Amount of play time

Question
I was just wondering about the amount of exercise/play time that is recommended for my dogs. I have 3 pitbull/mix dogs.  One is 2-1/2 years old and the other two are now 2 years old.  Right now I give them about an 1-1/2 to 2 hours of play time in the morning (6a-8a)and about 4 hours in the afternoon (230p-6:30p).  With the bad economy, I need to put in more hours at work and was hoping to cut down on their play time, but don't want to hurt them in the process and/or wake up to damages.  Their play time consists of them just running around and playing with each other in a fenced yard 32'x 58'.  After play time they get put in their separate kennels to sleep or chew as they chew.  Any suggestions?

Answer
Hello Vicky;
I am travelling...you sound like a great owner!!! I think your program sounds great...if anything you are a model for others to follow.
I really cannot give you much more than a great going gal...as these dogs are going to chew, but, great toys, tugs, and bones are the best to give them, to keep them busy!
The Ball throwing if they like that after you get home is a great diversion as well.
Let me know if there is anything else I can do for you!
Best regards, and than you for your question...
If you have to cut their time, it won't hurt them, just love them more when you get home!!
Sincerely,
Melissa