Yaku soku geiko (practicing in the movement) has been developed to improve the throwing (TORI) and falling (UKE) skills in judo competition. It is the most effective form of exercise to train and learn throwing techniques in the movement.
UKE offers no or only as much as required by TORI, resistance during the executing of the throwing techniques. TORI observes all four phases of throwing, but UKE will do only the desired resistance. TORI does the techniques fluidly and with the necessary body tension. It is important that TORI and UKE will coordinate their breathing, while the implementation of Yaku soku geiko.
Also for the first learning a Kata this training is perfect, because the coordination of the step sequences between TORI and UKE can be practiced best. Later in kata training UKE can build up more and more resistance during the implementation, so that the Kata ultimately looks realistic.