Originally Posted by TCR Rider

I started running around the age of 30, adult onset athlete. I discovered that I really enjoyed it and became a 50 mile a week runner for the better part of 25 years - I am now 63. I ran many many races and 9 marathons including Boston. I really only rode a bike when I was recovering from a running injury or for fun.
I had an achillies injury that required surgery and a tendon transfer. That was when I started making the transition to the bike. I purchased a carbon frame road bike and really started to enjoy riding. The kicker was when I had a cycling accident as I recovered from the achillies surgery and fractured a hip. The break was in a place where it required a hip replacement. That was the end of my running days. The impact from running would really shorten the life of the hip so cycling was the obvious low impact alternative.
One of the most enjoyable things about cycling as opposed to running is finishing a hard ride and feeling tired and not trashed. When I was marathon training it was not uncommon to take an ice bath after a hard 20 miler. I do miss the simplicity of running but I have made peace with it and don't have to deal with all those niggling injuries. I currently ride 6 days a week between 180 and 200 miles. I throw in a couple of walks and kettlebell circuits with some yoga to round things out.
God bless you guys that can still run but it's the bike for me and I'm OK with that