Summarize this article in one sentence.
Many airports have fitness centers and even yoga areas. If your airport has one, use it! You can get in some cardio, give your limbs a good stretch and get your blood flowing before boarding another cramped flight. If there’s no gym in your airport, you can always bring some workout clothes in your carry-on bag and go for a quick jog around the terminals.  If you plan on doing an intense workout, find out if the airport offers shower facilities. Airport Gyms is a useful website where you can search for fitness centers in or around airports in the U.S. and Canada. Visit the site at http://www.airportgyms.com/. Bring your laptop and take advantage of the free wireless internet access, if your airport offers it (most do). You can finally knock out all those emails you’ve been meaning to send, or put the finishing touches on an important presentation that’s coming up. If you’re a student, get started on that paper that’s due next week, or try to get through a few chapters of your assigned reading. Whether you’re traveling for business, pleasure or otherwise, there will be probably be tons of stuff you need to do once you finally arrive. Make a to-list while you’re waiting so you don’t miss a beat! Include errands and other necessary stuff on your list, but don’t forget to block out some time to see the sights and even just to rest. Check with one of your airline’s ticket agents at the layover airport to see if you can switch your flight. You might be able to get an earlier or later flight if there are seats available, at no extra cost. If your schedule is flexible and you really want to explore the area or city you’re in, consider giving up your seat and taking a later flight out. This won’t always be a realistic option, but if you have the opportunity, take it!

Summary:
Work out at the airport gym. Catch up on email, homework or work tasks. Make a to-do list for when you arrive at your destination. Find out if you can bump your flight.