1. Data update is not timely: You may have updated the health data of iPhone, but these data are not synchronized to iCloud or Health app. In this case, you can try opening the settings-> Health->; ICloud synchronization to ensure data synchronization to iCloud.
2. Data incompatibility: If you are using an old version of iOS or Health app, it may lead to data incompatibility. Try to upgrade to the latest version of iOS or Health app, and make sure that your device is synchronized with the latest version of data.
3. Network problem: If the network connection is unstable or the delay is high, the data may not be updated in time. In this case, you can try to disconnect and reconnect the network, or wait for the network connection to return to normal before trying to update the data.
4. Privacy settings: You may have restricted the use of health data in your settings. Open settings-> Privacy->; Sports and fitness-> Stay healthy and make sure that the "Exercise and Fitness" option is turned on.
If none of the above methods work, you may need to contact Apple Customer Service or iTunes Support for further support and assistance.