the number of times you urinate per day can give a pretty good estimate of how hydrated you are. For example, this study on healthy young men concludes that “[Void frequency] is a reliable index of 24-[hour] “hydration status” as long as bathroom visits are a constant “urgency” – in other words, if you sometimes go when you don’t really have to, but sometimes hold it off for a long time, your pee count will be less reliable as an indicator of hydration. It’s pretty obvious.

Tracking output rather than input takes into account not only the different sources of water in your diet, but also different hydration needs. For example, the “eight glasses of water a day” rule was never particularly goodespecially considering that people are different sizes and may have different activity levels.

That said, if you need to monitor your exact hydration, an app like P Water won’t necessarily do everything you need. Medical providers often request specific amounts when they ask people to do what they call a “urination diary.” But to generally know if you’re hydrating enough to pee a normal amount, P Water seems to be a handy tool.

How to use the P Water app (with or without Apple Watch)

While it’s convenient to use P Water on an Apple Watch, it also works like a regular iPhone app. The full app offers convenient actions, like having a “record a pee” option when you long-press the home screen icon or swipe down to see Siri suggestions.

I only used the most basic features of the app (recording bathroom visits, basically), but there’s more in the settings. You can enter notes for each pee, or even use a “stealth mode” that removes the word “pee” entirely. (On the other hand, you can also lean in and ask it to use the word “piss.”) While the basic features are mostly free, some of these bonuses, like stealth mode, require a subscription ($4.99/month or $39.99/year).