LOL
Mocha just finished doing this. She usually goes crazy with her toys like baby toys and my sister's bunny slippers (it's the perfect size for them, and it doesn't tear easily!), just RAVAGE those toys like she's a real tough dog, runs around with them, runs around some more, and falls asleep like she drops dead, usually right beside her pillows
I think it's totally normal. Mocha + Lulu does this when I have just showered them the day before and don't take them out (I want the baths to last at least a day lol), I think it's more like their way of getting their own exercise.