The effect of moderate aerobic exercise and relaxation on secretory immunoglobulin A

A deficiency in secretory immunoglobulin A (sIgA) is associated with recurr ent upper respiratory tract infections both in the general community and in elite athletes. The aim of this paper was to investigate the effect of aer obic exercise and relaxation on various indices of sIgA in 12 male and 8 fe male adults who varied in levels of recreational activity. Salivary samples were obtained before, immediately after and 30 minutes after an incrementa l cycle ergometer test to fatigue. after 30 minutes of cycling at 30% or 60 % of maximum heart rate, and after 30 minutes of relaxation with guided im agery. Each session was run on a separate day. When expressed in relation t o changes in salivary flow rate, sIgA did not change after exercise. Howeve r, both the absolute concentration and secretion rate of sIgA increased dur ing relaxation (167 +/- 179 mug ml(-1), p < 0.001: and 37 +/- 71 <mu>g(.)mi n(-1), p < 0.05 respectively). Nonspecific protein increased more than sIgA during incremental exercise to fatigue (decrease in the sIgA/protein ratio 92 +/- 181 <mu>g(.)mg protein(-1), p(0.05), but sIgA relative to protein d id not change during relaxation. Our findings suggest that sIgA secretion r ate is a more appropriate measure of sIgA than sIgA relative to protein, bo th for exercise and relaxation. These data suggest the possibility of using relaxation to counteract the negative effects of intense exercise on sIgA levels.