Changes in exercise performance and hormonal concentrations over a big ten soccer season in starters and nonstarters

William J. Kraemer, Duncan N. French, Nigel J. Paxton, Keijo Häkkinen, Jeff S. Volek, Wayne J. Sebastianelli, Margot Putukian, Robert U. Newton, Martyn R. Rubin, Ana L. Gómez, Jason D. Vescovi, Nicholas A. Ratamess, Steven J. Fleck, J. Michael Lynch, Howard G. Knuttgen

Research output: Contribution to journalArticlepeer-review

232 Scopus citations


As a consequence of the physiological demands experienced during a competitive soccer season, the antagonistic relationship between anabolic and catabolic processes can affect performance. Twenty-five male collegiate soccer players were studied throughout a season (11 weeks) to investigate the effects of long-term training and competition. Subjects were grouped as starters (S; n = 11) and nonstarters (NS; n = 14). Measures of physical performance, body composition, and hormonal concentrations (testosterone [T] and cortisol [C]) were assessed preseason (Tl) and 5 times throughout the season (T2-T6). Starters and NS participated in 83.06% and 16.95% of total game time, respectively. Nonstarters had a significant increase (+1.6%) in body fat at T6 compared to T1. Isokinetic strength of the knee extensors (1.05 rad·sec-1) significantly decreased in both S (-12%) and NS (-10%; p ≤ 0.05) at T6. Significant decrements in sprint speed (+4.3%) and vertical jump (-13.8%) were found at T5 in S only. Though within normal ranges (10.4-41.6 nmol·L-1), concentrations of T at T1 were low for both groups, but increased significantly by T6. Concentrations of C were elevated in both groups, with concentrations at the high end of the normal range (normal range 138-635 nmol·L-1) at T1 and T4 in NS and T4 in S, with both groups remaining elevated at T6. Data indicate that players entering the season with low circulating concentrations of T and elevated levels of C can experience reductions in performance during a season, with performance decrements exacerbated in starters over nonstarters. Soccer players should therefore have a planned program of conditioning that does not result in an acute overtraining phenomenon prior to preseason (e.g., young players trying to get in shape quickly in the 6 to 8 weeks in the summer prior to reporting for preseason camp). The detrimental effects of inappropriate training do not appear to be unloaded during the season and catabohc activities can predominate.

Original languageEnglish (US)
Pages (from-to)121-128
Number of pages8
JournalJournal of strength and conditioning research
Issue number1
StatePublished - Feb 2004

All Science Journal Classification (ASJC) codes

  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation


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