More and more people care about their health nowadays. A lot of people try to make sure that they eat the right foods and maintain an active lifestyle. A considerable part of this group uses fitness apps and trackers, such as the Apple Watch, to measure and record their activities. All of this activity data is logged using Apple's HealthKit frameworks.

App developers can integrate HealthKit in their apps to track and record workouts, activities, and many other metrics that are meaningful for monitoring personal health. Because more and more people care about this data, Apple aims to continuously improve the HealthKit framework so that app developers can focus on building great apps, rather than figuring out how to integrate their data with iOS.

This chapter covers the following topics:

Understanding HealthKit
Implementing a workout app
Integrating with iOS

By the end of this chapter, you will know how to build an application that tracks user activity in HealthKit. You will also know how to extract data from HealthKit so you can provide more accurate metrics for the workouts you log to HealthKit.