When using the MC Link app there are two main reasons for why activity data won't sync from your device to your Motion Connected account.
1. Do you have the Apple Health App setup and configured to work with your Apple Watch? This App comes pre-installed on your IPhone and must be setup and configured to work with your Apple Watch in order for the MC Link app to access the activity data collected by your watch.
2. Do you see your data in Apple Health but MC Link is showing 0's? If the MC Link app is showing 0's for the activity data displayed on the main page of the app this is caused by MC Link not having access to your Apple Health Data. Within the Apple Health app touch the sources icon on the bottom of the screen and then select MC Link. All of the options on this page need to be turned on in order for MC Link to access the related activity data.