My new Versa 4 gives sensible estimates of cardio load, from 50 to 200 or more, for outdoor activities such as running, hiking and cycling. These loads are predictable from the times spent in peak, vigorous and moderate heart rate zones, as I;d expect. But for spinning (stationary bike), it gives cardio loads of 1 to 5, for times in heart rate zones that would yield cardio loads of 50 to 100 in outdoor activities. I tried using my stationary bike, setting the exercise to bike instead of spinning, and turning off GPS, but it still yields the same ridiculously low loads. It appears the cardio load algorithm is useless for indoor activities, or at least for spinning. The heart rate sensor seems to be accurate and reliable, provided the band is very tight. But in outdoor activities, the stand-alone GPS produces typical errors of around 10 % in distance and pace. Given the GPS and cardio load failures, my Versa 4 is effectively unfit for both indoor and outdoor activities.
