When it comes to traveling, most frequent flyers worry more about their in-flight movie and meal choices than they do about the actual effects this routine has on their body.

While jet lag is the most known after-flight effect, most people are unaware of the strain their body's circulatory system goes through during a normal flight cross-country.

Almost 2 million people are affected each year by deep vein thrombosis, a circulatory condition that is potentially fatal when not detected or treated in time. DVT is caused by formation of blood clots in the veins of the lower limbs, where blood flow is reduced when a person is sitting for a prolonged period of time. When the blood clot travels to an artery of the lung, it may get stuck and block blood flow. This "pulmonary embolism" often has a fatal outcome.

However, there are a few simple steps travelers can take before, during and after takeoff.

The first step is to keep moving. Even if you are stuck between two snoring passengers, don't hesitate to excuse yourself and take a walk down the aisle (provided the seatbelt light is not on). However, if you are not able to leave your seat, the following tips can keep the blood pumping and ward off post-flight fatigue.

* Elevate feet during flight by propping them on your carry-on luggage or a foot rest if provided.

* Drink plenty of liquids - especially water.

* Perform seated exercises. Try the knee to chest stretch. With both hands clasped around your right knee, bend forward slightly and pull your knee to your chest. Hold the stretch for 15 seconds; then slowly let your knee down. Repeat the same stretch with your left knee. Perform 10 stretches for each leg.

Ankle circle exercises also will help. Lift your feet off the floor and twirl your feet as if you're drawing circles with your toes. Continue this for 15 seconds, then reverse direction. Repeat as desired.

* Take Pycnogenol before takeoff. Pycnogenol is an antioxidant that originates from the bark of the French maritime pine tree. It has been proven in clinical studies to reduce swellings in the legs and feet and decrease platelet activity. Two hours after taking a single Pycnogenol dose, platelet "stickiness" in the blood is lowered.

A recent study also showed that Pycnogenol inhibits production of thromboxane, a dangerous substance produced by activated platelets that can potentially cause a blood clot.