Let’s face it — it’s tough to find the motivation to exercise outside these days. During the work week, sometimes both legs of our daily commutes are completed in utter darkness. And while weekend sunshine is appreciated, it doesn’t do much to warm up our wintry surroundings. But before you throw in the towel and restrict yourself to the crowded, stuffy gym for the next few months, it may be worth giving the idea of a winter workout a second thought.