Effects of ascorbic acid supplementation on immune status in healthy women following a single bout of exercise

Abstract

This study was designed to determine the effects of ascorbic acid (AA) supplementation on immune status following a single bout of exercise. In a crossover design, 20 healthy sedentary women performed 30 min moderate-intensity cycling with (1000AA) or without (0AA) ingesting 1000 mg of AA daily for 1 week. Blood samples were taken immediately before, immediately after and 24 h post-exercise to determine the oxidative stress markers, immunophenotyping of peripheral blood lymphocytes and neutrophil phagocytic function. Moderate-intensity exercise in participants ranged in age from 21 to 23 years, showed no significant changes in oxidative stress markers in both cohorts. Plasma total creatine kinase was increased immediately after exercise and returned to baseline at 24 h post-exercise in both cohorts. Participants ingesting 1000 mg AA demonstrated significant higher level of plasma AA at pre-exercise and post-exercise as compared with the same time point in 0AA group. White blood cell and absolute neutrophil counts were increased immediately after exercise in both cohorts. Exercise resulted in increased lymphocyte count, CD4 + and CD8 + T cell counts immediately after exercise (p < 0.05) in 0AA group. AA supplement mitigated effects of exercise on CD4 + T cells. No significant change in neutrophil phagocytic function were observed when incubated with low or high concentrations of Candida albicans in both cohorts. These results suggested that a single bout of moderate-intensity exercise caused muscle injury with increased absolute CD4 + and CD8 + T cell counts, accompanied by a transient increase in neutrophil count, while their phagocytic function was not changed. However, a short-term AA supplementation does not show beneficial effects on exercise-induced changes in leukocyte subpopulations.