Its an interesting subject. Mine is 43-48 bpm resting. I am not a sportsman, but I do at least 1 hour each day, and on occasions I can push myself to 12 hours fast paced mountain hike.
perhaps some people have it like this as part of physical body energy/personality. I am characterized by high intensity & concentration when needed....

diagnosed with AS April 2018, starting with cervical pain/stiffness; Aug 2018 enthesitis/bursitis left Achilles
diagnosed with AAU Nov 2017 (7 flares so far)
Eosinophilic Gastritis
Sulfasalazine 3g 08.2018-05.2019 (worked for AAU & peripheral)
Supplements:C/D, omega 3/Probiotic/ Mediterranean NSD/curcumin
Predonisone in case of another AAU flare