Use short bursts of exercise to save on heating

In cold weather, many people feel guilty for running the heater constantly. This could be for environmental or financial reasons, given the recent increase in fuel costs in plenty of places. One way of saving money and energy is to try short bursts of exercise. YouTube and http://www.exercisetv.tv/ are full of options. And you can also just do your own thing: jump, skip, dance, run or lift heavy items in the comfort of your home for 5 or 10 minutes at a time. Not only will you get fitter, but you'll be able to forestall the march to the thermostat. Of course, this isn't practical for a lot (or most) of the time, but there are loads of benefits to replacing fuel heating with internal body heating at least some of the time.

Effort involved: well, effort is kind of the point with this one, since you want to warm yourself up through physical activity. But it's possible to get very warm and well-exercised in a short amount of time.

Image from: http://www.squidoo.com/shake-weight-is-funny