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

Abstract

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.

Overtraining - over-reaching - exercise - training - performance - cycling - lactate