Oura monitors the balance between your physical activity and your recovery during sleep, and uses that information to give you an adjusted personal target for daily activity. The activity target is based on your age, sex and daily readiness.
When your readiness score is above 85%, your target will be set higher than your average. Days like this are typically optimal for taking your training to the next level and developing your physical performance.
How is distance calculated?
The distance (mi/km) representing your Activity target is not the real distance traveled, but the equivalent walking distance of all your daily activity. It's a calorie burn target translated to a walking distance, meaning that it shows how far you could walk to burn the same amount of net calories.
Higher intensity activities like jogging take you closer to your target quicker than low intensity activities such as casual walking, even if the real distance traveled would be the same.