Exercise your feet and legs in your seat, avoid alcohol and drink plenty of water while flying.

These are the most effective ways to prevent the blood clotting associated with long-distance flights, experts say. Now, sports drinks could become the latest addition to these measures.

Earlier this year The Journal of the American Medical Association published a paper suggesting that drinking electrolyte beverages is effective in preventing air travelers from developing deep-vein thrombosis. The Otsuka Pharmaceutical Co. chartered a jet to determine the effect of beverages such as Pocari Sweat on the increase in blood viscosity of passengers on long-distance flights.

Forty subjects were divided into two groups, the first drinking the beverage while the second drank mineral water, at regular intervals. The jet flew 9 hours nonstop from Narita airport to Moses Lake, Wash. The passengers remained seated throughout the flight, except when providing urine samples.

The experiment found that the average urine amount produced by the group who drank the sports beverage was markedly lower than that of the mineral water drinkers. It also suggested that the electrolyte beverage curbed decreases in blood plasma volume and increases in blood viscosity -- conditions that often develop during long-distance flights.

These findings indicate that electrolyte beverages are an effective means of reducing the risk of developing blood clots during air travel.