Success on the progress using breathing methods and posture adjustments
I am definitely not an expert on running techniques or even just running in general. What I do find myself to be good at though, is being very stubborn and not giving up and I think that is a good attitude to have if you are trying to improve your cardio.
My latest goal has been to get my 5k pace comfortably below 7 minutes and 30 seconds per km, which isn't really even that fast. However, with me, I was not that long ago severely overweight and then got my size down by dieting and lifting weights. I became pretty damn ripped in that process but as anyone that has tried to do bodybuilding, power-lifting, and also cardio, you quickly find out that it isn't really possible to excel at all 3, especially if you are in your 40's before you ever started to take this sort of thing seriously.
I started focusing more on cardio recently, although I do still hit the weights but mostly for compound exercises on my upper body. My "leg days" don't exist in the gym... that is what cycling and running are for. Bodybuilders and power-lifters generally don't do much cardio, some don't do any at all. But for me, as I got older, my focus started to be more on overall general health and being muscular, even though it looks good, isn't really that fantastic for your overall health. Some studies have shown the opposite in fact, especially if PED's are involved.
Anyway, I have really put my head down and tried to get better at cardio in a general sense and it feels kind of good to see some actual improvement.

This is a run I did yesterday evening in the hopes that it would have cooled off a bit. It had, but it was still extremely hot and I was totally saturated by the end of it.
At the start of the run I was still contending with pedestrians and traffic but once it opened up on this one track of land that I have found that for whatever reason others avoid I was able to really get moving. A little bit too much in fact.

When I looked at my watch during the 2nd km I was actually getting a bit concerned about the fact that I was going too fast. For more seasoned runners perhaps this is more evident to them but I was kind of feeling quite energetic and the music was just right that was going into my ears but when I looked down and saw that at some points I was running less than 6.5 minutes per km, I know that this is too fast for me and I am only going to gas out. The good news is that I corrected this and was able to finish with a time that I am quite happy with, a full 29 seconds per km faster than what I had intended.
My eyesight isn't the best and I refuse to run with glasses on so sometimes I can't really see how fast I am going... this is something that I perhaps can and should change in the settings of my Xiaomi 2 watch.
Once again though, the watch is a blessing and a curse because as I got closer to the fictional "finish line" the last 200 meters or so seemed to be longer than the previous 4800 meters. I guess that is just a mental thing. If there was an actual finish line I think it would have compelled me to work harder but with the only finish line existing inside my watch's calculations, it is very taxing on me mentally and I start to get angry at how long it is taking... I think others have felt like this before as well.
I also have ordered some of these things

I'm not really sold on the performance aspects of these things because it sounds like marketing bullshit to me but they aren't expensive (like $10) and for me, I am mostly wearing them because of the excessive sweating and inevitable buildup that happens in my shoes. During my 8km fast run the other day I started to develop blisters from the moisture that made its way into my shoes and I am hopeful that these compresses will soak up a lot of that. My feet don't really sweat all that much because I use moisture wicking socks and spent some good money on some high tech shoes that if you look closely, actually have mesh "ports" on the sides to allow water to get out.
We'll see... they will arrive in a few days.
In the meantime I am just delighted that I have moved not just to 7 min 30 but well past it. Just like my Strava title said, this didn't really even feel difficult to me. now let's see if I can do it that easily twice in a row.
Today is going to be a cycling day as I give my knees and back a day to recover.