I went for a long walk today and didn't get any kind of notification of a walk detected or prompt to start an activity. I have Move IQ and Auto Activity Start turned on and the auto start walk setting is set to 5 minutes. I was probably walking for about 40 minutes before I realized I forgot to start an activity and then started it myself. I wasn't holding a dog leash or pushing a stroller or anything else that would interfere with arm movements.