Best answer by tfarabaugh
I'm finding my Spark is giving a HR that is significantly lower than actual when I use it downhill skiing. I'm wondering if it could be impacted by cold temperatures? The watch is on my wrist and that is covered by my winter jacket, but it is the only explanation I can think of. Any ideas?
Cold will definitely impact it as your extremities are not getting as much blood flow as the body's priority is to keep the core warm. Even with a jacket they will still be colder and have less blood flow. I am not sure there is a solution per se, as it is not a technical issue, it is simply that your HR at your extremities is lower in the cold and that is where it measures it. you could try a chest strap instead and see if that helps.
I hope this helped answer your question. If so, please mark it as a solution so others can look for it if they have the same question. View original comment