Learn the double dyno in bouldering: leg drive, overshooting and catching with both hands at once. With milestones, typical errors and falling rules.
A double dyno is a jump in which you release both hands from the start holds at the same time and slap both onto the target holds at the same time. In a dyno both feet leave the wall and return once the target hold is caught [1]. The DAV describes the dyno more simply: you take momentum, briefly let go of all holds and catch yourself on the new ones [3]. The honest answer to "Isn't that just a jump?": no. The double dyno is a timing problem in which the legs do the work.
Biomechanics divides the double dyno into three phases like any movement: preparation, execution, stabilization [2]. It belongs to the class "dynamic (2)": there is no margin for error; whoever misses falls and restarts from the ground [2]. And movements faster than about 150–200 milliseconds, roughly a fifth of a second, allow no more correction [2].
Expect a simple double dyno to need some feeling after a few sessions, while a far or high one takes a long time (an experience value, not a measurement).
Entry criteria (practice standard):
Practise the dyno with one hand and a small jump. The federation describes it: both feet leave the wall [1].
Milestone: You catch the target hold five times in a row.
Put both hands on two start holds, hips low, feet on footholds. Check the distance to the target holds.
Milestone: You stand calmly at the start and reach the targets in your head without shaking.
The legs do the work: in jumps the force of the lower extremities was 1.8 times that of the upper ones [2]. Push up with your legs, the arms give the direction.
Milestone: On every attempt you visibly bring the hips up before the hands let go.
Grab slightly before the dead point, that is just before the movement stops: in a study that Dech and Kittel evaluate, success was more likely when the target was overshot and the hand placed just ahead of the dead point [2]. So plan a bit "too far".
Milestone: You catch the target holds three times out of five attempts.
Catch the target holds with both hands at the same time, feet back on the wall. Practise first with big target holds and bring the hips close to the wall right after the catch so the weight does not stay hanging on the arms.
Milestone: You slap both hands onto the target holds at the same time, and both hold.
In the double dyno there is no second chance [2]. Whoever misses, falls. Falls in bouldering are mostly involuntary: in a survey of 245 injured climbers, 85% of the falls were involuntary, 62% included a rotation, 74% landed feet first, and 67% of the injuries affected the lower extremity [4]. In a cohort of 507 boulderers, lower extremity injuries were more often severe and more often caused by falls and jumping off [5]. Practise the landing before the jump, keep the fall zone clear and increase distance and height in small steps. This guide explains and motivates but does not replace supervised training. Have a coach show you falling technique and mat rules.
Do the target look: fix your eyes on the target holds before you push off and do not lose them during the jump. Whoever looks away at takeoff loses the timing. This is practical experience and not proven. The movement itself runs too fast to correct [2], so the look before the start decides.
A double dyno is a jump in which both hands leave the start holds at the same time and catch the target holds at the same time. In a dyno both feet leave the wall until the target hold is caught [1]. You take momentum, briefly let go of all holds and catch yourself anew [3].
First consolidate the simple dyno, then practise leg drive, slight overshooting and catching at the same time. What matters is the landing: practise it before the jump. Increase the distance in small steps.
Usually you pull with the arms instead of pushing with the legs. In jumps the force of the legs was 1.8 times that of the arms [2]. It also helps to overshoot slightly before the hands grab [2].
It has no margin for error: whoever misses, falls [2]. Falls in bouldering are mostly involuntary, and lower extremity injuries are more often severe [4][5]. So: practise the landing, keep the fall zone clear, increase the distance slowly.
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