Apple Watch users can now view their cardio fitness levels in the Health app on iPhone, and receive a notification if it falls within the low range.
According to the company, with iOS 14.3 and watchOS 7.2 software updates, people can measure low cardio fitness for dramatic long-term health benefits.
"Using its advanced sensors, Apple Watch now brings estimation of low cardio fitness levels from clinics directly to a user's wrist, so people have more insight into how they can improve their long-term health through daily activity," Jeff Williams, Apple's chief operating officer, said in a statement late on Monday.
With watchOS 7, Apple Watch uses multiple sensors, including the optical heart sensor, GPS and the accelerometer to estimate lower levels too.
watchOS 7 also allows Apple Watch to take cardio fitness measurements as users walk throughout the day, whether or not they are tracking a workout.
"With this innovation, Apple Watch is better able to measure VO2 max for users with low cardio fitness, who may not complete high-intensity workouts," the company said.
Cardiorespiratory fitness, as measured by VO2 max, is the maximum amount of oxygen the body can use during exercise, and it can be increased through physical activity.
Apple Watch already estimates average and higher levels of VO2 max during vigorous outdoor walks, runs, or hikes, which many runners and other athletes monitor to improve performance.
Research suggests that cardio fitness is a stronger predictor of mortality risk than common risk factors like smoking, diabetes, and hypertension.
"American Heart Association science associates low cardiorespiratory fitness levels with a higher risk of cardiovascular disease and all-cause mortality," said Nancy Brown, American Heart Association CEO.
Apple Watch users can visit the Health app on iPhone to set up the Cardio Fitness Levels feature and turn on cardio fitness notifications, the company said.
Apple Watch also has several other health features like ECG, Fall Detection and more.