What do these two activities have to do with each other?
Nothing and everything. (By the way, I wouldn’t recommend doing them at the same time, however, the mind works in strange ways regardless of what the body is doing.)
If you’re stuck for that killer ending to make your reader gasp in amazement, go for a bike ride.
Looking for a great opening line? Go for a cross-country ski. Or a run. Or a paddle in a kayak. Whatever works.
For me, it’s time to be out there, in the woods or on the water, all on my own, simply moving. This combination immerses the mind in a relaxed, creative mood when revelations suddenly flash forth whether you want them to or not.
I have to admit to carrying a notebook, and on occasion, stop to jot down a note or two. But usually, the revelation is enough to be remembered and applied to whatever I’m writing later that night.
So, riding and writing go hand in hand, along with skiing and writing, paddling and writing, and running and writing. Maybe I should buy a pogo stick!