To give some good tips.
You don't want to copy the person your drawing, you want to copy their movements which might sound weird but a good way to get use to it is use a singular line to demonstrate the leg being straight, or two lines to show a bend in the elbow or knee.
Paper is just a means for you to get better don't be afraid to use all of your paper for 2-4 gestures, go out and buy a 500 Count copy paper stack for $7-10 and use the full paper. This is all for you to gain experience and you don't want to stay drawing small.
A big one that helped me is learning to hold your pencil in a grip that forces you to use your whole shoulder; so overhand Getting use to over-hand grip . This can allow you to do blunt broad strokes that can start pushing you into looser strokes. Only drawback is that using your shoulder feels wrong and hard to do when you start using it at first but it becomes so natural overtime and beneficial for so much more.
You will get frustrated. I should know, I started off my gestures as the same as yours wondering, "why do they look so round?", "What am i doing wrong?", or "i'm ass" but the way i got past it was by looking at gestures on this site or 30 second gesture videos that were better than me and just analyzing why they use certain lines, draw with them, and then practice on my own.
Get a feel for using less lines to draw with (example: using one line to show the back and a leg being straight. Or using one line to show an arm being extended in the air going down the back to a curved leg)
This is all that helped me but we are all different and find usually only certain part of tips to be most beneficial.
Experiment and have fun!
