Recently a lot of athletes carry out high-altitude training for the improvement of their endurance.
In high altitudes, oxygen partial pressure gets low and a living body goes hypoxic state, which induces erythropoiesis resulting the increase of RBC count. The increase of RBC count maintains the amount of oxygen supply even after the person comes back to the level land, which is supposed to bring benefits to an athlete performing. But there is an adverse event. The increase of RBC count causes high blood viscosity with high hematocrit, and will burden the heart through cardiovascular and peripheral rheology.
This time we had a randomized study with fish oil concentration (EPA:1.6g/day) vs. placebo(olive oil) for thirteen weeks. The subjects were twelve male long-distance runners in a training session, which included a training at about 3000m above sea level, . A term of training project carried out the level land at 10-weeks and high altitude training at 3-weeks.
Consequently, the amount of EPA in RBC membrane after the training increased twice as much as that of before the training. In placebo group a tendency of increasing RBC count was observed and it wasn' t in EPA group. This result indicates that RBC deformability and peripheral rheology have been improved in EPA group.
As the increase of RBC count heavily burdens the heart of athletes in an intensive training in high altitudes, constant long-term ingestion of EPA would contribute to them improving cardiovascular function and endurance, which is beneficial to their athletic achievement.
