• Take-off distance-Horizontal distance from the front edge of the barrier to the take-off toe
• Crouching height-The vertical distance from the top of the barrier to the center of masswhen the center of mass is directly above the barrier
• Push-off angle-Knee angle of the push-off leg as the athletes leaves the barrier.
• Landing distance- Horizontal distance from the front edge of the barrier to the landing toe at touchdown
• Velocity through jump divided by average race pace (v/p)-Average velocity from 5 m prior to the barrier to 2.5 m past the water pit divided by average race velocity
• Approach velocity-Average velocity from 5 m prior to the barrier to 2.5 m prior to the barrier
• Exit velocity-Average velocity from the far edge of the water pit to 2.5 m past the water pit

Two stepwise multiple linear regressions were completed (one for men and one for women) with v/p as the dependent variable and all the variables listed above other than exit velocity as the independent variables.

Velocity divided by race pace was chosen as the dependent variable since runners have to return to race pace following the water jump. If they can keep from slowing too much during the water jump, there will be less acceleration required as they exit the water pit. However, coaches and athletes should realize that increasing this variable indefinitely is not advisable. Since seven jumps were measured for each athlete, the average value for each variable was inputinto the regression model. A repeated measure ANOVA was performed to determine differences between genders in all the variables listed above. Finally, the repeated measures ANOVA was performed again after normalizing the variables (other than crouching height and push-off angle) for race pace. This allowed us to determine whether any differences between genders could be accounted for by differences in race pace.

Velocity through the jump divided by race pace (v/p) was predicted very well by approach velocity and landing distance for men and women (Table 1). All other variables were removed as they did not make significant contributions to increasing multiple R² values.

The relationships of v/p with all parameters showed linear trends throughout the range of measured values. However, only three variables were found significantly different after normalizing by race pace. Variables that appear to be due to gender alone rather than just different race paces include: Push-off angle (greater for women), exit velocity (smaller for women), and loss of velocity (greater for women) (Table 2).

Women and men both showed linear trends in the v/p regression model throughout the range of measured values. There was no apparent local maximum in the relationships between v/p and approach velocity or landing distance. Thus, increasing approach velocity or landing distance through the ranges of these athletes should increase v/p further. However, it is important to keeping in mind that a higher v/p value is not necessarily advantageous, because economy of movement must be considered in the steeplechase. None of the athletes in this study approached the water-jump barrier at their maximum velocity or attempted to maximize their landing distance. If they had, the current regression model predicts a higher v/p. While this may seem desirable at first, the large fluctuation in effort would likely result in a much greater energy cost (Billat et al., 2001).

While only seven water-jumps occur in a 3000 m steeplechase race, the obstacle must have some effect on running time since it takes athletes away from their normal running stride. The most important factor in steeplechase performance is physical conditioning (Kenney and Hodgson, 1985). With the water-jump making up only about 1% of the total race distance, even a weak correlation between v/p and race pace encourages us to believe that v/p is an appropriate variable to consider in steeplechase performance. This correlation was observed and was very small (R² = 0.02, F = 4.04, p = 0.046).

In order to complete a water-jump obstacle close to race pace (v/p close to 1. 00), one must obtain relatively high approach velocity. Average approach velocities were5.32 m/s (5:02 minutes/mi) and 6.16 m/s (4:21 minutes/mi) for women and men respectively. While many may think an increased v/p is desirable, an approach velocity could become too high. Since economy is so important in the steeplechase, it is possible to go too high above race pace. Another important factor to consider is landing distance. The athletes that are more successful at the water-jump land relatively close to the end of the water-pit. These athletes typically get only one foot wet with each jump (the second foot plant is beyond the water-pit). This matches with the average landing distance values found in this study (2.54 m and 2.85 m for women and men respectively, p < 0.001). Since the pit is 3.66 m long, those with a lower v/p are landing deeper and typically getting both feet wet before exiting the water pit.

Approach velocity and landing distance were expected to be correlated with v/p. Perhaps the more interesting finding of this study is the lack of significance of other variables. This may explain why many world-class steeplechasers appear awkward in their movements over the water jump. As long as their approach velocity is high and they obtain a relatively long landing distance, the other aspects of their technique do not relate to v/p.

The water-jump produces a greater disruption in running velocity in the women than in the men. Exit velocity was greater for men even after accounting for race pace while approach velocity was not. Demonstrating this idea further, loss of velocity was greater for women after accounting for differences in race pace. The lower exit velocities after accounting for race pace might be explained by the pit being the same length for men and women. Since women do not jump as far as men, they will be landing deeper in the water. They are also jumping from a lower height, which results in a decreased flight time compared with the men who jump from a greater height.

Women extend at the knee more than men as they push off the barrier. Pushing off the barrier through a greater extension may help women obtain a greater landing distance, partly overcoming their slower approach velocity and lower barrier height. Crouching height is no different even though body heights are typically different. Since women are taking off from a lower barrier height in the steeplechase water-jump, they may be crouching less to obtain a greater take-off height and increase flight time to get a longer jump.

One limitation to the current study is the lack of information about body height. Some of the gender differences may be due to body height rather than gender alone. Thus, the reason for some gender differences remains unknown.

While technique differences exist between men and women in the water-jump, the movement is similar. The same focus should be given to men and women in terms of what makes a successful water-jump. Increasing approach velocity leads to greater v/p. However, it should be realized that increasing v/p indefinitely is not desirable due to the required economy of a 3000 m race. Working towards an optimal v/p should be focus of steeplechasers. Coaches and athletes should realize that other small differences in technique occur between elite men and women, but they have little impact on the overall performance of the water-jump.

• Women may need to be coached differently than men in the steeplechase water jump due to different techniques required.
• Men and women must focus on a high approach velocity to complete the steeplechase water jump successfully.
• Men and women must generate a relatively long landing distance to maintain velocity and keep from having to use extra energy exiting the water pit.
• Women's race paces were affected more than men's by the water jump in a negative way.