Funnily enough I had a recent reoccurrence of back pain inherited from 20 years ago, basically a spinal Protusion in the lower lumbar. As it gets more and more painful I find myself doing less and less ukemi. And classes have now gone down to twice a week. It's not getting better, and I'd be kidding I didn't think it's getting worst.
Confounding myself trying to figure out what's wrong I decided to restart gym work which I abandon upon advise of my Sensei and Silat teacher. Well two days on the elliptical and weights have resulted in diminished pain. Thus I agree that the exercise and loading of weights does strengthen the body.
Ukemi is bad for your body. Period. Learning it is smart, continuing to taka falls your whole life is not good for your body. It will not teach your aiki. It will not teach you internal power, you do not need to fall down to "feel your teacher" and learn the waza.
You can learn power and aiki and how to use it, without falling down at all. And in the process some
of the damage will be reversed through training the body correctly.
I continue to prove all of the above, (and not just talk about it) ...month after month as I meet so many of the damaged teachers and players.
Now... Wouldn't it be a surprise that all the exercises you guys are doing in developing fascia, grounding etc... Really was as simple as making your body used to taking lateral loads rather then generic strength training. And that's all it takes for people to do amazing stuff with their bodies. Specialize muscular training and unified usage of those muscles.
Well, the very nature of the question defines the lack of understanding of what it is we do. Taking lateral loads is nursury school and just one of many benefits of proper training. It is far deeper than that and broaches the topic of the connection between internal strength....and Aiki.