Little is known about the relationship between training load and non-functional overreaching (NFOR) in child swimmers. Due to the multifactorial nature of NFOR, previous work has recommended a multidisciplinary framework to address this topic (Matos and Winsley, 2007). The purpose of our study was to follow a group of young swimmers over an 8-month competitive season and assess the relationship between training load and the occurrence of NFOR, and its association with physiological and psychological measures. Seven national-level swimmers (3 males and 4 females) with a mean age of 15.4±1.0 yr volunteered to participate. Training load was monitored over the 8 month period using the stress index scale (Mujika et al., 1995). Data collection was performed monthly and involved determination of Immunoglobulin A (IgA) and cortisol (C) levels from a salivary sample, and the completion of the Training Distress Scale (TDS; Raglin and Morgan, 1994). Incidence of upper respiratory tract infections (URTI) was also recorded. A submaximal 7x200m step test was performed 2 times during the 8-month period with blood lactates, heart rates and rates of perceived exertion collected. Athletes were classified as NFOR if their competitive performance (main swimming event calculated by the 2004 FINA International Points Score) had stagnated or decreased over a period of weeks to months (Meuusen et al., 2006). Of the 7 athletes, 2 females (F3 and F4) were classified as NFOR. Competitive performance had stagnated/ decreased for more than 6 months (F3`s performance stayed the same and F4 had a 6% decrement, even though they continued to train); all other athletes improved performance (8±9.8 % improvement) during the season. The NFOR swimmers monthly swim mean volumes (6-month NFOR period) were 31% (F3; 11.4km) and 22% (F4; 31.7km) greater compared to the non NFOR swimmers (8-month period). There was no evidence of higher mean cortisol in the NFOR swimmers (NFOR period) compared with the non-NFOR swimmers (8-month period). Absolute IgA and the incidence of URTIs did not show conclusive results on the F3 and F4 swimmers. TDS scores relative to the 6-month NFOR period were 54% (F3; 2.8) and 32% (F4; 1.9) greater than those of the non-NFOR swimmer (8-month period). The submaximal performance test data displayed no clear association with NFOR. These data indicate that young swimmers may become NFOR and that high training volumes may be implicated. Furthermore, high TDS scores may be useful in identifying young swimmers at risk of NFOR, but measures of cortisol, IgA or URTI incidence rates have limited confirmatory use. Non-functional overreaching in children is a complex phenomenon and requires more research into the underlying causes for the development of applied diagnostic tools. Matos & Winsley, 2007. J Sp Sci Med, 6:353-367. Meuusen et al., 2006. Eur J Sp Med, 6:1-14. Mujika et al., 1995. Can J Sp Sci, 20 (4),395-406. Raglin & Morgan, 1994. Int J Sp Med, 15: 84-8.
© Copyright 2009 14th annual Congress of the European College of Sport Science, Oslo/Norway, June 24-27, 2009, Book of Abstracts. Veröffentlicht von The Norwegian School of Sport Sciences. Alle Rechte vorbehalten.