Effects of a 12-week training programme on selected hormonal and psychological parameters and their interrelationships in highly-trained male and female swimmers

Abstract

Swimming training load (TL) is regarded as a major stimulus for hormonal adaptation, but research findings are inconsistent. Methodological limitations also exist (e.g., cross-sectional sampling) with little knowledge of acute hormone responses and hormone-psychological interactions that regulate training outputs. These issues were addressed in a 12-week training study on highly-trained swimmers. Eighteen swimmers (10 males, 8 females) completed a 12-week training programme, involving a stepwise reduction in TL before a major competition. Testing was conducted from Monday-Friday at week one (T1), week five (T2), and week 12 (T3), including measures of salivary testosterone and cortisol, willingness to train, stress, and sleep quality. Post-session hormones were assessed on Mondays and Fridays. Daily-averaged swimming distance decreased by -21% (T2) and -57% (T3), relative to T1 (p < 0.001). We found no significant training effect on the cortisol and testosterone measures, both baseline and acute exercise response, willingness to train, and sleep quality. Only stress varied with training, decreasing significantly at T2 and T3 from T1 in female swimmers. Among male swimmers, daily changes in baseline cortisol and testosterone were related (r = 0.45) at T1, as was sleep quality and stress (r = 0.39) at T3. In summary, highly-trained swimmers showed little or no adaptive changes prior to a major competition. The one exception was self-reported stress among female swimmers, which decreased along with TL. The emergence of daily interrelationships (in male swimmers only) between selected hormonal or psychological outputs could provide a new lens to assess pre-training preparation.

Keywords: Anxiety; Endocrinology; Overtraining; Recovery; Tapering.

FIG. 1

Swim-training intensity at the start (T1), middle (T2), and end (T3) of the 12-week training programme. Top plot shows the percentage of training performed at different intensity zones: Z1 (blood lactate < 1 mmol/l; skills), Z2 (1–3 mmol/l; aerobic), Z3 (3–5 mmol/l; aerobic), Z4 (> 5 mmol/l; anaerobic), and Z5 (maximal effort or sprint training). Bottom plot depicts the daily-averaged rating of perceived exertion (RPE) across the AM and PM swim training sessions.

FIG. 2

Marginal means (error bars represent the 95% CI) for daily-averaged swimming distance at the start (T1), middle (T2), and end (T3) of the 12-week training programme. *Significant difference between test occasions.

FIG. 3

Marginal means (error bars represent the 95% CI) for the baseline hormonal and psychological measures at the start (T1), middle (T2), and end (T3) of the 12-week training programme. 1Significantly different from women at T1, T2 and T3, 2Significantly different from women at T1, *Significant main effect of sex.

FIG. 4

Marginal means (error bars represent the 95% CI) for the acute hormonal response to exercise at the start (T1), middle (T2), and end (T3) of the 12-week training programme. *Significant hormonal change from baseline (i.e., 95% CI excludes zero).