Each morning, RISE checks Apple Health for the previous night’s sleep. If your tracker has sent data to Apple Health, RISE will use it. When you don’t use your tracker you’re still covered with our automatic phone motion-based sleep detection.

RISE uses your awake stage to help determine your total sleep time and throws out the rest. REM, light sleep, deep sleep don't have an impact on how you're going to feel or perform the next day. Your brain naturally regulates and calibrates sleep stages each night. It is very good at knowing how much of each step your body needs. You can't optimize that process. What you can do is ensure you're getting enough sleep so that your brain has ample time to get its work done. You can also avoid substances that affect your sleep like alcohol, caffeine, and nicotine close to sleep.