There is a sentence that gets repeated in every dog forum: a tired dog is a good dog. It is true, and it sends people down a path that does not work. They walk further. They buy a ball launcher. They run the dog for an hour every morning and wonder why they are bouncing off the walls by six in the evening.
The problem is that physical exercise trains itself away. Everything else does not.
Why running them more backfires
Fitness is adaptive. Run a young dog an hour a day and within a few weeks they can run an hour a day comfortably, so you need ninety minutes to get the same effect. Keep going and you have built an athlete who is genuinely miserable on the days you cannot deliver. People who chase this end up trapped by a schedule they set themselves.
Ball launchers make it worse in a specific way. Repetitive high speed sprinting with hard stops is rough on joints, and the adrenaline it produces can leave a dog wired rather than settled. The dog looks exhausted and is still not calm. If your dog loves fetch, there are easy ways to make it kinder on their joints in is playing ball bad for dogs.
What actually settles a dog
Three things tire a dog in a way that sticks, and none of them is distance. All three are forms of enrichment, which is the umbrella term for the whole approach.
Sniffing. Scent takes up a huge share of a dog's brain, and using it properly is hard work. A walk where your dog is allowed to stop and investigate is worth more than double the distance covered at a march. Ten minutes on a snuffle mat settles many dogs the way a forty minute walk does.
Problem solving. Working out how to get food out of something is genuinely taxing. Watch a dog after fifteen minutes on a decent puzzle and they usually go and lie down.
Chewing and licking. Both are self soothing behaviors that lower arousal. This is why a chew works after a stressful afternoon when a walk does not.
The chase instinct still needs an outlet
None of the above covers the urge to run after something that is moving away. In a lot of dogs, especially terriers, herding breeds and anything with retriever in it, that urge is the loudest one, and it is the reason a dog who has just had a puzzle still brings you a ball ten minutes later.
You do not need to throw it for an hour. You need the ball to keep moving on its own so the chase lasts longer than your arm does. A self rolling ball changes direction and comes back, which gives a dog the unpredictability they are actually chasing. The whole range of interactive balls does the same job in different ways, and a gravity ball that hops sideways holds attention longest in dogs who get bored of a straight roll.
A day that works better than a long walk
Twenty minutes outside in the morning where they set the pace and sniff what they want. Breakfast out of a puzzle instead of a bowl. Five minutes of training at lunch. A chase in the afternoon. A chew in the evening. That is roughly forty five minutes of your time, spread out, and it settles most dogs better than a solid hour of walking does.
Puppies are a separate case
Do not try to tire a puppy out with exercise. Growth plates are still open and repetitive running can do lasting damage. The rough guide is five minutes of formal walking per month of age, twice a day, so a four month old puppy gets twenty minutes at a time.
Everything else on this list is safe and works better anyway. A puppy who is crashing around at seven in the evening is usually overtired rather than underexercised, and what they need is a chew and a nap, not another lap of the block. Small breeds have their own version of this problem, covered in toys for small dogs.
If nothing settles them
A dog who cannot rest even after a full day is worth looking at more closely. Some breeds were built to work all day and will not switch off without a job. Some dogs never learned how to be bored and need to be taught to settle, which is a training problem rather than an energy one. And a dog who paces, pants and cannot lie down may be in pain or anxious rather than under exercised. More exercise will not fix any of those three.