title: Monitoring for overreaching in rugby league players.
abstract: The aim of this study was to identify indicators of non-functional overreaching (NFOR) in team sport athletes undertaking intensive training loads. Eighteen semi-professional rugby league players were randomly assigned into two pair matched groups. One group completed 6 weeks of normal training (NT) whilst the other group was deliberately overreached through intensified training (IT). Both groups then completed the same 7-day stepwise training load reduction taper. Multistage fitness test (MSFT) performance, VO2 (max), peak aerobic running velocity (V (max)), maximal heart rate, vertical jump, 10-s cycle sprint performance and body mass were measured pre- and post-training period and following the taper. Hormonal, haematological and immunological parameters were also measured pre-training and following weeks 2, 4 and 6 of training and post-taper. MANOVA for repeated measures with contrast analysis indicated that MSFT performance and VO2 (max) were significantly reduced in the IT group over time and condition, indicating that a state of overreaching was attained. However, the only biochemical measure that was significantly different between the IT and NT group was the glutamine to glutamate (Gln/Glu) ratio even though testosterone, testosterone to cortisol (T/C) ratio, plasma glutamate, and CK activity were significantly changed after training in both groups. Positive endurance and power performance changes were observed post-taper in the IT group confirming NFOR. These changes were associated with increases in the T/C ratio and the Gln/Glu ratio and decreases in plasma glutamate and CK activity. These results indicate that although there was no single reliable biochemical marker of NFOR in these athletes, the Gln/Glu ratio and MSFT test may be useful measures for monitoring responses to IT in team sport athletes.
authors.affiliation: School of Leisure, Sport and Tourism, University of Technology, Sydney, Kuring-gai Campus, Lindfield, NSW, Australia. Aaron.Coutts@uts.edu.au
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Coutts
authors.forename: Peter
authors.initials: P
authors.lastname: Reaburn
authors.forename: Terrence J
authors.initials: TJ
authors.lastname: Piva
authors.forename: Greg J
authors.initials: GJ
authors.lastname: Rowsell
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D052283:Creatine Kinase, MM Form / Q000097:blood; D012090:Cumulative Trauma Disorders / Q000097:blood / Q000503:physiopathology*; D017079:Exercise Tolerance; D005538:Football; D018698:Glutamic Acid / Q000097:blood; D005973:Glutamine / Q000097:blood; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010101:Oxygen Consumption; D010807:Physical Endurance; D005082:Physical Exertion; D011446:Prospective Studies; D015203:Reproducibility of Results; D013739:Testosterone / Q000097:blood; D013997:Time Factors
chemical_list: D015415:Biomarkers; D005973:Glutamine; D018698:Glutamic Acid; D013739:Testosterone; D052283:Creatine Kinase, MM Form; D006854:Hydrocortisone