大学男子駅伝選手の常圧下低酸素環境を利用したトレーニングにおける魚油製剤摂取の効果

Abstract

kn-abstract=We investigated that the effects of the 'live high-train low' methods using normobaric hypoxia with or without fish oil supplement on the endurance performances. Twelve male ekiden-runners in the university were divided into two groups; one group (non-fish oil group, n=6) spent in normobaric hypoxic room 8 h per day (equal to ~2500 m) for 3 weeks, the other group spent in the same condition for the same period with supplementation of fish oil for 7 weeks (fish oil group, n=6). Administration of the fish oil supplement was started 4 weeks prior to using hypoxic environment. The blood examinations were performed before and after the total experimental protocol, and the running tests using treadmill machine were conducted before and after using hypoxic environment. The concentrations of eicosapentaenoic acid (EPA) in the blood in the fish oil group significantly increased from 77.2±16.8 to 126.5±11.2 μg/mL. Hemoglobin concentrations (Hb) and hematocrit levels (Ht) were significantly increased after hypoxic training in the non-fish oil group. However, in the fish oil group, both Hb and Ht were not significantly changed after using hypoxic environment. The lactic acid levels in the running test at 18.8-19.4 km/h in the non-fish oil group and at 20.6 km/h in the fish oil group were significantly decreased. We also estimated the speed of onset of blood lactate accumulation (SP-OBLA). Although SP-OBLAs in both groups were slightly increased after using hypoxic environment, there was no significant difference between the two groups. It was concluded that the 3 weeks of 'live high - train low' methods using normobaric hypoxia with fish oil supplement may improve the endurance performances without increase of Hb and Ht. It is speculated that fish oil supplementation reduces the cardiovascular loading via increase of Ht during hypoxic training without blunting the improvement of endurance performance.