You can initiate a sport or exercise session using two methods described below.

Via the App method:

Open the App. Click on the ‘Exercise’ menu. Select a desired sport from the top list and click on ‘Start’. The sport will be initiated after a 3 second countdown.
Any sport initiated via the App will be started on the smartwatch synchronously provided the chosen sport option is loaded on the watch.

Via the Watch method:

Sport initiated on the smart watch will not be initiated on the App synchronously, but the corresponding sports record will be saved on the App.
If you initiate such a sport again on the App, you will see two sports records on the App.
For the sport initiated later on the App, only the data obtained from the phone will be displayed.