The Complete Apple Watch Guide to Understanding The Quantified Self

What is the Quantified Self?

The term quantified self was popular in the mid 2010s as a way of describing metrics that you can track about your body and life. There are dozens of types of sensors, tools, and gadgets that can be used to contribute to the idea of a quantified self including low tech things like scales and measuring tapes but for the most part the term is used to describe advanced sensors. Over time the trend on popularity for the term “Quantified self” has declined and the rise of wearables has taken over.

There should be no surprise that this trend shift corresponds to the release of the Apple Watch which is one of the leaders in the wearables space. With the release of the latest Apple Watch 8 and Apple Watch Ultra, that have improved battery life, continuous monitoring keeps getting easier.

google trend chart showing wearables overtaking quantified self

These days both of these terms are dwarfed in popularity by the likes of “Fitness trackers”. Quantified self still has a more broad meaner as it can relate not just to fitness in the typical sense but can be used for anything that can be tracked. With the continuing advance of cameras and sensors it is becoming increasing possible to do full life-logging across not just fitness but also body inputs and health as well as visual logging of experiences.

daily rings on apple watch

We have covered a handful of trackers on this site but Apple Watch and Apple Health kit are still the go to. After having worn one of them for nearly 4 years with minimal time off it has become a staple for providing daily feedback. The rings history goes back to 2018 in our watch and the Apple Health kit has manual entries for weight and vital readings for more than half a decade. In this article we review some of the top areas of focus that we find ourselves looking at regularly, based off of daily wear of an Apple Watch

Tracking Vitals and Activity For the Quantified Self Using Apple Watch

Activity Calendar and Apple Watch Rings

Fitness activities and the Apple Watch rings are how most people associated Apple’s products with daily tracking. Fitbit has a similar brand awareness as the folks who popularized taking 10,000 steps a day. The accuracy of step tracking for Apple watch is great compared to other top trackers,

For Apple Watch there is a built in workout tracker as well as a simple visualization that showcases how rings have been completed over time. Having a “Perfect Month” which results in a digital badge is still a goal but each month there winds up being at least one day of battery recharging, sickness, travel, or other interruption that keeps at least one of the rings from closing.

apple watch monthly rings

Workout Calendar on Apple Health Kit

While the rings are rings are nice, a workout calendar is useful as well. Rings do showcase this information though, if you have ever asked “What is the green dot next to my rings” that denotes it was a day with a workout. Another version of this is just the workouts calendar which highlights days that have a tracked activity. Typically our preference is to use Strava for this instead as the Strava Premium (see our full review) summarizes a training log well.

Still this view is easy to see how many days we slacked. It is worth noting that the workout calendar treats all logged workouts equally, whether that is a Tennis session, Paddle boarding, a walk, or a 100 mile ride. Using the default exercises also is much easier than using a third party app on the watch to track. The ability to customize the watch display to show things like altitude gained during a run is easier when using the Apple workouts compared to anything else.

apple watch activity calendar

Heart Rate and HRV

The Apple Watch heart rate sensor opens a world of additional information. While they continue to strive for FDA approval on the sensor so that it can be used diagnostically, for the most part even the continuous heart rate can open you to a host of information. A simple check of resting heart rate can easily confirm that a slight cold or the flu is on-coming and every time that we go from sea level up to altitude in the mountains we watch the effects of altitude on an increased daily resting heart rate.

Heart Rate Variability (HRV) is one of the next step metrics and is similar to what others like Whoop bands use for fatigue tracking. To see our full review of the accuracy of Apple watch HRV read here. Instead of focusing on HRV though having a heart rate sensor to use while running or on a Peloton makes it easier to follow training plans that dictate the intensity of a workout. Keeping in a specific heart rate zone on a Peloton specifically has been the one saving grace to avoid trying to go all out on every ride in order to work up the leader board.

apple watch heart measurement fields

Sleep Tracking

One main area that has never really been a point of daily focus is sleep. The benefits of great sleep are undoubted but for the most part the sensors in the Apple watch do not provide unique enough insights to make a difference. At times using the sleep tracking for a few weeks can set a good baseline for establishing other habits, but once established the need to find another time in the day to charge are too much to over come.

Instead of using the watch as a daily tracker having the sleep schedules setup on a phone and linked to provide reminders via the watch tends to be the best setup for changing behavior. Now we get an alert on the wrist 15 minutes before bedtime with a push to start to wind down and climb in bed. It is easy to dismiss this alert, but that extra push has been enough to keep us from binge watching forgettable shows. We also wrote up a full review of using Apple watch for sleep tracking and compared it to other popular sleep trackers.

apple watch sleep schedule settings

Fitness Trends Using Apple Watch

The combination of having rings and workouts tracked is helpful, but showing a trend line of how your habits compare over time is great. The trends summary of the watch driven fitness data can be a painful reminder of how you have been slacking. We find that at times these average minutes standing or average daily calories is trending down when it was not noticeable on a daily or weekly basis. A trend of running pace time is harder to follow since so many of our runs are done on trails.

Cardio fitness of course is another key that many people find useful. Our review of Apple watch VO2 max accuracy is one of the top articles on this site as many users look to try to improve theirs over time. This metric is much harder to augment than some of the more granular ones, but it is possible to train for a better VO2 max. Other trackers also have a proxy for VO2 max, or Cardio fitness, which gets generalized and referred to by a number of names including the Withings Fitness Level.

apple watch fitness trends


Monitoring daily output from workouts is only half the equation of staying healthy. What you put into your body matters just as much. The apple watch does not do much by way of tracking nutrition, although it does make it easier to log food consumed or calories. We prefer to shift over to dedicated apps, like MyFitnessPal, as it is easier to search for new foods. The summaries of foods though are well displayed within the Apple Health kit. Still without a library of popular foods or the ability to scan something in with your watch the benefits of this tracking are suspect since so much is reliant on the accuracy of tracking calories. This is a hard task to manage though as even MyFitnessPal lacks in calorie accuracy.

nutrition log for apple watch and apple health kit

Body Measurements in Apple Health Kit

Of the rest of body measurements none of them are provided by the Apple watch. Each requires some additional sensor although a body temperature reading may be the most likely to get tacked on via a useful sensor. We prefer to use either a connected scale or connected blood pressure cuff or similar to input all of these metrics but no doubt having a consolidate place to view stats makes it less intimidating to review the data.
body weight logging in apple health kit