An activity tracker of some kind is an absolutely essential tool for any age reversalist. Even though I don’t think calories are all that important, you can’t just wildly guess at how many calories you are burning. Or how far you ran or cycled, and at what speed or pace. It’s all so important when one is attempting ito determine what, precisely, is workingi (or not working)! Remember guiding principle number 4 which states, “Everything matters; what one eats, when one eats it, type of exercise, duration of exercise, intensity of exercise, state of mind, what one thinks, and how one thinks. Everything! The seemingly smallest details matter. Changing them can have profound effects, even if we cannot understand why. Consequently, I will document as much as is reasonably possible.” Having the data an activity tracker provides has enabled me to quickly make adjustments. Of equal importance is its ability to help discover correlations. Without an activity tracker, I would never have known that alcohol raises my resting heart rate and heart rate variability.
FitBit Charge II
I use a Fitbit Charge II, which, for the most part, does everything I need it to. It tracks my steps, resting heart rate, current heart rate, my sleep, and many other important metrics.