Influence of a fed or fasted state on the s-IgA response to prolonged cycling in active men and women.
This study investigated the effect of a fed or fasted state on the salivary immunoglobulin A (s-IgA) response to prolonged cycling. Using a randomized, crossover design, 16 active adults (8 men and 8 women) performed 2 hr of cycling on a stationary ergometer at 65% of maximal oxygen uptake on 1 occasion after an overnight fast (FAST) and on another occasion 2 hr after consuming a 2.2-MJ high-carbohydrate meal (FED). Timed, unstimulated whole saliva samples were collected immediately before ingestion of the meal, immediately preexercise, 5 min before cessation of exercise, immediately postexercise, and 1 hr postexercise. The samples were analyzed for s-IgA concentration, osmolality, and cortisol, and saliva flow rates were determined to calculate s-IgA secretion rate. Saliva flow rate decreased by 50% during exercise (p < .05), and s-IgA concentration increased by 42% (p < .05), but s-IgA secretion rate remained unchanged. There was a 37% reduction in s-IgA:osmolality postexercise (p < .05), and salivary cortisol increased by 68% (p < .05). There was no effect of FED vs. FAST on these salivary responses. The s-IgA concentration, secretion rate, and osmolality were found to be significantly lower in women than in men throughout the exercise protocol (p < .05); however, there was no difference between genders in saliva flow rate, s-IgA:osmolality ratio, or cortisol. These data demonstrate that a fed or fasted state 2 hr before exercise does not influence resting s-IgA or the response to prolonged cycling. Furthermore, these results show lower levels of s-IgA and osmolality in women than in men at rest.
Allgrove
Judith E
JE
School of Science, University of Greenwich at Medway, Kent, ME4 4TB, UK.
Geneen
Louise
L
Latif
Sarah
S
Gleeson
Michael
M
D001642:Bicycling / Q000502:physiology*; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism*; D005215:Fasting / Q000378:metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis / Q000378:metabolism; D007070:Immunoglobulin A / Q000378:metabolism*; D008297:Male; D009752:Nutritional Status; D009994:Osmolar Concentration; D010101:Oxygen Consumption; D019518:Postprandial Period / Q000502:physiology*; D012463:Saliva / Q000378:metabolism*; D012737:Sex Factors; D055815:Young Adult
D004040:Dietary Carbohydrates; D007070:Immunoglobulin A; D006854:Hydrocortisone