This Fluid Tracking App Tracks Your “fluid Expenditure” Rather Than Your Fluid Intake.
I’ve never been able to master any hydration tracking app. I record the food I eat and the exercise I do, but my drinks are a matter of chance . Did I drink one or two glasses of water at lunch? Who knows. Not to mention, hydration levels depend on your total water intake, not just glasses of plain water. You can drink soup, Diet Coke, or watermelon slices. Most hydration tracking apps forget this, and even if they do, it only complicates the process.
That’s why I was intrigued by the P Water app for iPhone and Apple Watch. It tracks exactly what the name suggests. I’ve been using it for about a week, and so far I’m really enjoying it. I press a button on my Apple Watch when I go to the bathroom, and between stops I can drink as much as I want without measuring or recording anything. If it’s been a few hours since my last visit to the bathroom, the app will prompt me to drink water.
This approach means I get full marks for the water in my soup and Diet Coke because it still hydrates me, and my internal hydration level still triggers bathroom trips. I only spend about 30 seconds a day thinking about the app, and I don’t measure anything. It’s perfect for me.
Why it makes sense to track urination rather than water intake.
The developers of P Water weren’t the first to think of tracking water consumption rather than water consumption. You may have noticed that this approach is sometimes used in medicine, and as a young mother, 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 provide a fairly accurate assessment of your hydration status. For example, this study, conducted on healthy young men, concludes that “urination frequency is a reliable indicator of hydration status over 24 hours” if your bathroom visits are made with a constant “urgency”—in other words, if you sometimes go when you don’t need to, but sometimes hold it for a long time, urination frequency will be a less reliable indicator of your hydration status. This is fairly straightforward.
Tracking water intake, rather than expenditure, 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 has never been particularly helpful , especially considering that people come in all sizes and have different activity levels.
However, if you need to accurately monitor your hydration levels, an app like P Water won’t necessarily do the job. Healthcare providers often request specific fluid volumes when patients keep a so-called “urination diary.” But for a general understanding of whether you’re drinking enough water and producing a normal amount of urine, P Water seems like a handy tool.
How to use the P Water app (with or without Apple Watch)
While the P Water app is convenient to use on the Apple Watch, it also works as a native iPhone app. The full version of the app offers a number of convenient features, such as the ability to “record a urination” by long-pressing the icon on the home screen or swiping down to view Siri suggestions.
I only used the app’s most basic features—mainly logging my toilet visits—but there are other options in the settings. You can add notes for each toilet trip or even use “stealth mode,” which removes the word “pee” entirely. (Alternatively, you can also tell the app to use the word “pee.”) While the basic features are mostly free, some of these bonuses, like stealth mode, require a subscription ($4.99 per month or $39.99 per year).