“I would advise against anything really constricting,” says Fischbach. “You want to get the most comfortable you can be to avoid cramping, swelling, and anything that can affect you later.” Allowing for healthy blood circulation is especially important to avoid deep vein thrombosis (DVT), which occurs when a blood clot forms in a vein, usually in the legs. “It’s very important to be able to move around a bit in your seat—very difficult, I know—and keep your blood flowing,” Fischbach explains. “If you are tall, travel a lot, or are on a long flight, this is extremely important because you face the risk of developing DVT.” More innocuously, swelling in the stomach can also occur, causing discomfort, especially if you’re in restrictive clothes. “Bloating is a major issue, even for flight attendants, so wear something comfortable around your waist like elastic,” suggests Fischbach. “As cute as they may be, leather pants probably aren’t the best.”