Whether you're planning a getaway, taking frequent business trips or visiting family for the holidays, traveling — especially over long distances — can put considerable pressure on your body.
In fact, long-distance flights that are generally more than four hours can put some travelers at serious risk for developing deep vein thrombosis (DVT), commonly known as blood clots, Ron Drainer, PT, physical therapist and therapy supervisor at SSM Rehabilitation Health Network, tells LIVESTRONG.com.
And the longer the flight, the higher the risk of developing a clot. According to the American Society of Hematology, flights lasting 8 to 10 hours or longer pose the greatest risk.
"Traveling for long durations can definitely cause blood clots, and not just in planes, but also car or train rides," Drainer says. "While sitting for a long period, your circulation slows down, which contributes to the formation of blood clots."
If you experience any swelling greater than 3 centimeters in one lower limb compared to the other, generalized swelling of one leg, localized tenderness or pitting edema (swelling where an indentation is preserved when pressure is applied and then removed), seek immediate medication attention.
It doesn't help that most airplanes have limited leg room, cramped and confined seating space and less-than-ideal back support. These traveling conditions can have other negative effects on your body, too, according to Carina Sobel, PT, DPT, a physical therapist at International Multiple Sclerosis Management Practice.
During prolonged periods of sitting, certain muscle groups, such as the hip flexors and hamstrings, remain in a shortened position, resulting in muscle tightness, Sobel says.
"When we contract our muscles, they act like pumps that help to circulate blood and move it against gravity in order to return to the heart," Sobel explains. "However, if we are sitting still and not contracting our muscles very much, that pump system becomes a less effective and blood may begin to pool."
These health effects, including the development of blood clots, "can happen to anyone," Drainer says. But the good news is that there are several exercises and stretches you can incorporate into your in-flight routine to help prevent them.
Risk Factors for In-Flight Blood Clots
Air pressure changes during a plane flight, which, according to Sobel, can affect how much oxygen is getting into your bloodstream. When there is decreased oxygenation of blood in the body, it can trigger coagulation or the formation of a blood clot.
"Each vessel in the vascular system can be compared to a hose," Sobel says. "If a person is sitting for a long period of time, kinks may form in the hose or vessel, and this makes it easier for a clot, or thrombus, to form."
Several other factors could put someone at a higher risk of developing a travel-related blood clot, Sobel says. These are some of them, according to the CDC:
- Active cancer or recent cancer treatment
- Bedridden for more than three days
- Surgery or injury within the last three months
- Previously had a blood clot
- Heart failure and hypertension
- Pregnant or have recently given birth
- Take an oral contraceptive
- Undergoing hormone replacement therapy
Additional contributing factors that can increase your risk for blood clots include age (especially if you're over 65), obesity, smoking, dehydration or a family history of blood clots, Drainer says.
6 Exercises to Try
The ideal exercise to help prevent blood clots is standing up and walking, Sobel says. But space is a limiting factor, especially when traveling on a plane — sometimes it's not possible to get to the aisle.
Luckily, several beneficial movements can be done from your plane seat and the aisle, if that's an option on your flight.
All of these exercises and stretches increase the circulation of your lower extremities (including the ankles, calf, hamstrings and quads) and minimize the risk of blood clots, Drainer says.
"Each exercise should be repeated every 1 to 3 hours depending on a person's likelihood of developing a DVT," Sobel says. That means if you have one of the risk factors described above, try to do these every hour while traveling.
1. Seated Ankle Pumps
Ankle pumps are a great exercise to promote blood flow and circulation by activating the muscles in the lower leg and decreasing the risk of blood clot formation, Drainer explains. This muscle contraction helps to pump blood from the legs back up to the heart.
- Sit with your back against your seat and your feet flat on the floor. Ensure that your knees are bent at a 90-degree angle and your upper body is in an upright position.
- Lift your heels off the ground while keeping your toes in contact with the floor.
- Lower your heels back to the floor while raising your toes toward the ceiling.
- Repeat 20 times.
2. Seated Marches
This gentle exercise can help improve blood circulation throughout the cardiovascular system by contracting your leg muscles, Sobel says.
- Sit up tall so that you are not leaning against the back of your seat. Aim to sit on the edge of your chair, if space allows.
- Keep both of your feet flat on the floor with your knees bent at a 90-degree angle.
- Lift one knee about 2 to 3 inches while keeping your other foot in contact with the floor, mimicking the movement of marching. (Engage your core so that your lower back isn't curling or flexing.)
- Slowly lower the lifted knee back to the floor in its original position.
- Repeat the same motion with the other leg.
- Do this 10 to 20 times each leg.
