The last stride into the take-off board: adjusting without losing speed

What the run-up has to achieve

The approach has two objectives that pull against each other, which are reaching the highest controllable speed and arriving at a precise point on the ground. A jumper who prioritises accuracy will decelerate before the board, which reduces the horizontal speed available to be converted into distance. A jumper who prioritises speed will arrive inconsistently, and a take-off from beyond the board is not measured at all.

The approach is therefore an exercise in achieving accuracy without paying for it in speed, which is why it occupies so much of an athlete's training. The number of strides is fixed and rehearsed so that the whole approach becomes a pattern rather than a sequence of individual decisions.

The correction begins early

Adjusting at the last stride is the least effective option, because a large change made at that point disturbs the take-off posture entirely. The efficient version distributes the correction across the final three or four strides, each of which is altered by a very small amount. This is possible because the athlete has been gathering visual information about the board since well before the final strides.

A jumper who looks at the board late has less distance over which to correct and must therefore make larger adjustments. The result is that consistent jumpers appear not to adjust at all, when in fact they are adjusting continuously and by tiny amounts.

Vision as the control system

The athlete is not measuring distance but responding to how quickly the board expands in the visual field, which encodes both distance and speed. This is why an approach that works in one setting can fail in another, since lighting and background change how that expansion is perceived. It is also why a headwind disrupts the run-up beyond its direct effect on speed, because the relationship between effort and progress has changed.

Athletes rehearse the approach in the conditions of the competition for exactly this reason, and adjust the starting mark rather than the running. A mark moved backwards or forwards by a small distance is a correction to the whole system rather than an admission of a fault.

The penultimate stride

The second-to-last stride is characteristically longer and lower, and it serves to drop the centre of mass before the take-off. Lowering the hips allows the final stride to raise them, which is where the vertical component of the jump is generated. A jumper who does not lower will take off flat and travel a long distance horizontally without the height needed to remain airborne.

The lowering has to happen without deceleration, which is the difficult part, since the instinct when lowering the body is to shorten and slow. The final stride is then shorter and faster, planting the foot beneath the body so that the ground contact is as brief as possible.

Why speed matters more than the take-off

The distance achieved depends heavily on the horizontal speed carried into the take-off, and no amount of technique at the board compensates for a slow approach. The take-off converts a portion of that speed into vertical movement, which means it is redistributing an existing quantity rather than creating one. A long ground contact at the board converts more speed into height and loses more of it to braking, which is why the contact is kept short.

This is why sprinters convert to the event more readily than athletes with better jumping technique and less speed. It also explains why a foul is such an expensive outcome, since the jump that produced it was usually the fastest approach of the competition.