The effect of Chlorella pyrenoidosa supplementation on immune responses to 2 days of intensified training

Purpose Periods of intensified training are associated with immune disturbances, The aim was to investigate the effects of supplementation with Chlorella pyrenoidosa ( Chlorella ) on secretory IgA (sIgA) responses to 2 days intensified training. Methods Twenty-six subjects (age 29.1 ± 8.7 years; VO 2max 53.7 ± 11.7 ml kg min −1 ) provided resting saliva samples for determination of sIgA, at baseline (week-0) and following 4, 5, and 6 weeks (weeks-4, -5, -6) of daily supplementation with 6 g/day Chlorella ( n = 13) or placebo (PLA, n = 13). During week-4 a 2-day intensified training period was undertaken [morning and afternoon sessions each day, respectively: VO 2max test; high-intensity interval training (HIIT, 3 × 30 s Wingate sprints); 90 min at ~60% VO 2max ; 3 × 30 s HIIT]. Results Chlorella increased resting sIgA secretion rate (trial × time, P = 0.016: no change with PLA but increases with Chlorella at week-4, week-5 and week-6, P = 0.020,