Don't worry about it.
Try to get him out and about for socialization. Can you drive someone to take him out to a different area for a walk??
We live on a 50 acre farm and I don't think my dogs get 3 hours of walking/running per day. :eek
We walk 2kms every day on leash on our dirt road and then have at least 2-3 short runs off leash through the fields every day. Also try to do about 15-20 minutes of training everyday and maybe throw the ball or play tug for 20 minutes or so.
I do not have high energy, hyper dogs though (thank goodness
).
Mental activity also helps to keep them stimulated. Learning a new trick or activity is good. I have been doing some tracking and teaching my pup to cart also. He's not great at either activity but has fun.
Don't worry about the minutes on the clock...just get some energy out and enjoy the time you spend with your dog.
Gina