How do I use Quick Start-up?

"Press the SEL button on the watch face to quickly open an app. The Workout app is opened by default. You can go to Settings > Preferences and tap the Shortcut buttons to set other application you frequently use.

You can also go to Settings > Preferences > Shortcut buttons> Long press SEL Button/Long press UP Button/Long press DOWN Buttonto change the app used for quick start-up."