Respiratory Rate Tracking, Sleep, watchOS 8

Respiratory Rate Tracking in watchOS 8 is available now as a public beta and I’ve been using it for 3 weeks on my Apple Watch SE (Review here). You’ll be able to use it in August if you have a Watch Series 3 or newer. Maybe you’re waiting for the Apple Watch 7 in September, I certainly am, that will run it too.

Respiratory Rate Tracking all works well from a technical point of view but I’m just not sure what to do with the data…

Let’s Enable Respiratory Rate Tracking

Respiratory Rate Tracking is a quirky feature in the sense that you enable it on the watch and record on the watch but you can only ever see the respiratory data on your iPhone in the Health App…there’s no respiratory data displayed on the Watch…at least for now. Not even complications that show it.

FYI: The image of the watch, above, shows changes to Total Sleep time.

On your watch go ahead and enable tracking at Sleep App>Set Wake Time>Set Bed Time>Enable Sleep Tracking

You’re done!

Sleep Focus Mode is shown in the image above, I’ll just add that there are some special ways that you can refine the Sleep Focus Mode, and I touch on those here, where you can selectively allow people or apps to interrupt your sleep.

Check Out The Data on your iPhone Health App

There will be little to see here for several days. Sure you might see hourly changes to your respiration rate but that probably won’t give you any insights. Expect there also to be a few gaps in the data when the watch can’t quite get the accuracy it likes but you should expect it to make a good effort at your nightly respiration data when you are moving less. Interestingly the Apple Watch senses your breaths by movements of its accelerometer rather than changes to HRV… that might sound inaccurate but it’s not!

So, here is the sleep & respiration data that I’ve accumulated over the last few weeks. I guess I’m non-plussed by what I see because my breathing rate has been consistent despite some quite varied intensities of training, the odd beer and generally decent sleep durations & quality.

To illustrate the variability of my physiological state in the same period, here we have my rMSSD/HRV and HR/Waking HRrest data for several months and you can see that the last few weeks of each chart’s data vary quite considerably from the upper to lower end of my acceptable range (Software: HRV4Training….use it, it’s good). However, my respiration rate over the same period as stated by Apple is ‘Consistent‘. I would have expected more variation.

Perhaps the only interesting takeout for me was to compare what Apple recorded to my ‘ideal’ breathing rate. You can see Apple is consistently taking my average at just over 15 breaths/min or just less than 4 seconds per breath. I’ve used HRV4Biofeedback software to determine my resonant breathing frequency. Essentially that is the breathing rate that matches the highest rMMSSD (best HRV) reading. My resonant breathing frequency is determined as just under 6 seconds per breath (6 is a normal reading for humans). I’m not entirely sure why my average rate is quite a bit lower than my optimal rate. Can I work to raise it? Or do the averages get impacted by the high rates of breathing from 1-2 hours per day of exercise?

Not sure.

Take Out

My own journey, looking at my respiration rate has thrown up more questions than answers. If you consider yourself an athlete then, perhaps, there’s not so much to see here. Plus you probably haven’t yet been convinced to buy an Apple Watch in any case 😉

This data, however, is going to be more useful for Apple Watch owners when looking at serious medical conditions such as sleep apnoea. Alerting someone that they’ve stopped breathing because of their medical condition and are about to die could, literally, be a life-saver.

Longer-term this is just another metric that Apple is ticking off. Respiration Rate is on a long list of things that need sensing. If Apple’s end-game is to sense them all then they are going to have an awesomely powerful and useful device for pseudo-medial and fitness purposes.