How Long Is Too Long to Crate a Dog?

I am single and work 8-10 hours a day. I have a labrador-grayhound mix that is almost a year old. he behaives when I am home, but if I leave him alone out of his crate for even 15 minutes I will come back to disaster, like chewing on the walls. I give him plenty if chew toys and replace them when they are destroyed (usually within a day.) I am considering finding him a home where he will get more attention and won't have to be crated while I am at work. I take him on long walks when I can and let him run around at the park across the street. this dog can go 5 miles running with a bike and he will STIll have energy
Any advice for what I could do to keep him from dsstroying my apartmant when I'm gone so thay I can keep my baby boy would be very appreciated!!!!!

Excessive Home Dog Crating is perhaps the biggest abuse of dogs today, and the irony is, usually owners don’t start out wanting to crate their dogs for 8, 10 or even 18 hours per day. More commonly they are told by some trainer or other dog "expert" that crating is the only behavioral solution for problems ranging from housetraining to separation anxiety. But the fact is, too much crate time makes almost every canine problem worse. Compelling scientific research proves, time and time again, that excessive confinement, especially when combined with lack of adequate stimulation in pups' formative weeks, leads to some of the most serious behavior problems and prevents dogs from manifesting as the ideal companions we want. My husband and I have done extensive research for our book "Caged Love: Suburban Dogs and the Crate Training Conspiracy". Our own clinical experience, and much expert data, shows that dogs excessively crated in their families' living rooms can suffer the same kind emotional and behavioral symptoms as puppy mill victims. Without realizing it, owners who crate their dogs or young puppies when they commute to work plus all night have already confined their dogs 18 hours per day. If they crate a few more hours here and there when the dog acts "rowdy", their dog may spend 23 hours in a 24 hour period in a cage where he can hardly move around! Unfortunately crate times like this are not uncommon, even if owners let their dogs outside for 10 minute potty breaks or walk them briefly. Concerned dog owners who go to our Facebook page under "Caged Love: Suburban Dogs and the Crate Training Conspiracy" can check the discussion board to find a full list of 115 symptoms caused by excessive crating copied from the book. The list includes fears, physical symptoms, social difficulties and failure to bond properly with people. Don't be surprised if your dog shows some of the symptoms on the list, because they are especially common in dogs that originally came from pet store/puppy mill environments. When we rehabilitate excessively crated dogs in customers' homes, we slowly integrate them back into the real world teaching them to respond to new stimuli without fear, aggression or overexcitation and to look to their owners for guidance and feedback. Dogs are bred to work beside humans, and it's natural for them to want to support us and be with us in daily life. And many of our customers found that when they tried some of the enjoyable games and bonding activities in our first book, "The Cure for Useless Dog Syndrome" their dogs’ behavior improved. Most owners love their dogs and don't really want to lock them up. So it's a shame when "experts" in the dog industry prescribe caging dogs as a cure-all for our societal malady of too little time. Instead, we need more positive ideas to help dogs and their owners master the challenges of the modern world together...