I've been tracking my HR for two years with a Mio Alpha and the Wahoo app because they were the only HR monitors (at that time) that did not smooth out/average numbers; together I could track second-to-second HR all day. The bummer was that the only way to get a graph that I could print out to compare from day-to-day was for my husband to download into Excel and physically build the graph--10 to 15 min. every time. (Yes, I know how lucky I am!) I just switched to a FitBit Charge HR because it's wrist-based and provides the HR graph as well as steps and sleep info. Reading about HRV though, I really want to do this as well. All of the data adds to more validation from others as well as better self care. The chest strap is a drawback, but might be worth it for the info.