Biking is not only a great way to exercise; I've also found that it's a great way to get around a new city — or to do errands in my own town. Whether for work or for pleasure, when I have limited time to explore a new city, on a bike I can cover a lot of ground quickly. Not only do I get to sightsee, but I get to burn calories and benefit from an awesome leg workout!

You can find a bike rental shop in just about every city, and some now have pay-as-you-go bikes, which means you can conveniently stop and start in different parts of town. You can easily increase the intensity of your ride by finding hills or a park with designated cycling trails. And all the while, you'll be taking in the great outdoors and, with luck, some breathtaking views of the city.