Apple Health is one of the most used apps for active individuals and athletes, but the vast amount of data available can be overwhelming. Knowing which metrics to focus on can help cyclists understand and document their stats, customize training sessions, and improve athleticism both on and off the bike.

What is Apple Health?

Apple Health is an iPhone app that automatically tracks distance, steps, and other metrics by using the phone’s built-in accelerometer. It syncs up with Apple Watch to track fitness levels and provide helpful metrics for athletes and non-athletes alike.

When you wear the watch during a ride, you can keep track of important metrics (such as distance, speed, heart rate, heart rate variability, elevation gain, and calories burned), as well as sleep and environmental sound levels. You also have the ability to integrate data with other popular fitness products and apps such as Strava, Peloton, and Garmin, allowing for even more data analysis and sharing across platforms. 

Apple Watch is a great tool for cyclists because it allows you to track rides, set goals, and see metrics (both on and off the bike). To track a ride, simply select Outdoor Cycle from the Workout menu on the app (or select Indoor Cycle if you are on a stationary bike). From there you can select a goal based on distance, time, or calories, or choose an open goal. You can also measure elevation, heart rate, and speed with the Apple Watch. 

This tool is also beneficial for when you’re not training, you can collect data on heart rate variability (HRV), sleep, and resting heart rate. These metrics will not only help you assess performance, but it will also aid in recovery and your readiness to train. 

Heart rate

Apple Watch monitors your heart rate continuously throughout a workout, and will continue to measure for three minutes after the end of a workout to determine a recovery rate. It uses green LED lights paired with light-sensitive photodiodes to detect the amount of blood flowing through your wrist [

10

]. When your heart beats, the blood flow in your wrist is greater, and less in-between beats. By flashing its LED lights hundreds of times per second, Apple Watch can calculate your heart rate by the number of beats per minute [

10

]. However, heart rate is more than just beats per minute. Two metrics--resting heart rate and 

heart rate variability

--are determined using heart rate measurements, which are both important for performance levels.

Resting heart rate

Resting heart rate (RHR) is one of the most basic measures of health and fitness. Having a lower resting heart rate is associated with better cardiovascular health outcomes and an extended life  expectancy [

1

]. Cyclists and other athletes tend to have a lower RHR than the general population because endurance training makes the heart more efficient at pumping blood [

1

]. In trained people, the heart needs fewer beats per minute to transport blood throughout the body, resulting in a lower heart rate. 

Your resting heart rate can also determine recovery levels and alert you to potential overtraining. If you notice a resting heart rate that is higher than your average, you may not be fully recovered from a hard workout or ride. An elevated RHR may signal you to take a rest day, while a lower RHR may indicate increased readiness to perform at your best [

2

]. 

Heart rate variability

Though less popular than resting heart rate, heart rate variability (HRV) is an important measure of health and fitness. HRV is defined as a measure of variation in time between heart beats and comes from simultaneous influences from the parasympathetic and sympathetic nervous systems. Your sympathetic nervous system (also known as “fight or flight”) causes the heart rate to increase, while your parasympathetic nervous system (also known as “rest and digest”) causes your heart to beat slower. These competing systems result in heart rate variability [

3

].

Like resting heart rate, HRV can be used to assess training levels and gauge recovery. A higher HRV can be used as an indicator to train more or give your maximum effort [

4

]. Conversely, a dip in HRV suggests that you may need more time to recover or take an easier ride. 

HRV is highly individualized and dependent on several factors, including training volume and intensity, nutrition, alcohol intake, sleep, stress, age, gender, and genetics [

5

]. HRV is highly individual and should be compared to your own statistics over time rather than standard results.     

VO2 max

VO2 max is defined as the maximum amount of oxygen utilized by the body during periods of exercise [

6

]. Higher VO2 max levels are associated with lower risk of cardiovascular disease and all-cause mortality and tend to be positively influenced by high intensity exercise, such as cycling [

6

,

7

]. Other factors that influence VO2 max are training intensity, altitude, age, and biological sex.

VO2 max values can be used to assess your progress during a training cycle. The best way to improve your VO2 max is by incorporating higher intensity workouts and alternating between continuous and interval training. Apple Watch uses watch sensors like the heart rate monitor and accelerometer to calculate VO2 max [

10

].

Exercise minutes

One of the more basic metrics you can get from Apple Health is exercise minutes. Every minute of movement that is equal to or exceeds the intensity of a brisk walk will contribute towards your exercise minutes and this is a great way to keep a log of your total cycling and training time. 

For adults, physical activity recommendations are at least 150-300 minutes per week of moderate intensity or 75-150 minutes per week of vigorous-intensity aerobic physical activity, plus muscle-strengthening exercises at least twice a week [

8

]. Many athletes, especially endurance athletes like cyclists, significantly exceed these recommendations, but keeping track of weekly exercise minutes can be used to quantify training output and progression. Tracking exercise minutes also helps prevent overtraining, especially when preparing for longer races and executing long rides. 

Blood oxygen 

The latest Apple Watch model (Series 6) is equipped with a blood oxygen sensor and app, providing you with data on oxygen saturation. This metric represents the percentage of oxygen bound to hemoglobin in your blood. It works by emitting red and green LED and infrared light onto your wrist and measuring the light reflected back. This can be used to determine the color of your blood and give an accurate reading: the brighter the blood, the more oxygen available, and conversely, the darker the blood, the less oxygen available [

11

]. 

Understanding your blood oxygen levels is especially helpful for cyclists training at altitude, as the air at higher elevation has a lower concentration of oxygen than at sea level, resulting in less oxygen in your bloodstream. Moreover, a drop in blood oxygen can indicate worsening asthma or anemia. Checking your blood oxygen levels can help prevent overtraining, and help track your progress in acclimating to altitude [

9

]. 

Sleep tracking

Sleep is another useful Apple Health metric for cyclists, as proper rest is crucial for performance and recovery. Sleep features available in Apple Health include monitoring sleep trends, setting bedtime hours, and updating your sleep goals. Moreover, Apple Health integrates with Apple Watch, Oura and other sleep trackers for cyclists who want more granular information about sleep quantity and quality to improve performance and assess readiness to train. 

Summary

For cyclists looking to monitor their progress, develop a training plan, log rides, and prevent overtraining, Apple Health provides a wide variety of helpful metrics. Understanding key metrics such as resting heart rate, heart rate variability, VO2 max, exercise minutes, and blood oxygen, can help determine your overall fitness level and inform future training plans. While the data from Apple Health is not always 100% accurate, the app provides numbers and trends that can be used to assess readiness to train as well as training progress. Learning more about your cardiovascular and overall health is key to becoming a stronger, faster, healthier cyclist.

Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose, or replace personalized medical care.