I’m an 82 yo roadie, wearing a Fitbit Charge 4 to monitor my heart rate (while riding) and sleep behavior. I had previously worn a Fitbit Charge 3 for 3 years and would have it still, except that I lost it after taking it off at a rest stop. I replaced it with my (current) Charge 4. I ride 3 or 4 times a week, usually 15 – 30 mile routes that I repeat over and over, recording bike computer and FB data for each ride.
I’m especially interested in my heart rate, and study the graphical plots Fitbit shows on my phone. I’m able to associate the various peaks and valleys in the plots with the hills, traffic light stops, etc. on each leg of my rides (out and back). The FB immediately recognizes whether I’m running or on my bike, and also recognizes when I make a rest stop – therefore stops recording heart rate until I resume my ride. The result is 2 separate plots displaying data only for my actual riding, omitting the time spent at my rest stop/turnaround.
The data I’ve collected is very consistent, heart rate matches my perceived level of effort. Sometimes I ride one of my routes harder than usual, or the wind is really high, or I do a slow and easy recovery ride. The resulting FB heart rate plots look exactly as I expect. I haven’t worn a separate heart rate monitor, so I have no other heart data to allow specific comparison. I’d enjoy hearing how someone who has worn both wrist and chest heart monitors found their level of agreement.