<p class="source">Source - <a href="http://www.usnews.com/" rel="nofollow" target="_blank">US news</a></p><p>Quit the gym. Or rather, if the 40 or 50 bucks you shell out each month for a membership is shrinking your wallet, remember that folks have been exercising since long before the days of ellipticals and spin classes. Many exercises can be done just about anywhere, any time. Squats in the office; push-ups as the pasta cooks; lunges during "Game of Thrones"—there's no need to pay cash for these moves, just cold, hard calories. Below, five fitness experts with a collective six-pack of 30 abs (don't think about the math too hard) dole out their favorite exercises that require no gym, no trainer and barely any equipment.</p><p class="hr"></p>