That is all completely correct.
kewl!
I'm kind of forcing the lean but I think I'm still kind of looking for my optimal sprint technique because I wasn't able to sprint during the initial 4 months after my pcl tear and I did a very high amount of hip flexor strengthening, a muscle I hadn't really worked as an isolated muscle group before. I'm still kind of transitioning from "weight room mode" to "ultimate frisbee mode", so it kind of makes sense that my body is still sort of looking for the ideal running form. I believe the "upright pull running" was the form I was the fastest with before my injury, but maybe now it's different. Will look to test soon.
One disadvantage to the "quad dominant high stride freq" running is I can't breathe properly with it and if I really want the fastest time I think I hold my breath. It is much more exhausting on my lungs and I believe because I'm using less of that sort of reactive plyometric bounce that I would be in upright running it is also much more taxing on the muscles.
to me, the breathing issue is just to you getting used to the different cadence etc.. I mean, it sounds like you are thinking about your breathing too, which is definitely going to impact it. If you train using this "faster & potentially more natural form" for a little bit, you'll probably forget about how you're breathing, and it'll feel natural.
i mean it's just like in slower running too .. people running @ 170 SPM, trying to figure out 180 SPM, they are thinking about all kinds of different things .. but eventually they settle into it after a few weeks or months of training, then they forget about all of those details and just do it.
I think fatigue helps also .. one way to not think about much, is to hold back a bit and perform more reps with a bit shorter rest, just don't even give your brain much to think about other than focusing on completing the next rep etc.
I sometimes laugh at how much I think early on in a workout, and then by the middle to end i'm not thinking about anything other than trying to hit my goal. lmao.
I'm not sure about less plyometric bounce. I imagine it's still pretty similar, except you might be getting a bit more absorption from the quads. Regardless, if your stride freq is going up and your speed is improving, i'd say that in itself implies more "bounce", just not the kind of "bounding bounce" you get from a bound or increasing stride length dramatically, but that's just more air time. If the goal is linear speed, there's a point where that air time becomes detrimental, which could be what was happening with your more upright + longer stride length form.
IMHO, if you are faster with this technique - actually faster not faster by feel, i'd stick with it for a bit and see what happens. Try to ignore things like breathing etc.. Obviously you'll be thinking about it but just tell your brain to "F OFF" and try to just get those thoughts out of there.. you really just want your body to kick in and do everything for you, the "motor programming loop" is faster & more efficient that way.
my 2cents.
pc!!!