I’ve recently augmented my runs with some non-traditional cross-training.
Throughout January and February I was busy with rehearsals for a musical put on by the local community theater group. Singing, dancing, etc. was great fun, but once we started rehearsing with the orchestra I started feeling nostalgic for the days when I would have been one of their number instead of a member of the ensemble.
So I picked up my clarinet and started playing again. And I really think it’s a form of cross-training. It does nothing for my legs, of course, but the breath control needed can only improve my cardiovascular fitness. It’s a great, relaxing way to help improve my running without sacrificing my rest days.