Exercise mode - Fitbit Sense

[MrMattt]

When I use the 'exercise' app on my Fitbit Sense it disables all other screens on the watch. I can't see my clock, and more importantly I can't access the stop watch app. 

Can someone explain how to do this? 

Also, is there an option that I can enable so the watch will detect my lower heart rate and notify that I may have forgot to turn off exercise mode? 

For a fitness watch I find the exercise features to be quite odd. Hoping it's just me and my lack of understanding. 

[JohnnyRow]

After you select your exercise type, not the small arrow at bottom of watch screen and swipe up from there.  You will see many more options including what you want to display on 3 screen lines.  Time of day is one of those options.