Cycling is something I ought to do more of.
I had a bad fall a few years ago. Just a simple slip, but broke my arm landing. More damaging was the fact that my knees are pretty well gone. I had to do a lot of physiotherapy before being able to walk comfortably, and still suffer a lot of pain and stiffness.
So, in order to get some decent exercise, I ought to cycle more. The point about cycling is that I don't put so much stress on the knees - they aren't having to support me, they aren't getting any impacts, and they're not in danger of being twisted. Which is all good.
The first time on the bike this year really hurt. The worrying thing was that it was only about a mile. But more practice and it's getting easier.
But on Wednesday I had the day off and we took the girls to school by bike, and cyycled over to the park and ride. About 10 miles in the day, and only slightly sore knees afterwards.
I reckon that with a bit more work I could feasibly cycle to work - it's about 10 miles in a straight line, but 15 by a more reasonable route avoiding the worst roads (and the odd hill). Good exercise for me; good for the environment; saves the expense of driving to work; saves the hassle of finding somewhere to park. All good things, but it's going to be a while before I'm fit enough.