Select "HIIT" when performing a training cycle consisting of high-intensity training and short rest or recovery. For example, you can jump rope for 45 seconds, rest for 30 seconds, and then repeat this cycle.

Some irregular movements during HIIT may make it impossible to measure the heart rate. When heart rate information is not available, the device will still use the built-in accelerometer to track your fat burning information. If you can't get heart rate data continuously during HIIT sports training, you can connect AppleWatch with Bluetooth chest strap.

When you can't find a matching physical training type, please select "Other". In all physical training, the heart rate sensor and the motion sensor will work together to provide you with accurate motion scores. When using any of the physical training types provided in the "Other" or "Increase Physical Training" sections, if these sensor readings are not available, you will get an exercise score equivalent to a brisk walk.