The Best Jump Variables To Predict Sprint Performance

[Shawn Chow]

Many have been the attempts to predict sprint performance based of
different tests. In order to predict sprint performance, these tests
should specifically assess the abilities that affect performance at
given phases of the sprint. The aim of this study was to examine the
relationship between the performances at acceleration (ACC), and
maximal running (MAX) sprint phases, and jump selected variables .
Twenty two male sprinters, were assessed for five jump tests: Squat
Jump (SJ), Counter Movement Jump (CMJ), Drop Jump (DJ), Repeated
Vertical Jumps during ten seconds (vRJ10), and 5 horizontal jumps
(5hJ). The best sprint predictors to ACC and MAX are an index between
the horizontal distance and the 5 contact times from 5hJ. The results
are favorable to the use of other variables beside distance jumped
(GRF, velocity, power, and impulse) and also take in consideration the
variable relative to body weight and height.
INTRODUCTION: Success in sprinting events is determined by three major
factors; (1) the athlete's ability for fast acceleration, (2) the
capacity to reach a high running velocity, and (3) the capability to
maintain velocity against the onset of fatigue. The greater the level
of force and the faster that force is applied to the ground in each
stride, the better will be the sprint.
Many have been the attempts to predict sprint performance based of
different tests that mostly evaluate strength and power abilities. In
order to predict sprint performance. These tests should specifically
assess (in terms of movement pattern, conditions of force production,
muscle groups) those physical abilities that affect performance at
given phases of the sprint: the start from the blocks, acceleration
(ACC), and maximal running (MAX).
Jump tests are routinely used by coaches to monitor training progress
in sprint athletes with distance jumped being usually the only measure
that is taken into account . However, in a sport like sprint running,
other variables beside distance jumped , can provide very useful data
as predictors of performance and indicators of fitness level.
The aim of this study was to examine the relationship between the
performance during two phases of the sprint running (ACC, MAX) and
selected variables , from five different jump tests: Squat Jump (SJ),
Counter Movement Jump (CMJ), Drop Jump (DJ), Repeated Vertical Jumps
during ten seconds (vRJ10), and 5 horizontal jumps (5hJ).
Some authors have tried to find relationships between sprint (or
sprint phases) and different kind of tests (to measure muscle
strength). The different methodologies used on those studies have
turned the comparisons very difficult mainly because of the different
type of muscles actions used. We can find studies examining the
relationships between: sprint and stretch-shortening cycle (SSC) tests
(Mero et al., 1981; Nesser et al.1996; Kukolj et al. 1999; Hennessy
and Kilty, 2001; Berthoin et al. 2001; Bret et al. 2002); sprint and
isokinetic tests (Alexander, 1989; Guskiewicz et al.1993; Blazevich
and Jenkins, 1998; Dowson et a. 1998); and sprint and isometric tests
(Mero et al., 1981; Young et al.1995).
We can conclude that the goal of correlation studies to find the best
strength predictors to a sprint run performance is difficult. It
should be noted that correlations can only give associations (strong
or weak) and not cause - effect.
Our option to choose the tests was related to the goal, validity and
reliability of the tests. The squat jump (SJ) and LegPress has been
described as a measure of leg explosiveness in concentric and
isometric conditions The Isometric dynamometry is one of the most
popular methods for assessing neuromuscular function in sport science
as it permits the evaluation of both peak force and rate of force
development.
The countermovement jump (CMJ) assessed leg power in long SSC, the
drop jump (DJ) and the 5 horizontal steps (5hj) a measure of short SSC
performance.Their external validity in athletic assessment is still a
topic of debate (Wilson and Murphy, 1996). While some authors have
found a significant correlation between isometric peak force or rate
of force development and performance of sprinting (Mero et al., 1981;
Young et al., 1995), others have failed to find a significant
relationship between static measures of neuromuscular function and
dynamic performance (Wilson et al.,1995; Kukolj et al., 1999). The aim
of this study was to examine the relationships between the sprint run
and the results obtained in common strength and power tests, which
measure the capability to produce force in isometric, pure concentric
and SSC contraction modes, to discriminate sprint capacity.
Values for times between 0-15m (ACC) and 45-55m (MAX), and distance,
ground vertical force (GRF), power, and impulse, in absolute and
relative terms (weight and height). Squat jump (SJ), counter movement
jump (CMJ), drop jump (DJ), 10" repeated jumps (RJ10), 5 horizontal
jumps (5hJ) (mean ' SD, n=22).
Jump height; vertical ground reaction force (VertGRF); Body weight
(BW); Time between 0-15m (ACC); Time between 40-50m (MAX); Average
distance of 5 jumps (5hJ avgDist); Average distance of 5 jumps
relative to subject height (5hJ avgDistRel); Average height of all
jumps during 10 sec. (RJ AvgHeigth); Average relation between height
and contact time of all jumps during 10 sec. (RJ H/cT Avg); Average
impulse (= force x time) of all jumps during 10 sec. (RJ AvgImpulse);
Average power (= force x velocity) of all jumps during 10 sec.
(RJAvgPower1); Average mechanical power (= g2 ' ft ' 10") / 4n (10" -
ft), ft = Sum of total flight time, n= number of jumps (Bosco, 1983)
(RJAvgPower2); mgh / ct m = mass of subject (Kg), g = acceleration of
gravity (9.81 m.s-2), h = height (9.81 x ft2)/8, ct = contact time
prior to jump (RJAvgPower3).

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