I have already shared with you,
@Anonymous1502 how you determine your resting heart rate. When you checked it this morning before getting up, what was it?
This distribution is from Fitbit data (so most of the subjects are presumably interested and indulge in exercise, and see below my text on general (US) population stats):
https://www.businesswire.com/news/home/20180214005548/en/Fitbit’s-100-Billion-Hours-of-Resting-Heart-Rate User-Data Reveals-Resting-Heart-Rate-Decreases-After-Age-40
During the day just walking around my HR is 30 beats above resting (well I've just taken it to check). Only a 4 hour ride today though, and back for the England v Wales rugby (doubt my HR rose while watching that rather turgid match). I rode the first half with a young lady who is slower than me, but very determined. I know that if I keep below 120bpm then she can hold my wheel on the flat/false flat, so I keep a beady eye on the display and rein back if necessary.
So if your resting HR (HR
rest)is 72 (which is 'average') then 106 is perfectly reasonable.
This study offers you more detail:
https://www.cdc.gov/nchs/data/nhsr/nhsr041.pdf
Results (I have selected and precised for the OP - female assumed aged 19-21):
HR
rest mean in adulthood plateaus at 72bpm. There is a gender difference: adult females under 20 have a mean HR
rest of 90bpm, . . . females over 20 mean HR
rest of 74bpm.
3 hours after cycling for 3 hours my heart rate is still very high @106. Is my heart rate high because of the cycling?
so I could get some answers
1) You have not established that 106 is 'high' for you.
2) After 3 hours cycling your HR will be a little elevated for some time - this is entirely normal and shows you worked hard and enjoyed your ride.
3) What's the question? If it's "Is my heart rate highER because of the cycling?" then 'yes'. What actions will you take having received that answer? (Suggestion: None.)
4) Go for another ride tomorrow. Wear an HR monitor for extra data.