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Saliva immunoglobulin A (IgA) and cortisol levels were measured in 21 male members of a major midwestern swim team. Saliva samples were collected before and after training sessions four times during the fall season; the training intensity was light, moderate, heavy and during the taper period before a major competitive meet. Saliva IgA levels were decreased after each training session, reaching statistical significance with the moderate training intensity. Over the 3-month training period the pre-session and post-session IgA levels both decreased significantly during the heavy and taper training intensities later in the fall season. Cortisol levels were significantly elevated only after the heavy-intensity training session. The Profile of Mood States (POMS) was used to assess the swimmers' overall mood on each test day. No significant correlations were found between the global POMS score and IgA or cortisol. Also, cortisol and IgA were not significantly correlated except after the light training session. Results from this study indicate that acute bouts of exercise can reduce salivary IgA levels and that chronic exercise of high intensity can reduce the resting levels of IgA. These changes may render the athletes more vulnerable to respiratory infections after exercise and even at rest during the later stages of the competitive season.

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Two experiments were performed to examine salivary immunoglobulin A (s-IgA) responses to varying levels of exercise intensity and duration. For experiment 1, 9 college men (mean age, SD = 23.56, 1.64 years) completed treadmill runs of 15, 30, and 45 min at approximately 60% of maximum oxygen consumption (VO2max). For experiment 2, 9 other college men (mean age, SD = 23.67, 2.0 years) ran for 20 min at approximately 50, 65 and 80% of VO2max. Unstimulated salivary samples were collected before, and immediately, 1 and 2 h after the exercise. Samples were assayed for s-IgA using an enzyme-linked immunosorbent assay. Mean s-IgA levels did not change significantly (P greater than 0.05) at any of the post-exercise collection times when compared to pre-exercise levels. The results of this investigation indicated that running at intensities of 50-80% of VO2max and for durations of 15-45 min did not affect s-IgA levels.

The purpose of this study was to investigate potential improvements in the methodology associated with the Physical Working Capacity at the Fatigue Threshold (PWCFT) test including: (1) the use of a continuous test protocol; (2) the use of a treadmill; (3) the use of a bipolar EMG lead system for noisy electronic environments; and (4) the potential for residual fatigue from tests repeated 24 hours apart. The results of the continuous test protocol (mean +/- S.D. = 210 +/- 73 watts) correlated well (r = 0.856) with the original discontinuous technique (222 +/- 83 watts) and there was no significant (p greater than 0.05) difference between the mean values (t = 1.146). Treadmill testing required a bipolar lead system to counteract the electrical noise generated by the treadmill motor. The heart rate values which corresponded to PWCFT on the treadmill (mean +/- s.d. = 164 +/- b.p.m.) and bicycle ergometer (153 +/- 18 b.p.m.) were highly correlated (r = 0.833) and there was no significant (p greater than 0.05) difference between the mean values (t = 2.22). The use of a bipolar lead EMG system on the bicycle ergometer resulted in significantly (p less than 0.05) smaller voltage for any given power output, and the PWCFT exhibited a low to moderate correlation (r = 0.60) with PWCFT derived from a unipolar arrangement. The test-retest results of discontinuous PWCFT measurements performed 24 hours apart on the bicycle ergometer were correlated at r = 0.812 with no significant (p greater than 0.05) difference (t = 0.52) between the mean values (test = 198 +/- 60; retest = 191 +/- 63 watts).(ABSTRACT TRUNCATED AT 250 WORDS)