Exercise immunology: Future directions for research related to athletes, nutrition, and the elderly

This article examines three questions related to exercise immunology: 1) Ca n exercise attenuate changes in the immune system related to aging? The few research papers available suggest that the answer may be "yes", but exerci se training may have to be long-term and of sufficient Volume to induce cha nges in body weight and fitness before any change in immunity can be expect ed in old age. 2) Is the athlete an immunocompromised host? For most athlet es, probably not, although the answer may be 'yes' during certain periods w hen the athlete exceeds normal training limits or competes in endurance eve nts. Most stud ies have reported that the immune systems of athletes and no nathletes in the resting state are more similar than disparate with the exc eption of natural killer cell activity which tends to be elevated in athlet es. Infection rise may be more related to the acute changes in immunity tha t occur following heavy exercise, but this hypothesis has not been sufficie ntly studied. 3) Are nutrition supplements effective countermeasures to exe rcise-induced inflammation and immunosupprossion? Except for carbohydrate, the answer at this time for all other nutrients studied is 'no'. While data from the vitamin and mineral studies have been negative, and those involvi ng glutamine conflicting, several investigations indicate that carbohydrate compared to placebo ingestion is associated with attenuated hormonal and i mmune responses.