To examine the considerations in conditioning for foreign expedition with prolonged air travel, we investigated the changes in condition accompanied with long air flight among the Japanese top athletes. The athletes who participated in the 14th Asian games (2002/Busan) as Japanese delegation carried out a survey by questionnaire on foreign expedition in 2002, regarding experiences of change in their condition and the influence to performance at the competition, and behaviors in the air plane during flight. We collected the effective data from five hundred twenty nine (529) athletes. The most frequent country for expedition is China, following as France, United States of America, Australia, and Canada. Two hundred fifty (250) athletes have experiences of swell of crus and pain of low back and crus in the past. One hundred forty one (141) athletes also deteriorated their condition due to prolonged travel. In forty one (41) athletes, the deterioration of their condition influenced their performance at the competition. About three hundred ninety (390) to four hundred fifty (450) athletes did not arrange the timing or content of breakfast, dinner or sleep at the days before travel or on the day on travel, in consideration of difference in time. The higher occurrence behaviors in the airplane are sleeping, reading books, listening music, and watching movie video. However, the occurrences of exercises such as stretching, massage, flexibility exercise, and easy training were low. Many athletes drunk beverages such as tea, coffee, water, or alcohol, and took care of warming body and preventing to dry nose and/ir tgriat. As they are kinds of diuretic drinks and easily make the athletes dehydrated, athletes should be advised to take isotonic drinks with minerals. These findings suggested that prolonged air travel accompanying with foreign expedition influenced condition of Japanese top athletes, which was related with performance at the competitions. We concluded that fluid intake to prevent dehydration, lower exercise to faciliate peripheral blood circulation, and attention to timing and volume of sleeping and meals before and during travel were needed to prevent the deterioration of condition in Japanese top athletes. Then, disorder of circadian rhythm related with jetlag characterized by fatigue, sadness and sleep problems were discussed to resynchronize on the local time. Consequently subliminal problems during expedition were clarified to improve conditioning of representative athletes. Coaches should educate the importance of conditioning during prolonged air travel to athletes.