If you are trying to count calories, they are ALL bullshit, ALL of them. I have used them ALL. From Polars with the heart rate monitor strap, fit bit which it total junk, they said the apple watch was the best you can get, mine has me burning 7,000 a day... YEAH RIGHT. I may burn 3,000 on a good day, but not 7. Then I eat about 1600 calories a day and I am losing zero pounds....It may count step, flights of stairs, heart rate etc... but the calorie counter is bullshit.