Many people try and work the xmas lard off by doing something silly like joining a Gym. They then spend a couple of weeks humiliating themselves in the presence of lots of sweaty muscle Marys and then give up.
Me, I’ve done gone and got meeself I mega bike light. It’s a Hope Vision Epic and you it strap it to your hat (or bike) and go charging about in the dark. I say dark, but the Hope Vision, although tiny, illuminates the road like a car light. Owls, deer and all manner of wildlife flee as you swoosh through the woods.
The only down side of course is that if you do decide to wear it on your hat you can look at bit of tit.