Effect of Duration of a Moderate Exercise Program on Primary and Secondary Immune Responses in Mice

Background and Purpose. Moderate exercise conducted over a 4- to 8-week period enhances secondary antibody response and is mediated, in part, by endogenous opioids. Because changes in circulating levels of endogenous opioids occur after each exercise session, the researchers in this study tested the hypothesis that a shorter exercise program of 2 weeks may be sufficient to enhance secondary antibody response. Another purpose of this study was to examine the effects of a moderate exercise program completed prior to the primary immunization on the secondary antibody response in mice. Subjects and Methods. Young (8- to 10-week-old), syngeneic, female C57BL/6 mice were randomly assigned to exercise (2 or 8 weeks) and sedentary intervention protocols. Mice were immunized against human serum albumin (HSA), and serum anti-HSA antibody levels were measured (in micrograms per milliliter) using an enzyme-linked immunosorbent assay (ELISA). Results. The secondary antibody response was comparable in mice exercising for 2 or 8 weeks and was enhanced over sedentary controls. Discussion and Conclusion. A moderate exercise program of 2 weeks may be sufficient to improve secondary antibody production and may be a useful strategy to enhance antibody response to vaccinations in humans. Furthermore, an exercise program that includes exercise prior to the primary immunization in addition to exercise following primary immunization may not provide additional enhancement of secondary antibody response.