Salivary IgA responses to prolonged intensive exercise following caffeine ingestion.

Purpose: Prolonged, intensive exercise is associated with a reduction in concentration and secretion of salivary IgA (s-IgA). Saliva composition and secretion are under autonomic nervous system control, and caffeine ingestion, a widespread practice among athletes for its ergogenic properties, is associated with increased sympathetic nervous system activation. Therefore, this study investigated the influence of caffeine ingestion on s-IgA responses to prolonged, intensive exercise.

Effect of caffeine ingestion on lymphocyte counts and subset activation in vivo following strenuous cycling.

Caffeine ingestion is associated with increases in the concentration of plasma epinephrine and epinephrine is associated with alterations in immune cell trafficking and function following intensive exercise. Therefore, the purpose of this study was to investigate the effect of caffeine ingestion on plasma epinephrine concentration, lymphocyte counts and subset activation in vivo, as measured by the expression the CD69 surface antigen, before and after intensive cycling. On two occasions, following an overnight fast and 60 h abstention from caffeine containing foods and drinks, eight endurance trained males cycled for 90 min at 70% O(2 max) 60 min after ingesting caffeine (6 mg kg(-1 )body mass; CAF) or placebo (PLA).

Effect of prolonged exercise and carbohydrate on total neutrophil elastase content.

Purpose: The purpose of the present study was twofold: first, to assess the effect of prolonged intense exercise on total neutrophil elastase content in endurance-trained cyclists and to determine whether this is associated with postexercise falls in lipopolysaccharide (LPS)-stimulated neutrophil elastase release; and second, to determine the effect of carbohydrate (CHO) ingestion during exercise on these responses.

Methods: In a randomized design, nine trained male cyclists cycled for 2 h at 75% VO(2max) on two occasions with either CHO (6.4%, i.