On that note some go wild and wear themselves down. Their sugars can drop as they are not used to so much activity being caged.
I do believe a couple of hours of free run would be very exhausting and could be very dangerous.
I left them playing in the laundry room one night to dart a few feet to the fridge. One shimmied up the side of the cage to the top, and jumped to the washer. After several days of trying steroid injections I had to put him down. His spine was injured and he was paralyzed from the waist down.
I have one that has had seizures from exhaustion, and just had a call last night from a lady who's chins seems to be suffering the same.
She told me he is usually out from 7:30-9:30 running around the house, but this night he was out from 5:30, went missing, and after being found suffered some kind of episode.
I recommended she not leave him out so long.
Keep on eye on her, don't let her over do it, and never take your eyes off her while she is out. They will and can get into anything.