Help please with HRM, max heart rate

crafty30

I recently bought a K920D Pulse Sonic HRM Watch and have been using it for my past few workouts. It seems great apart from one thing..I set my max heart rate at 186 as this is what the calculation says it should…so I set it so it beeped if it went above that. Well My heart rate seems to vary from 125-165 in my workouts, sometimes more if Im going for it and it never beeped to say I had gone over but at the end when it says my max heart rate and my average, my max said 194?! Surely this isn’t right? The only think I can think of is when I first used it I went on the treadmill and was doing some sprints at a fast speed and I know I looked at one point and it had gone up to 194 so I slowed right down. So could this be that it is taking all my workouts in to consideration? Do I need to do something to re-set it every time I workout? Any help appreciated as I would like to get an accurate reading for each individual workout if this is possible?

Thanks
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