Wow! SO much fantastic info here - I will resteem it, because I'll need to read it a few times for it to sink in!
It raised many thoughts - fast twitch muscles being responsible for eye movements, for example. I suppose that's why when people get elderly their eye movements slow down. And the size of the muscles – as a climbing fanatic, I've noticed that really good climbers are often so strong that they can do amazing things with their bodies, yet they tend to be lithe, with small muscles all over the place! When you see a really good climber on the wall (there's a cafe with balcony seats at the climbing centre I go to) EVERY single muscle in their body is active from the face to the toes.
I also do indoor bouldering, where the upper body is used a lot. Women, I've heard, often have lower scapular strength - ie the shoulder girdle is often not so strong - as men. We often have to focus on building strength in this area. I've been doing this, but when I sprained my ankle at the end of August, I took complete rest for a month, and my strength is only just beginning to return to what it was.
Last Friday I was at my bouldering club, and I noticed that I'd become quite fearful of some of the high-level routes. I kept quitting as they got higher. With one route in particular, I felt I was almost there, but just couldn't bring myself to finish the last two moves. All the guys could do it, but only one woman. The guys were making it look so easy. Eventually I steeled myself, and went for it. I completed it, but not as easily as the guys. Then I realised that my "fear" was actually realisation that my scapular strength wasn't quite back to what it had been. It was almost there, but not to the point where I could trust myself to support my body with just one arm.
Many of the other women in the club don't think they can do these overhanging routes at all - but they can! It just takes us a bit more perseverance and focus on that shoulder area, and it actually doesn't take as much time or effort as you'd think. You don't have to lift weights or anything. I just do some yoga and a few pull-down exercises, as well as climbing, which builds strength.
Well, I've rambled on a lot, but that's because I find muscles fascinating! Great post :)