George: What comes up for me is nearly the opposite concern that you have voiced: Instead of worrying that full speed will hurt uke, my concern is that in a dojo, uke's attacks simply are not realistic enough. A skilled real attacker will not waltz in like a zombie and give his center to you, which is what we tend to do in conventional dojo practice. My experience has been that at higher speeds, along with a higher degree of "sincerity" from uke, most aikido techniques don't work most of the time. Uke just pulls out of them.
(I did one such session with a friend on the mat, after everyone had left. As uke I brought my full intelligence, and though he was a nidan while I was a second qu, again and again I was able to extend out of his usual aikido techniques.
There was one exception, which I should report. While going truly at full speed, he did catch me unaware on a kotogaishe (sp?). It was very similar to a sucker punch in that I just didn't see it coming.
He took me down hard, in a high fall. On the mat it was a great experience, though on the street it would definitely not have been in uke's interest.
But my main point is that for that one time of success, there must have been at least 20 failures.)
So to me, speed is just one variable to take into account with regard to realism, while the sincerity/competence of uke is another. We might go so far as to say that uke can show up at one of three different levels:
Level 1: Zombie walks in and virtually throws himself.
Level2: Uke walks in and will allow you to take his center if you are skilled enough to do so.
Level 3: Uke comes in mindful of protecting his center. If you take it, he will strive instantly to move so as to regain his center. To throw him you have to take his center and keep adjusting to his adjustments. And uke's center is floating rather than locked so you don't know exactly where and when he will be....
My experience is that most dojos limit themselves to Levels 1 and Level 2, and to me, this represents a weakness in training that goes beyond the speed issue. What will happen to the typical student, regardless of years of training, when in the street he makes his move, expecting uke to happily comply,only to find that uke makes an adjustment and the aikido technique fails? What price will we pay for years of protecting our egos? : )
In his Attackproof book, John Perkins makes a passing reference to this. The way he languages it is that it is imperative to train with an "uncooperative" uke from the beginning in order to truly develop the grace necessary to deal with a street attack.
My sense is that Perkins is right, and for me, this trumps a concern regarding the speed (alone) of the training. To me, the challenge is to simulate an intelligent degree of "non-cooperativeness" while still guarding against undue risk of injury.... Jim