Pulled an all nighter, and now my legs are extremely sore?

So i stayed up all night last night being productive and all, anyways my legs were really tired around 10 or so that night, and after a while i didn’t pay any attention to them.
I got in my bed at 7:30 this morning (didn’t actually fall asleep till 9 till 10) anyways, me legs HURT.. BAAAD!

They are extremely sore and it feels like i worked out, why are they in so much pain, anyone have an idea?