The 37 HealthKit Activity Types

Apple's Activity group holds 37 type identifiers. Thirty-five of them are quantity types, which carry a number and a unit. Two are category types, which carry an enum value instead. This is the corner of HealthKit most fitness products read first, and it is where the quietest mistakes live. Everything below comes from this site's HealthKit identifier dataset, parsed from Apple's developer documentation on 2026-08-28.

The 35 quantity types split 20 cumulative, 13 discrete, and 2 that state no aggregation style at all. The cumulative twenty are daily totals. stepCount, distanceWalkingRunning, activeEnergyBurned and flightsClimbed all state cumulative, so summing them over a window is right and averaging them describes the device's write cadence rather than the user. The discrete thirteen are readings taken at a moment: cyclingPower, runningSpeed, vo2Max and the rest of the per-sport telemetry. Sum a discrete type and the number grows with how long the watch was worn. Nothing throws either way, which is why the split gets its own page.

Eight unit families appear across the group: count, counts per minute, distance per time, energy, length, power, time, and volume/mass/time. That last one belongs to vo2Max alone, which also carries 323 words of discussion, more than any other identifier here, and is worth reading before you put a number on a screen. Not everything has a unit family. physicalEffort states discrete aggregation and no unit family, and neither category type has one, because a category type carries an enum rather than a measurement.

Four identifiers back the Activity rings. appleExerciseTime (iOS 9.3), appleStandTime (13.0) and appleMoveTime (14.5) are all cumulative amounts of time, and Apple scopes the appleMoveTime abstract to a specified day. appleStandHour is the outlier: a category type from iOS 9.0 whose abstract counts hours in which the user stood and moved for at least a minute, but whose value is HKCategoryValueAppleStandHour.

The group keeps growing, and recently. Nine of the 37 arrived in iOS 18.0, five in 17.0 and five in 16.0, against seven that date to iOS 8.0. Apple has been adding per-sport telemetry release by release. iOS 16.0 brought running form: runningGroundContactTime, runningPower, runningSpeed, runningStrideLength and runningVerticalOscillation, the last measuring pelvis vertical range of motion during a single stride. iOS 17.0 brought cycling: cyclingCadence, cyclingPower, cyclingSpeed and cyclingFunctionalThresholdPower, which Apple defines as the estimated maximum average power sustained over 60 minutes on a bike. iOS 18.0 brought distances for rowing, cross country skiing, skating and paddling, plus a speed for each of those except skating. Availability is per release, so a metric added in 18.0 does not exist on a device that has not been updated.

Wheelchair users have had their own pair since iOS 10.0. pushCount counts pushes performed while using a wheelchair and distanceWheelchair measures distance moved that way, both cumulative. If step count is the only movement metric your app reads, those users register as sedentary.

Four types in the group have Android counterparts we have verified: activeEnergyBurned and basalEnergyBurned both against ActiveCaloriesBurnedRecord and TotalCaloriesBurnedRecord, stepCount against StepsRecord and StepsCadenceRecord, and vo2Max against Vo2MaxRecord. Everything else here is Apple-only until we verify a counterpart, which is a statement about our checking rather than about Android. The cross-platform matrix shows how those four line up, and the reference pages on step counting and calorie tracking cover what each is made of on both platforms.