Exercise also helps lower blood
sugar. Muscles need glucose
in order to function, and the two things which deliver that glucose
are insulin and adrenaline, and adrenaline is released during exercise.
As for sleeping late, that shouldn't have any direct effect on blood sugars. Getting a good night's sleep can make you feel better overall, though, and that positive influence can improve your mood, which can actually lower you blood sugars after you wake up.