Do you really have a reward?
A reward is something your dog is driven to obtain. Many things can be used as a reward but food is one of the most common and most misunderstood rewards. When a person gives their dog a treat to reward correct behavior the dog may eat the food but if the dog then turns it back on the owner instead of seeking out more food, it is questionable whether that particular food is a reward under the circumstances. Ideally when you give a food reward your dog will continue to pay attention to your in hopes of getting more rewards.
The only food reward I recommend a dog gets while it is at home under non-distracting circumstances is the measured portion of the dog's meal. I reserve all valuable treats to use when there are distractions or the dog is out in public. This helps keep the treats as a more valuable reward in the dog's mind. Because a food reward might be valuable under one set of circumstances but not under another, owners need to experiment to see what food rewards will work when their dog is in a novel environment or distracted with people, other dogs, wildlife, etc.
Luckily we do not have to limit ourselves to food rewards. There are a lot of other things dogs are driven to obtain. You can use play, social rewards and things in the environment to reward your dog's behavior. The key is you have to get to know your dog and what it will be driven to obtain under the circumstances. Once you know what your dog values, training becomes much easier, successful and fun.