Abstract: The composition of the invention contains an n-3 highly unsaturated fatty acid as the active ingredient and has the capability of removing a risk factor during exercise, particularly the capability of preventing athletic anemia. The highly unsaturated fatty acids and/or derivatives thereof, preferably eicosapentaenoic acid and/or docosahexaenoic acid. It is most preferably in the form of a natural triglyceride, particularly a fish oil. The composition may be used as a medicament or a food composition, particularly a food for sports. In the case of the medicament, the composition derivative is a pharmaceutically acceptable salt, ester, or amide. The capability of removing a risk factor refers to the capabilities of improving the maximum oxygen intake and increasing the anaerobic threshold value by at least 3%. In this case, the composition serves as a food for enhancing the exercise capacity of persons with a normal healthy body.