Air travel may be more than just uncomfortable; it could be the cause of a serious medical condition referred to as deep vein thrombosis (DVT). DVT occurs after periods of prolonged immobility when a blood clot—usually formed in the lower leg, but sometimes beginning in the thigh or pelvis—blocks a major vein. Typically, such a clot dissolves once a traveler reaches his or her destination and walks around. But if a clot builds up, there is a risk that it may detach itself and lodge inside the person's lungs. Also known as a pulmonary embolism, it can cause chest pain, shortness of breath, and—if it's large enough—sudden death.
DVT is not limited to air travelers; it can affect anyone seated in a confined space for a prolonged period. Also at risk are people who have varicose veins, cancer, or a history of leg clots, and those who've had leg or pelvic surgery or injuries. Others in jeopardy are those who are pregnant, on birth control pills or hormone replacement therapy, or are dehydrated or overweight, according to Peter Alden, a vascular surgeon in Minneapolis. DVT's warnings signs include pain, tenderness, or swelling in the calf or leg, but symptoms often don't appear until the clot is well advanced, if at all.
The good news is that simple movements found in some yoga postures can prevent a clot from forming. Any pose that stretches the calves, hips, and hamstrings can be beneficial by helping keep blood properly circulating in the legs. Here are some suggestions.
Place your left foot on your right thigh and your right foot flat on the floor. Lean forward for a modified forward bend to stretch the hamstrings as well as open the hips and release the back. Switch leg positions and repeat. "Adding a twist to this pose by bracing your left arm onto your left foot and twisting to the right while you bend forward works the spine and other muscles that can spasm from sitting," says Ana Forrest, who founded Forrest Circle Yoga in Santa Monica, California, and travels extensively to teach.
Another great seated movement is Uddiyana Bandha (Upward Abdominal Lock). Exhale completely and hold the breath out, pull your belly toward the spine, and curl your pubic bone toward your navel, squeezing your sitting bones toward each other. Hold for five to 10 seconds and repeat several times. This releases pressure on the hamstrings as well as the sciatic nerve.
Of course, the best way to prevent DVT is to move around as often as possible. If it's OK to get out of your seat, you can usually find room near the back of the plane for poses like Uttanasana (Standing Forward Bend) and Virabhadrasana I (Warrior Pose I)—both of which stretch your legs and help keep DVT from arriving at your destination.