How to stop dog from digging?
I know it is because she is restless and I DO exercise her everyday as much as I can. But some days I REALLY don't have the time to do a full length run and can only play fetch in the back yard for 45 minutes. These are the days she digs, Is there any way to discipline her to stop digging?

Check out the Purina site (under dogs, behavior, biting, chewing & digging.
Don’t stop it. It is part of her prehistoric instinct when the dogs hunt for food. Let your dog does what it pleases except when it starts to tear some things to destruction. Give her playthings – - like balls, hard leather bones, your neighbor’s cat, whatever.
say to your dog NO
every time your dog tries to dig take your dog away from where (s)he was digging and also you can give your dog a sand box or a baby pool filled with sand so (s)he can dig without ruining your back yard
Get her a little mini sand pit, and bury toys. It encourages her to dig for the toys IN the sand pit, I heard it works.
No. She’s a dog. They dig.
THis may be a bit complicated, but with determination it could be done. Below are several ways to stop digging one or a combination of more should work. good luck