Can it be done? Should it be done?

[srztanjur]

I know that reflexes are controlled by spinal interneurons. I was just pointing out that somatic reflexes that recruit fast twitch don't necessarily involve slow twitch at all. Also, that wasn't a direct quote. In fact, that wasn't even a summary of something I was reading at the time. That's just me talking from prior knowledge. The source was just there to back me up. However, I want to do some hair-splitting of my own -- I don't believe it's collaterals from the same afferent nerve axons that innervate different types of muscles, but separate axons altogether, drawing from the same circuit, but not necessarily the same interneuron. But, yeah. We agree on the major points, and the relevant one: which is that you can definitely train both without interfering with either one separately.

 

[Gerry Seymour]

Where'd you find that information from? I've taken quite a few anatomy, physiology, and exercise physiology courses, at both the undergraduate and graduate level, and I've never come across anything you've just said.

Here's a quick source that seems to agree with part of it. This is information that seems to be "new" for me (since my days studying physiological psychology).

Muscle Fiber Influence on Motor Neurons | Exercise Medicine
And a PPT file that seems to be related.