PURPOSE: To analyze the effects of the progressive relaxation technique to reduce/control blood cortisol levels in swimmers during a period of training. METHODS: Swimmers of both sexes (n = 23) were divided into two groups: experimental EG (n = 11), which was submitted to the progressive relaxation technique session twice a week; control CG (n = 12), which was submitted to a placebo treatment under the same conditions. The treatments lasted for seven weeks with three blood samples (pre, mid and post tests). RESULTS: Starting from the distribution non-normality showed by the Kolmogorov-Smirnov test (Dmax = 3.61 > Dcritical = 0.276, p= 0.05), the exploratory analysis reveals the following cortisol (ng/ml) median values in the pre, mid and post tests, respectively: EG = 140.7; 95.5, and 86.5, and CG = 141.1; 132.8, and 138.6. Besides this greater reduction in the EG median values, the EG values were closer to median in the posttest, which did not happenned in the CG. To corroborate this tendency, the Mann-Whitney test was used, depicting a significant statistical difference (p < 0.004) for EG, which did not occur in CG (p > 0.05), depicting a greater cortisol level reduction in EG compared to the CG. CONCLUSION: The results indicate that the experimental treatment (progressive relaxation) influenced the reduction of blood cortisol levels. These results show an intense psychophysiologic relationship between human body processes, indicating the need to use training strategies to prevent excessive stress.
Cortisol; Psychophysiology; Physical training; Relaxation
