NON-FUNCTIONAL OVERREACHING IN SWIMMERS IS MOST ASSOCIATED WITH EXCESSIVE TRAINING VOLUMES
Matos, N., Willliams, C., & Winsley, R. (2009). Non-functional overreaching in young swimmers over an eight-month competitive season. A paper presented at the 14th Annual Congress of the European College of Sport Science, Oslo, Norway, June 24-27.
This study followed a group of young swimmers over an eight-month competitive season assessing the relationship between training load and the occurrence of non-functional overreaching, and its association with physiological and psychological measures. Seven national-level swimmers (M = 3; F = 4) with a mean age of ~15.4years were monitored. Training load was monitored over eight-months using the Stress Index Scale (Mujika et al., 1995). Data collection was performed monthly and involved determination of Immunoglobulin A and cortisol levels from a salivary sample, and the completion of the Training Distress Scale (Raglin & Morgan, 1994). Incidence of upper respiratory tract infections was also recorded. A submaximal 7 x 200 m step test was performed twice during the eight-months with blood lactates, heart rates, and rates of perceived exertion collected. S were classified as non-functional overreaching if their competitive performance had stagnated or decreased over a period of weeks to months.
Two females were classified as non-functional overreaching. Competitive performance had stagnated/decreased for more than six months although they continued to train. The remaining swimmers improved performance during the season. The non-functional overreaching swimmers monthly swim mean volumes were greater compared to the normal swimmers. There was no evidence of higher mean cortisol in the non-functional overreaching swimmers compared to the normal swimmers. Absolute Immunoglobulin A and the incidence of upper respiratory tract infections did not show conclusively in the two non-functional overreaching swimmers. Training Distress Scale scores relative to the non-functional overreaching period were 54% and 32% greater than those of the normal swimmers. The submaximal performance test data displayed no clear association with non-functional overreaching.
Implication. These data indicate that young swimmers may become non-functional overreachers and that high training volumes may be implicated. Furthermore, high Training Distress Scale scores may be useful in identifying young swimmers at risk of non-functional overreaching, but measures of cortisol, Immunoglobulin A, or upper respiratory tract infections incidence rates have limited confirmatory use.