We recommend keeping your WHOOP mobile app running at all times in the background for the following reasons:
- This allow the data from the Strap to continuously sync with the WHOOP app, and ensures your scores and recommendations remain up-to-date.
- If you close the app (on your phone), WHOOP will need to re-sync all the data from your Strap the next time you open the app; which can take some time as the data catches up. See: Missing Data
Additional NOTE: While you can wear your WHOOP Strap for sleep and recovery only, we recommend wearing your Strap as much as possible to get the most accurate and consistent analysis of your physiological data.