Last time I used a personal HR monitor (not including the grips on a treadmill, which provide typically slow and erratic feedback) was at least 4 or 5 years ago. This was the conventional HR monitor using a chest-strap, and was accurate and instantaneous, but the strap would loosen, get soaked, etc.
Does anyone here have any comments/recommendations on the latest cheap wrist-type HR monitors? Are they accurate during vigorous exercise? For example, here is an inexpensive Chinese knockoff that even has BP and O2 sensing (R u kidding me?!?):