Wrap up, I like mountain biking when it’s been dry for a bit, cold frosty mornings are lovely.
Funnily enough I feel safer on the road bike in the dark in the mornings, a couple of big flashing lights on the back and I’ve had no problems (touch wood) just need to be wary when the sun is low and the road is wet.
Running is crap, but is better than nothing.
The Gym is soul destroying but warm.
Otherwise, migrate south.