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During easy runs, my watch’s heart-rate reading seems believable. During short intervals, though, it sometimes jumps well above what I expect and stays there briefly even after I slow down.
For people who train with intervals, how useful is a wrist sensor for judging effort in the moment? I’m curious whether fit, cold weather, or the quick changes in pace can affect wrist heart rate readings, and when a chest strap makes a noticeable difference.
