The info on the website says the middle activity ring counts 30 mins a day off exercise at our above a brisk walk - but does anyone know how it determines this? I can't find anything anywhere saying what criteria it uses. Obviously if you do a workout it's easy but it also says it will pick up exercise through your day. I had a pretty active day in the park yesterday clocking up 16k steps and 800 calories but only just met my 30 mins. I was walking for hours at a time, much of it briskly but sometimes got no credit at all when I checked. This makes me wonder if it's using a minimum heart rate threshold, but as it only read every 10 mins if you're not doing a workout you could have a raised heart rate for 10 mins before it registers. Anyone have any idea?