I was going to take a nice bike ride today - only to find out my poor new tire had a blowout inside the shed. Hopefully just a pinch flat, but I didn't have time to change it and still get in much of a ride.
Decided to do some work on foot instead. Warmed up one mile. Ran half mile hard, walk one tenth, repeat for four work intervals. Finish it off with a couple shorter jogging intervals to warm down.
I hope that helps since I have nothing in the way of long runs to count toward my Steelhead half Ironman preparation. Going to have to just wing it on "muscle memory" and a few short runs.