I've started jogging again (can't really call it running, I'm too slow).
The cardio fitness is there, from my kayaking, but my legs just don't have the toughness.
Jog to the nearest train station to get in to work - about 4.4km. Did that once last week. Jog to riverbank carrying kayak and back (post paddle) - 800m each way, twice this weekend. Well, saturday wasn't a jog, it was in a gale, I could hardly stay upright.
Ran in this morning, I'll have to run home tonight, so that will be nearly 9km in the day. I hope my legs forgive me.