There is none. In the winter you should not hibernate and to get some holiday pounds.
In the winter you are in the transition phase.
You don’t stop training, but you have to keep a certain training level and to recover your body & soul.
It’s ok to rest at Christmas and to eat some cookies. We have to train for that in spring.
The more you do in summer, the more important is a structured training phase in the winter. The training is very general, unspecific and reduced. If you train 3-5 times a week, you can keep your endurance and prevent from injuring at the season’s start.
WARNING: In the winter with ice and snow, but also at rain you can get easily injured. Running is dangerous, but biking should be stopped at snow and ice. Change to indoor training. If you get a cold, drop your workouts!
For a proper winter training you need the proper clothing. In spring don’t forget to maintain your bike!
It’s important in the winter to do your planning for the season.