This is not necessarily the same issue as you're talking about, but I feel like in the winter, doing your workouts outdoors in the daytime can be a good thing.
Some people (including me) find that they stay indoors most of the time in the winter. Doing your workout outside gets you out there, which gives you not only sunlight (speaking of Vitamin D) but also a change of scenery that can cut down on cabin fever.
With the proper gear, the cold is tolerable (except maybe in extreme climates). And, especially if the exercise is vigorous, it's more tolerable being outdoors in the cold than it would be if you just went stood or sat around outside.
Some people (including me) find that they stay indoors most of the time in the winter. Doing your workout outside gets you out there, which gives you not only sunlight (speaking of Vitamin D) but also a change of scenery that can cut down on cabin fever.
With the proper gear, the cold is tolerable (except maybe in extreme climates). And, especially if the exercise is vigorous, it's more tolerable being outdoors in the cold than it would be if you just went stood or sat around outside.