» Prevent swelling. Blood collects in the feet and they begin swelling within one hour of taking a seat. Wear roomy slip-ons, which also smooth security screenings. If you’re at risk for deep vein thrombosis (opposite), ask your doctor about prescription over-the-calf compression socks or sport a pair like 2XU’s Compression Socks for Recovery ($50; 2xu.com), which increase circulation and may reduce muscle fatigue and blood clot risk.
» Eat and drink right. Carry-on a combo of protein and complex carbohydrates like a peanut butter and whole-grain bread sandwich, which is healthy and will hold up without refrigeration for a 12-plus-hour flight. Drink a lot of water: Breathing dry air inside the cabin will dehydrate mucus membranes and cause discomfort within a few hours of takeoff.
» Sleep soundly. Take precautions against cramped airline seats. Consider taking an over-the-counter sleeping pill, or a 0.5 to 5 milligram dose of the natural sleep aid melatonin, on flights longer than eight hours. Pack earplugs and an eye mask.
» Move around. The muscles and ligaments that maintain your back’s natural curve relax and collapse when you sit for long hours with poor posture. If your travel is longer than four hours, get up every hour and walk the aisles to stimulate the flow of blood, oxygen, and nutrients to your muscles, preventing soreness. When sitting, keep your neck and shoulders straight, and use a small pillow to support your lower back.
» Stretch. Prevent pre-hike stiffness, relieve back pain, and aid circulation with these sit-down stretches recommended by yoga instructor Olivia Hsu-Richards.
Spine Twist: First, spend 30 seconds deepening your breathing and concentrating on filling both lungs evenly. Then inhale deeply while lengthening your spine, stretching the crown of your head toward the ceiling, and keeping your eyes forward. Twist your torso to the right, maintain your head’s alignment with your spine, and turn your gaze over your right shoulder. Grab an armrest and pull gently to deepen the stretch and hold for five full breaths. Return to center, and repeat the stretch on your left side.
Hip Opener: Shift forward in your seat and press your left foot firmly into the floor. Lift your right knee toward your chest and hold for 30 seconds. Cross your right ankle over your left knee and tilt your right knee to the side, pressing on your leg with your hand to deepen the stretch. Return both feet to the floor and repeat on the opposite side. Do 5 to 10 sets.