Tips on how to stay fit and keep exercising during winter as i tend to put on weight in winter. thank you?

Cold Weather: If cold weather prevents you from exercising outdoors, then consider indoor activities such as swimming in an indoor pool, indoor sports (basketball, soccer, etc), stationary bicycling, running on a treadmill, or fitness classes such as yoga, step aerobics, or pilates. As always, check with your physician before pursuing any vigorous exercise regimen.