BIOLOGY OF EXERCISE VOL. 7.1, 2011
KLIMENTINI MARTINOPOULOU, POLYXENI ARGEITAKI, GEORGIOS PARADISIS, CHRISTOS KATSIKAS, ATHANASIA SMIRNIOTOU
Department of Physical Education and Sport Science, University of Athens
This piece of research aimed to determine the effect of resisted and un-resisted forms of sprint training on both acceleration and top speed, as well as several kinematic variables. In thiscase resistance was provided by a parachute.
16 competitive sprinters were selected as subjects. Each having at least 4 years of sprint training behind them. The authors did not give us any idea about the level of the selected athletes though.
The subjects were evaluated using a 50 m sprint from a ‘standing crouch’ position. Photocells were located at the 10, 20, 40, 46 and 50 m points of the run. Additional information about each athletes stride length, stride frequency, contact time, and flight time was attained using an optical measurement system by Microgate™.
The subjects were then divided into two groups, the first group underwent a 4 week training program consisting of parachute resisted sprints performed three days a week. Each session involved four maximum sprints over 30 m and four over 50 m. Each run separated by either 4 or 6 minutes of recovery. Care was taken by the researchers to use a parachute which did not impede each athletes speed by more than 10%. The parachute used by all participants was the Power Chute™ size large. The control group performed the same protocol but without the added resistance of the parachute.
At the 4 week point all athletes were re-evaluated.
Statistically significant improvements were observed in the parachute group over 0-10 m, 10-20 m, 0-20 m and 40-50 m. The un-resisted group improved over 0-20 m only, and this improvement was not as great as that seen in the parachute group.
During the acceleration phase the parachute group increased their stride length, and at top speed they increased their stride frequency while decreasing their flight time. No kinematic changes were observed in the control group.
Thanks to Martinopoulou and his associates in the Department of Physical Education and Sport Science, at the University of Athens, we now know that parachute resistance can improve both acceleration and top speed. Furthermore these improvement appear to be due to alteration in stride length, stride frequency and flight time.