Thanks for your question radox. Unfortunately it is not possible to do so. The Watch (while connected to Bluetooth headphones) is to only play audio, and not play haptics if the app is backgrounded. It is also expected for the Watch to only play haptics when the app is foreground running and connected to Bluetooth headphones. When headphones are connected, we'd like to notify the user in one way, either haptic or audio (depending on the state of the app), to avoid redundant notifications during the HKWorkoutSession.