Int J Sports Med 2007; 28(2): 116-124
DOI: 10.1055/s-2006-924145
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

Changes in Selected Biochemical, Muscular Strength, Power, and Endurance Measures during Deliberate Overreaching and Tapering in Rugby League Players

A. Coutts1 , P. Reaburn2 , T. J. Piva3 , A. Murphy1
  • 1School of Leisure, Sport and Tourism, University of Technology, Sydney, Australia
  • 2School of Health and Human Performance, Central Queensland University, North Rockhampton, Australia
  • 3School of Medical Sciences, RMIT University, Bundoora, Australia
Further Information

Publication History

Accepted after revision: March 27, 2006

Publication Date:
11 July 2006 (online)


The purpose of this study was to examine the influence of overreaching on muscle strength, power, endurance and selected biochemical responses in rugby league players. Seven semi-professional rugby league players (V·O2max = 56.1 ± 1.7 mL · kg -1 · min-1; age = 25.7 ± 2.6 yr; BMI = 27.6 ± 2.0) completed 6 weeks of progressive overload training with limited recovery periods. A short 7-day stepwise reduction taper immediately followed the overload period. Measures of muscular strength, power and endurance and selected biochemical parameters were taken before and after overload training and taper. Multistage fitness test running performance was significantly reduced (12.3 %) following the overload period. Although most other performance measures tended to decrease following the overload period, only peak hamstring torque at 1.05 rad · s -1 was significantly reduced (p < 0.05). Following the taper, a significant increase in peak hamstring torque and isokinetic work at both slow (1.05 rad · s -1) and fast (5.25 rad · s -1) movement velocities were observed. Minimum clinically important performance decreases were measured in a multistage fitness test, vertical jump, 3-RM squat and 3-RM bench press and chin-upmax following the overload period. Following the taper, minimum clinically important increases in the multistage fitness test, vertical jump, 3-RM squat and 3-RM bench press and chin-upmax and 10-m sprint performance were observed. Compared to resting measures, the plasma testosterone to cortisol ratio, plasma glutamate, plasma glutamine to glutamate ratio and plasma creatine kinase activity demonstrated significant changes at the end of the overload training period (p < 0.05). These results suggest that muscular strength, power and endurance were reduced following the overload training, indicating a state of overreaching. The most likely explanation for the decreased performance is increased muscle damage via a decrease in the anabolic-catabolic balance.


Ph.D. Aaron Coutts

School of Leisure, Sport and Tourism
University of Technology
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Lindfield, NSW 2070



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