IN-VIVO CELL-MEDIATED-IMMUNITY AND VACCINATION RESPONSE FOLLOWING PROLONGED, INTENSE EXERCISE

Epidemiological and experimental studies have shown increased frequenc y and severity of infections after intense, long-term exercise. This s tudy examines whether an in vivo impairment of the cell-mediated immun ity and antibody production can he demonstrated after intense, long-te rm exercise. Twenty-two male triathletes performed one-half an ironman (group A). Vaccinations with tetanus and diphtheritis toroid and puri fied pneumococcal polysaccharide were given after the exercise. Furthe rmore, a skin test with seven different antigens was applied on the fo rearm. Antibody titers were measured before and 2 wk after the exercis e. The skin test was read 48 h after the application. Eleven non-exerc ising triathletes (group B) and 22 moderately trained men (group C) we re used as control groups. Group A revealed a significantly lower skin test response to the tetanus antigen than both groups B and C. In gro up A, a smaller cumulative response (sum of the diameters of induratio ns and number of positive skin test spots) was found than in both grou ps B and C. No differences in antibody titers were found among the thr ee groups. Thus, the in vivo cell-mediated immunity was impaired in th e first days after prolonged, high intensity exercise, whereas there w as no impairment of the in vivo antibody production measured 2 wk afte r vaccination.