Brief Report: Training load, salivary immunoglobulin A and illness incidence in elite paratriathletes

Purpose: To gain an exploratory insight into the relationship between training load (TL), salivary secretory immunoglobulin A (sIgA) and upper respiratory tract illness (URI) in elite paratriathletes. Methods: Seven paratriathletes were recruited. Athletes provided weekly saliva samples for the measurement of sIgA over 23 consecutive weeks (February - July) and a further 11 consecutive weeks (November – January). sIgA was compared to individuals’ weekly training duration, external TL and internal TL, utilising time spent in pre-determined heart rate zones. Correlations were assessed via regression analyses. URI was quantified via weekly self-report symptom questionnaire. Results: There was a significant negative relationship between athletes’ individual weekly training duration and sIgA secretion rate (p = 0.028) with changes in training duration accounting for 12.7% of the variance (quartiles: 0.2%, 19.2%). There was, however, no significant relationship between external or internal TL and sIgA parameters (p ≥ 0.104). There was no significant difference in sIgA when URI was present or not (101% vs 118% healthy median concentration; p ≥ 0.225); likewise, there was no difference in sIgA when URI occurred within two weeks of sampling or not (83% vs 125% healthy median concentration; p ≥ 0.120). Conclusions: Paratriathletes’ weekly training duration significantly affects sIgA secretion rate, yet we did not find a relationship between external or internal TL and sIgA parameters. Further, it was not possible to detect any link between sIgA and URI occurrence which throws into question the potential of using sIgA as a monitoring tool for early detection of illness.