3. Piriformis Stretch
The piriformis muscle runs from your lower spine through your butt to the top of your thighs. It can get aggravated by sitting for long periods of time, and when this muscle gets inflamed or tight, it can compress the sciatic nerve, which runs underneath it. Stretching can help prevent the piriformis from becoming tight, Sobel says.
While this stretch does not directly prevent blood clots, it can contribute to overall leg health and comfort, especially during extended periods of sitting from air travel. It can also relieve muscle tension within the glutes.
- Sit at the edge of your seat with both of your feet flat on the floor. Ensure your back is straight.
- Cross your right knee over your left knee so that your right ankle is near your left knee and pointed out to the side.
- Using your right hand, gently give yourself some pressure downward at your right knee.
- If you need more of a stretch, gently lean forward until you feel a stretch behind your right hip.
- Hold for 30 seconds.
- Return your right leg to its original position and repeat with your left leg.
4. Heel Raises
Heel raises are the optimal exercise to promote blood flow by contracting your gastrocnemius, which is the biggest muscle in your calf, Sobel says. You should complete this exercise only if you can stand from your chair or in the aisle.
- Stand in an upright position on a flat surface. Use the side or back of a seat to provide more stability and support.
- Position your feet about hip-width distance apart with your toes pointing forward.
- Raise both heels off the ground as high as is comfortable. You should essentially be standing on the balls of your feet.
- Pause at the top of the movement where your heels are lifted as high as possible.
- Slowly lower your heels back to the starting position.
- Repeat 20 times.
5. Hip Flexor and Calf Stretch
When we're seated, the hip flexors are in a shortened position, making it easier for them to become tight. This stretch is a beneficial exercise for improving hip flexibility and will help lengthen the muscle, Sobel says. Do this stretch within a range that is comfortable and pain-free.
- Stand with your feet hip-width distance apart.
- Get into a shortened lunge position with your left leg forward.
- Think of elongating the front of the right hip by pushing your hips forward and keeping your trunk upright. You should begin to feel a stretch along the front of your right hip.
- Sneak in a gastrocnemius stretch by pushing your right heel into the ground, which you should feel in your right calf muscle, in addition to your hip.
- Hold for 30 seconds.
- Release and switch legs. Repeat on the other side.
6. Seated Hamstring Stretch
This stretch promotes circulation and improves flexibility of the hamstring muscles, which can also become tight with long-duration sitting, Drainer says. When your hamstrings become stiff they can contribute to low back stiffness and pain.
- Sit with your hips at the edge of your seat. Fully extend one leg out in front of you, with your heel on the floor and your toes pointed up.
- Keep your chest up and your spine long and slowly lean forward, bending at the hips. You should feel the stretch in the back of your thigh.
- Hold the stretch for 20 to 30 seconds.
- Slowly return to an upright position and switch sides. Repeat 2 to 4 times on each side.
Other Ways to Prevent Blood Clots During Air Travel
In addition to the exercises and stretches above, experts say there are other things travelers can do in flight to reduce their risk of blood clots.
Dehydration can increase the risk of blood clots, so drinking plenty of water before and during your flight is important to prevent vasoconstriction, or the narrowing of blood vessels, Sobel says.
Travelers should also avoid drinking coffee and alcohol, as these liquids can cause vasoconstriction. "Water and other liquids will promote vasodilation and effective circulation of blood throughout the vascular system," Sobel says.
Wear Compression Stockings
Sobel says another thing that travelers can do to prevent blood clots is to wear compression stockings during a flight. Compression stockings can help improve blood flow in your legs since they provide gentle pressure to prevent blood from pooling.
Elevate Your Legs
If possible, try to keep your feet and legs elevated. Take advantage of open seats next to you or place a small bag or cushion under the seat in front of you and your feet on top. This can help reduce swelling, promote better blood circulation and lower the pressure in your legs, according to the National Blood Clot Alliance.
In general, moving, walking or standing can be challenging to do on a plane, especially when there is turbulence and limited space. However, if the flight allows, get up and walk around the cabin every couple of hours to help improve circulation. Consider selecting an aisle seat which can make it easier to get up and move around.
Avoid Taking Aspirin
According to the CDC, it is not recommended to take an aspirin to prevent blood clots when traveling. If you currently take aspirin or plan to take aspirin for other reasons, check with your healthcare provider first.
"Blood clots are a very rare but serious condition. Travelers should take the above exercises and advice to help prevent a DVT from forming," Sobel says.
- American Society of Hematology: Clots and Travel.
- Centers for Disease Control and Prevention. Blood Clots and Travel.
- National Blood Clot Alliance. In-Flight Fitness.
- North American Thrombosis Forum. Patients Are Asking: does Flying Increase My Risk for a Clot.
- Centers for Disease Control and Prevention. Prevent Blood Clots.