I think I have heard every excuse in the book when it comes to exercising, but I think that "I can't exercise in Winter, it's too cold" is probably the worst one I have heard. There is no such thing as a season throughout the year where you cannot exercise, not even Summer. I have made up a guide on how to exercise during Winter, for the people who are afraid it's too cold.
Move your equipment indoors, if you have an exercise bike collecting dust in the garage, clean it up and lace it somewhere inside or in your bedroom. Moving your equipment indoors will still let you stay warm and free from the cold outside.
Go walking, even if it's a cold day you will certainly get warmed up while you walk. I have done this plenty of times, walking in Winter is actually one of my favourite things to do.
Wear proper warm exercise clothes like tracksuit pants and a plain jumper or jacket. I used to make the mistake of wearing a t-shirt and shorts when I exercised in Winter because I thought I would get hot. If you start getting hot then just wear a long sleeve shirt.
Go swimming in a heated pool, it'll be nice and warm and the only cold you'll be feeling is the walk to and from the car.
Don't go too hard to the point where you're sweating and getting extremely hot. Try and do as much resistance and light cardio exercises throughout the cold season.
Don't exercise with the heater on, I also used to make this mistake and would keep a mini heater on while I used the exercise bike. Exercising isn't meant to be cool and comfortable, switch the heater off and pedal faster to get the blood circulating faster around your body.
Exercising in Winter does not need to be a struggle, you just need the right advice to go about it.