Int J Sports Med 1992; 13(7): 534-541
DOI: 10.1055/s-2007-1021312
© Georg Thieme Verlag Stuttgart · New York

Physiological Changes in Male Competitive Cyclists after Two Weeks of Intensified Training

A. E. Jeukendrup, M. K. C. Hesselink, A. C. Snyder*, H. Kuipers, H. A. Keizer
  • Dept. of Physiology, University of Limburg, Maastricht, The Netherlands
* A. C. Snyder was a fulbright scholar at the University of Limburg during this study. Permanent address: Department of Human Kinetics, University of Wisconsin, Milwaukee, USA.
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Publication History

Publication Date:
14 March 2008 (online)


To study the physiological response to heavy training, seven male competitive cyclists intensified their normal training program for two weeks (IIT) in order to achieve a state of short-term overtraining. The subjects underwent a graded cycle ergometer test to exhaustion, an outdoor 8.5 km time trial and a computerized test to study reaction time and visual perception, before, during and after the two weeks of intensified training and after two weeks of recovery. Furthermore subjects kept a daily log in the form of a questionnaire. After two weeks of IIT all subjects showed symptoms of overtraining: the general state of well being declined as indicated by the questionnaire while performances on time trial (x̄±SEM: 830±14sec-871±19sec), contests and maximal power output (x̄±SEM: 336 7watt-310±5 watt) declined significantly. Maximal (x̄±SEM 11.8±l.1 mmol·l-1-5.9±0.5 mmol·l-1) and submaximal lactate values were significantly lowered during ergometer test after the IIT, while the workload at the 4 mmol point increased significantly (x̄±SEM 234±10watt-267±13watt). Sleeping heart rate increased significantly (x̄±SEM 49.5±9.3BPM-54.3±8.8BPM). Maximal heart rate (x̄±SEM 185±3BPM-178±2BPM, mean heart rate during the time trial (x̄±SEM 178±2BPM-169±2BPM) and V̇O2max (x̄±SEM 4801±121ml·min-1-4409±101 ml·min-1) were all significantly lowered by the IIT. No significant changes were found in body weight and fat, in RT (x̄±SEM 260±12ms-251±7ms) and PT (x̄±SEM 79±4% - 83±4%). After two weeks of recovery a state of super-compensation was observed. All variables returned to their reference level or showed an improvement although the subjects still felt tired. This is indicative for over-reaching (22). We conclude that lowered maximal and submaximal lactates in combination with decreased performance and declined maximal heart rates can indicate a state of over-reaching. In addition increased heart rate during sleep is also indicative. From a time trial, finishing time and mean heart rate can be used as additional measurements to indicate imminent or early overtraining in male competitive cyclists.