Sprint test and timing gates
A technical report has been published by The Norwegian olympic federation, Norwegian university of science and technology and the inter-university laboratory of human movement and biology of Savoie Mont Blanc University in France. The study is about methodological and practical considerations when doing a sprint test using timing gates. There are three variables measured for the study: power, force and velocity. The report aims to investigate the impact of timing gate setup on mechanical outputs in sprinting athletes.
There is a discussion over how many timing gates use to accurately calculate the sprint mechanical output. Morin and Samozino study says that there must be no less than 5 timing gates. However, present findings show valid and reliable outputs are obtained with fewer checkpoints. In fact, using only three split times is more than enough.
Data confirms timing distances shorter than 30m won´t be completely accurate, since peak velocity is achieved at 25-30 meters. For valid and reliable results, the entire acceleration phase of sprinting athletes must be covert.
Current findings reveal some measurements in timing setups are less sensitive to change and more reliable than others. Not considering these “small” timing errors lead to larger errors in horizontal acceleration data. To reduce timing errors, previous studies show that trial repetition decreases the typical error.
Considering these studies, mechanical output values reduce by half after four sprint repetitions. While in practice, maximum sprint repetition is challenging due to fatigue. Haugen studies show how a junior soccer team player can stand a fifteen 20m set with a 60 second recovery. All sets without fatigue. At the same time, in longer distances fatigue starts earlier. In the 40m sprint test, fatigue starts at the third/ fourth round despite recoveries up to 6 minutes. When designing sprint test protocols, these findings must be taken into consideration.
Considering the study results, three split times are enough to obtain valid and reliable information of the acceleration phase. One every ten meters to time the whole acceleration curve of the sprint test. To reduce errors, it is best to repeat at least four times the exercise.