When you fall into a lean like effect where you push through word after word as though not to let it block and it actually seems to get us through what we need to say but in a strenuous way, what is happening?

When you fall into a lean like effect where you push through word after word as though not to let it block and it actually seems to get us through what we need to say but in a strenuous way, what is happening? I noticed someone doing this yesterday and it instantly reminded me of what I would go through and maybe still fall into here and there today...like when I talk about a light breath out with sound to keep from locking up, it may fall into this as well but because around college years I tended to repeat, I had forgotten about this phenomenon. What is happening when we fall into this strenuous way of talking? I used to call it pushing a mountain of nothing, it felt like a struggle but there was nothing really there, it's not like I was pushing something physically but the way I would talk to keep out of a block, it almost sounds like I was doing something physically strenuous. I hope that's a clear picture of it, I was tempted to make a video because I thought it would be hard to explain what I'm talking about. So I am just wondering what is happening physically to us when we do this and if it can shed some more light for stutterers. Why does it kind of work? We can still talk yet clearly we are strained and talking shouldn't require it, so what is actually happening? Why does it kind of work? What are we overriding in doing it?