• Christophe Delecluse
  • R. Diels
  • M. Goris
Keywords: athletics, strength, sprint start, force-time curves, principal component analysis, training periodization


By means of good timing in training periodization, sprint coaches strive to realize an optimal transfer of strength gain to improved sprint performance. This study aims to develop a test procedure for the follow-up of specific strength abilities of elite sprinters at selected moments in their training periodization. The sprint start was selected as a standardized test condition as it is very specific and because of the high test-retest reliability in a group of experienced sprinters. The horizontal force-time curves on front and rear starting blocks were analyzed and followed-up 3 times/year (1995-1997) for 20 male and 17 female sprinters. The test sessions were planned in January, April and June, 6 weeks before important competition periods. A principal component analysis with varimax-rotation was performed on 11 selected horizontal force-time related parameters: acceleration, velocity and time of the total start action, and reaction time, maximum force, impulse and take-off time on rear and front blocks. The analysis for the male sprinters included 127 starts and 119 starts for the female sprinters. Four components were extracted: a technique-, a time-, a strength- and a reactioncomponent. These components explained 30%, 24%, 18% and 18% respectively of the total variance in the female parameters. These percentages only differ slightly in the male group: 22%, 24%, 24% and 18%, respectively. The mean start acceleration is normally considered a good indication of the quality of a dynamic start action. In the female group start acceleration was correlated to the technique- (.72) and time-components (-.59) alone. In the group of male sprinters, start acceleration was correlated to the time- (-.61), the strength- (.53), and the technique-components (.45). This indicates that the reaction-component was not performance determining in either the male or the female groups. More surprising was the fact that the strength component was not correlated to the horizontal start acceleration in the female group. In planning strength training, the coach must maintain a delicate balance between the maximum strength, the explosive strength, the rate of force development and the transmutation of the acquired motor potential into athletic performance. A follow- up of the individual scores for the components extracted in this study show that these scores offer valuable information concerning the competition preparedness of athletes in the pre-competition period. By using this standardized test protocol six weeks before the competition period, the coach can determine more accurately the accents for the final training preparation by analyzing the individual component scores.
Equipment / Instrumentation