5 minutes each, still didn't learn a thing

https://imgur.com/a/bvEDznJ

I had problems with one in particular, i tried doing it over and over again but it just doesn't work.

hi, im going to start on what you need to focuse on because i looks like you arent confident in the lines you make i would recommend doing some studys of the "line of action" which is the general line or movement of the person you are drawing focuse on how the spine curves with one line and do a few practices with only focusing on that then when you can identify it almost immediately then you can work on adding the head ribs and hips with simple lines or circles and what can help you under stand the pose more is if you put a cross where the body part is facing then you can start adding the joints and conecting them with a line

When you say you're doing it over and over, what are you redoing? First, I think you might be focusing too much on drawing what you see, rather than making up the rhythm that you feel runs through the figure.Cuz I see nice contours, which shows you can reflect what you see in your drawing, but for these exercises, it's not so much drawing what you saying as 'finding' the rhythm/flow that YOU think represents the figure's movement (and that involves the creative processes of interpretation, exaggeration, and simplification of what you see).The lines are sketchy, which could reflect that you're not confident or feel rushed by the time limit, but spend a few seconds thinking of what line you think runs through the figure before actually marking the paper (and if that means adding 15 more seconds so you can do so comfortably, do so). This might help: first, you can picture, in your head, the line you want on the paper without actually marking the paper. Then, when you see the line clearly, draw it slowly so that you're in control of the pencil the entire time. It might help to "ghost" draw a line a few times--aka, draw your line without putting your pencil to the paper--a few times before actually marking the line. tldr, plan the line you want to draw, "ghost" the line you want to draw, then draw it.

What tends to work for me is that if I get in this situation where like, I feel like I'm practicing AND not learning, to focus on something in particular. Because it's generally that my problem is that "I want to get better" isn't specific enough to actually get better at anything in a way I can actually process.

Now this focus can be anything from "I want to understand arms better" to "I want to draw faster" or whatever you come up with, but I think it'll help to focus on something you can actually parse if it DOES get better.