The importance of adequate exercise cannot be stressed enough! Dogs need mental and physical stimulation to be healthy, happy, and relaxed. Especially young dogs and working breeds. A romp in the yard for a young dog is not enough.
An hour daily brisk walk (or two half hour walks) will help with bonding, leadership, and manners (some dogs will need more). "A tired dog is a good dog!" Throwing the ball or playing with other dogs can be very helpful, too. But nothing beats a good brisk walk or jog with a family member! Ironically, the dogs who need a walk the most often don't get it because they are out of control, pulling, lunging, and reactive. I love working with owners and their exhuberant dogs. It is so rewarding to help transform them to a calm, happy, confident walking or hiking companion.
If you work long days then you may want to hire a dog walker or consider a well supervised, clean dog day care a couple of days a week.