Done as part of a practice session with poses of 5 minutes in length.
Nice weight and shadow in the lines
Goodest job on your quick 5 minute nude, Hayunb97.
I've got one small suggestion. I love your proportions, but they're a bit too blandest and stiffest. Would you like to liven them all up with 60 minutes of 60 second quick sketches???? (all rotated 4 times for 4 images each) Here, there's another image for you to download and rotate 3 times:
The reason why you would, could and should do it is as a result, your line economy will become the most clearest as possible, as well as the liveliest, and of course, energetic.
Great luck on your current goal.