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The IAAF carries out research at its championships, or employs sports scientists to do so on their behalf. A team analysed the male and female long jump finalists at the 2008 Indoor World Championships in Valencia, looking specifically at take-off. Analysis was made via the use of high speed cameras.
A focus, for example, was made of the time the jumpers spent on the board and the way their muscles – and more specifically – their muscular actions worked to transfer them into the jump.
When a jumper’s leg hits the board a “stretch-reflex” occurs. The muscles of the ankles, knees and hips go on stretch (eccentric muscular action), there’s then a minute time delay (amoritization phase) before the jumper’s muscles ping back from the stretch to propel the jumper into the air (concentric muscular action).
The male jumpers had an eccentric phase that lasted between 40ms and 56ms and the concentric phase 72ms to 80ms. The total take-off time for all male jumpers averaged 122ms and for women 117ms. It was discovered that the women spent more time absorbing the contact on the board compared to men (the eccentric phase).
All jumpers lose speed at take-off (the research identified a 10.3% loss for the women and 8.7% for men) – minimising loss of speed is crucial to maximising distance jumped.
The researchers write:
“The compression (eccentric) phase is decisive for achieving the required braking so that the horizontal velocity built up in the approach run can be transformed into vertical impulse. In this phase the jumper accumulates elastic energy; the fact that it is so short proves the jumpers’ extraordinary ability to complete such transformation."
Benefits to us coaches and athletes
Strangely – but is often the case with this type of research - the researchers didn’t provide any practical advice i.e. “do this or that’s”.
So here's what I recommend:
Ref: IAAF New Studies in Athletics no. 3./4.2013
See a video below from my youtube channel on developing improved long jump take-off. Please subscribe to the channel!