Make sure you are wearing Keen on the same hand and in the same orientation as when you trained it.
The first and most important part of Keen is good training. Watch the video below to train Keen well.
Start with only one trained area, then adjust the detection settings to reduce false alarms. Watch the second video below to do this.
Try the "snooze" button if you know Keen will detect during a certain activity, like eating or driving. Press and hold the button to activate snooze, which will last for a default of 7 minutes (this is adjustable in the app).