Faulty heart rate?
Bought my Tom Tom Runner 3 cardio watch 1 week ago (heart rate on the wrist). The watch is working nice, but my heart rate feels faulty. I do cardio workouts and the highest my heart rate gets is like 155 Bpm (and it almost feels like I wanna fall over). I asked my friend to wear my watch while he measured his heart rate with his Garmin watch. When his watch showed 120 bpm, mine only showed 100 Bpm on his wrist? Every time my watch indicated +- 20BPM wrong compared to his. Is this normal or do I have a faulty watch?