Techniques are to be executed at the pause, or resting point between the inhalation and exhalation points. This is also the way of breathing during ukemi, as we are to leave no openings in the breath, or mind as we would be susceptible to attack during or just after taking the fall. Technically speaking, the breath, itself, is to be locked before the initialization of Uke's attack. Locking of the breath occurs at the moment when one is neither breathing in or out. This takes substantial practice to understand, and even longer to be able to do during controlled physical activity. To be able to accomplish it when being attacked is even more difficult and should be paramount in one's personal training goals within a martial context. As an aside, the breath is completely effected by the blood and physical constitution and Yin/Yang and Acid/Alkaline balance of one's body. This is why diet becomes so intimately tied to this discussion. This is why O-Sensei's diet, especially that in his later years needs to be more closely observed. Of course, all of this is both studied and practiced as part of O-Sensei's Misogi. This is why O-Sensei's Misogi-no-Gyo needs to be properly learned and practiced in order to understand O-Sensei's Aikido.
I hope that helps.
Do you suggest that the breath is locked during the time of execution of complete technique? Is it something similar as when sprinters run some distance without breathing? Could you elaborate, please?
Technically speaking, the breath, itself, is to be locked before the initialization of Uke's attack.
As initialization really starts first in his mind, the actual physical realization of attack can be delayed few seconds or minutes, should breath be locked all that time?
And last question: what is relation between locking the breath and the realisation of O sensei Misogi?