Analysis of Stride Parameters and Running Velocity at Indoor 400 M Running

Abstract

Background. 400 m race is one of most difficult and complex events in athletics. In order to achieve good results
in the distance an athlete must have not only good velocity characteristics, but also be able to tactically correctly
allocate them, i.e. depending on their total and special endurance level be able to distribute efforts in the entire range,
select the optimum running velocity for the start and keep it until the finish. Research aim was to analyse the choice
of running tactics and change of stride parameters and running velocity of the best Lithuanian 400 m runners during
a running indoor contest.
Methods. The study was conducted during Lithuanian Indoor Championship. The best 15 runners of 400 meters
were investigated. The runners were filmed by Digital cameras from the side at a distance of 90, 190, 290 and  
390 meters. We analysed stride kinematic parameters (duration of support and flight, stride length, stride frequency)
and the running velocity.
Results. The maximum decrease of the stride length and running velocity were observed between 190 and
290 m where the stride length decreased from 2.22 ± 0.03 to 2.08 ± 0.03 m and running velocity from 8.18 ± 013
to 7.36 ± 0.07 m/s. In the first distance range, i.e. 90 m, the stride frequency was 3.83 ± 0.05 Hz. Later it gradually
decreased to 3.46 ± 0.05 Hz in 390 meters. Duration of support at 90 m was 0.119 ± 0.001 s and till 290 m it become
longer, later it was almost unchanging. Time of flight phase changed insignificantly over the entire distance.
Conclusion. It was found that athletes’ choice of running tactics depended not only on their preparation type
(sprint or endurance), but also on the conditions in which the athlete starts (indoor or outdoor), as well as on the
number of the track in which the athlete starts. The maximum change of running velocity and stride length during the
indoor running was observed in the second half of the range, while the stride frequency decreased gradually during
the entire range. Change of support time had greater impact for stride frequency than change of flight time.

Keywords: stride frequency, stride length, duration of support, duration of flight, tactics.