The menu on the 735 (IMHO) sucks
Click on the top-right button and it puts you in the last activity profile (e.g. run). While in this "pseudo" activity mode, it starts looking for sensors and GPS (if the latest activity is outdoors activity) - I guess Garmin did this to save time when you actually go into the activity.
From there you can go up to choose another activity (e.g. swim) or down for all the other stuff (settings, history, training, etc.).
This sucks since
a. Totally not intuitive. To change activity type you need to first click up, then start scrolling to look for it - and if you went to the other menu you have to go back and start all over.
b. Even if you want to go to change some setting or look for history, it will beep and start looking for gps as soon as you get into the menu - just annoying
If anyone at Garmin is reading this, please consider simplifying the interface by splitting these two menus (similar to the Fenix3) or at least eliminate this annoying activity mode