Dave de Vos
In the beginning, my shoulders were hurting after classes with a lot of rolling, but it slowly got better. My left shoulder took longer to get better than my right shoulder.
Now they don't hurt anymore, even after classes with a lot of rolling. It took me about 100 dojo hours.
Following a 35 year hiatus from Aikido I have just completed my sixth consecutive week back attending classes. I am finding ukemi to be the hardest thing to "remember" how to do properly and I too have had sore shoulders to show for it. Eventually, getting down to the right weight, building core strength and regular stretching should help me "remember" quite a bit of what I have forgotten about ukemi. I'm finding suwari waza ryote-tori kokyu ho to be something I remember fairly well however. I believe this is due, at least in part, to the fact that almost every class I took years ago ended with this basic practice.