I feel so sleepy and tired if I dont move

Sometimes when I don't exercise even for just one day (I usually do cardio cycling every single day, about 20-30 minutes), I end up having to sleep in the afternoon, even though I may have slept 9-10 hours during the night.

Besides this, I feel foggy, have much less desire to do things, and feel physically exhausted. I don't have any other health conditions, but still, when I skip daily exercise (often high-impact!), I feel like crap.

I don't know if this is normal or not.