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

Background: This study was designed to determine the effects of ascorbic acid (AA) supplementation on immune status following a single bout of exercise. Materials/Methods: In a crossover design with a 1 week wash-out period, 20 healthy sedentary women performed 30 minutes moderate-intensity cycling with (1,000AA) or without (0AA) ingesting 1,000 mg of AA daily for 1 week. Blood samples were taken immediately before, immediately after and 24 hours post-exercise to determine the oxidative stress markers, hematological parameters, immunophenotyping of peripheral blood lymphocytes and neutrophil phagocytic function with Candida albicans. Results: Moderate-intensity exercise in subjects 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. Subjects ingesting 1,000 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 and returned to baseline at 24 h post-exercise in both cohorts. Exercise resulted in increased lymphocyte count, CD4+ T cells, CD8+ T cells, CD45+/CD3-/CD4- cells, CD45+/CD3+/CD4- cells, CD45+/CD3-/CD8- cells, CD45+/CD3+/CD8- cells and CD45+/CD3-/CD8+ cells immediately after exercise (p<0.05) with a return to baseline at 24 hours in 0AA group. AA supplement mitigated effects of exercise on CD4+ T cells and CD45+/CD3-/CD8- cells. No significant change in neutrophil phagocytic function were observed when incubated with low or high concentrations of C. albicans in both cohorts. Conclusion: A single bout of exercise induced muscle damage and transient changes in neutrophil count as well as lymphocyte subpopulations in sedentary women. Ascorbic supplementation does not show beneficial effect to the moderate-intensity exercise.