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Approach speed and performance in the horizontal jumps:
What do Brazilian athletes do?
By Nelia Alfano Moura, Tania Fernandes de Paula Moura, Joao Paulo Borin
Introduction
The long jump and triple jump are athletic events known as
the "horizontal jumps", whose goal is after a preparatory approach run to cover
the furthest horizontal distance by means of a single jump (long jump) or a
sequence of three jumps (triple jump). To facilitate the study of these events,
it has been proposed to split the total distance jumped into partial distances,
and then to identify the determining factors for each. For the long jump, HAY
(1981) classifies the following partial distances as shown in Figure 1.
D1 Take-off distance: the horizontal distance between
the anterior edge of the take-off board and the vertical projection of the
centre of gravity (CG) at the instant of take-off.
D2 Flight distance: the horizontal distance covered by
the CG while the athlete is free in the air.
D3 Landing distance: the horizontal distance between
the vertical projection of the centre of gravity at the instant the heels touch
the sand and the mark from where the jump will be measured.

For the triple jump, each partial distance is repeated three
times as shown in Figure 2.

The distance D2 represents more than 85% of the total
distance of a jump and thus has the highest relationship with the final result
(HAY, 1986). We can say that D2, and thus performance in the horizontal jumping
events, is determined by the same four factors affecting movement of all
projectiles (HAY, 1981): take-off height, angle and velocity, and air resistance
(Figure 3).

It seems take-off velocity is the most important factor
affecting D2 (HAY and REID, 1985), and it has a very high relationship with the
velocity at the touchdown of the take-off foot at take-off (r = 0.87; P <
0.0001), which in turn is dependent on the approach velocity (r = 0.81; P <
0.001), according to data from FUKUCHI et al. (2003). In other words, the faster
the athlete runs, the greater the horizontal velocity at the instant he/she
touches the take-off board and the greater the take-off velocity. We can easily
monitor approach velocity using photoelectric cells.
This study had the following goals: a) to determine the
relationship between approach velocity and performance in the horizontal jumps
at the 2003 Brazilian national championships; b) to verify if approach velocity
differs between long jumpers and triple jumpers when we consider national elite
athletes; and c) to discuss individual relationships, in comparison with values
achieved by the group studied.
Methods
Thirty-two male athletes participants at the
"Troféu Brasil de Atletismo 2003" were studied, 23 competing in the long jump
and 16 in the triple jump (seven competed in both events). Official result and
approach velocity were the variables studied. Brower Inc.@ wireless photocells
were placed beside the runway, 6m and 1m before the take-off board (Figure 4),
allowing us to calculate the mean approach velocity (mIs-1).
Pearson linear relationship and the Mann-Whitney test were used to analyse the
results.

Results and Discussion
The results are shown in Tables 1 to 4. Tables 1 and 2 show descriptive values
for age (years], result (metres], time for the 5m interval (seconds) and
velocity in this interval (metres per second), for the long jump and triple
jump, respectively.


Table 3 shows the correlation between approach velocity and performance, with
higher values for the long jump.

Since 2003, a database has been developed with results from different competitions. The aim is to store a significant amount of information regarding different athletes in order to determine individual relationships between approach velocity and performance. A preliminary analysis of the available data shows that these individual relationships tend to be smaller than that found in the group (Table 4). In other words, although we can generically affirm that faster athletes are able to jump further, we cannot always say that when a particular athlete runs faster he will perform better.

There is another question to be discussed: do long jumpers approach the board
faster than triple jumpers? Data shown in Tables 1 and 2 indicate that this is
the tendency, although the difference is not statistically significant. The
Mann-Whitney test was used, and it is worth mentioning that the calculated P
value (0.0516) is very close to the level of significance adopted for this study
(P < 0.05).
High correlation values between approach velocity and
performance were expected, particularly in the long jump. Many authors believe
that approach velocity is the most important factor determining results in the
long jump (JARVER & BOASE, 1984; MOURA & MENDES, 1983; POPOV, 1982; WALTERS,
1986; ZOTKO & PAPANOV, 1984), and correlation coefficients between 0.7 and 0.9
have been found frequently (HAY, 1993). We have to remember that the closer to
1.0 the stronger the relationship. The lower correlation values found in triple
jump may indicate that more factors influence performance in this event. This
weaker relationship has been reported before by HUTT (1989).
It is usual to see coaches telling their athletes to approach
the board faster. This can be justifiable during practice, but it is
questionable if this advice will always bring positive results in competition.
We have seen that the individual relationships between approach velocity and
performance may in some cases be low or even negative (the athlete jumps a
lesser distance when he/she runs faster).
This apparent contradiction can be easily explained. For a
long time, we have been aware that approach velocity must be optimal rather than
maximal. HAY (1993) affirms that the athlete has three goals to accomplish
during the approach run (Figure 5), and often the search for a higher velocity
negatively affects the other goals. SMITH Et LEES (2003) believe the balance
between velocity, strength and technique is of utmost importance. When running
velocity is increased, ground reaction forces (GRF) also increase, demanding
higher levels of special strength.

We cannot forget that vertical GRF produced during triple jump represents the
highest values measured during sports activities (AMADIO, 1985; HAY, 1993).
Development of specific strength is a prerequisite for the efficient use of a
higher approach velocity. In addition, when the condition to generate force and
velocity changes, timing (technique) must be adjusted. Nowadays, there is no
agreement on whether special physical conditioning and technique should be
developed in parallel or sequentially (VERCHOSHANSKY, 1990; RITZDORF, 1998). In
any case, it is important that, the velocity, strength and technique present a
balanced development during the competitive period.
Conclusion
This study has shown that approach velocity is highly related
to performance in the horizontal jumping events. This relationship is greater in
the long jump, probably indicating that performance in the triple jump is
determined by a larger number of factors. Individual relationships usually show
lower values in comparison to the group. Approach velocity has the tendency to
be greater in the long jump, even though the differences found in this study
were not statistically significant. The tendency towards lower approach
velocities in the triple jump remains intriguing, and deserves more
investigation. New studies are also necessary to determine the factors that
guarantee optimal use of approach velocity.
Acknowledgment
The authors thank Dartfish Latin America, which kindly
permitted the use of its software DartTrainer Team Pro@ for the production of
the illustrations in this article.
FROM: IAAF/NSA 3-05

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