I think if you ran a little bit you could acclimate quickly. For a couple years I did nothing but squats, bike (not as much as you), and skate. Then I got this nagging groin tightness I couldn't shake. I remembered something i heard about nhl trainers not liking players riding bikes in the off season. So I just started running a little bit, like a half mile. After the first time everything hurt.
A couple weeks of it and I was fine. half mile, maybe a mile a couple times a week. It also mostly got rid of my groin problem. I think you need that double pendulum motion every now and then so your legs develop/stretch as evolution dictated. I suspect excessive biking and non walking/running leg exercises develops some muscles excessively and neglects others and doesn't adequately stretch tendons/ligaments
I had similar problems and my physical therapist and trainers figured out I needed to do more stretching pre and post ride and do an actual warm up before going balls to the wall. Groin tightness from cycling is also usually an indicator of a really poor bike fit and, in my experience, goes away after a saddle adjustments and proper stretching. YMMV.
Just got cleared by my doctors to start the next chapter in my exercising life - endurance riding. A1c is 5.2, BP is perfectly normal, cholesterol is perfect, kidneys are functioning properly, and, minus lugging an extra 140lbs around, I'm perfectly healthy and ready to push my body to the breaking point. First enduro ride is 360 miles over three days from MPLS to Duluth and back on the fat bike.