STEP 1: Get Fido Fit
You wouldn't drag an untrained spouse out for a five-mile run right off the couch—right? And you shouldn't throw your beloved goldendoodle into the fire, either. Though your dog was probably born to run fast, you need to start slow. Here's how to get rolling.

Don't start too young
Puppies shouldn't run with you until their bones stop growing, since their joints are prone to injury. This takes about nine months in small dogs, while large breeds may grow for up to 16 months.

Easy boy
Before you start, assess your dog's health and fitness status. If Bowser is overweight or severely out of shape, begin by walking. If you just adopted him from the pound, take him out for some easy strolls to assess his energy and fitness levels.

Don't go long...
You want to ramp up slowly, just like you did when you began running. "Start with three times per week for 15 or 20 minutes, and build up from there, adding five minutes each week," says JT Clough, a professional dog trainer and coauthor of 5K Training Guide: Running with Dogs.

...Or hard
"Just like us, dogs need a five-minute warmup before they run," says Clough. Look for signs of fatigue—flattened ears, tail down, heavy panting, and hind legs dragging. If the dog is exhausted, he may sit down and refuse to continue—a sure sign you've gone too far or too fast. And if he's really lethargic postrun, he might need a day or two off.

STEP 2: Teach Rex the Ropes
Runners may assume they can haul their dog along on a run, and the animal will just know what to do. If that works for you, thank your lucky stars, but dogs can be confused, crazy, even dangerous on a run if you can't control them. Here's how.

Use a leash
A gentle tug lets you guide Fifi's body and attention where you want it. "The dog needs to learn that it can't stop to pee every five yards," says Robert Gillette, D.V.M., director of Auburn University's Veterinary Sports Medicine program.

Play nice
You want the dog to be within three feet of you, to one side. Reinforce good behavior with a small treat or praise. Eventually the dog will see that the run is the real reward.

Be the pack leader
"The dog needs to understand that this isn't pure playtime, it's exercise time," says Gillette. Begin training sessions with laps of a short route—to reinforce behavior in a familiar environment and avoid getting stranded with a dog who's misbehaving.

Teach courtesy
If you encounter strangers on a trail, pull off to the side to let them pass without interacting with your dog. Remember, no one loves your dog as much as you, so don't assume others want your dog to greet them.

Pick it up
No one wants to step on poop during a run or hike. Have a plan and proper gear for disposal. (And, no, leaving a stinky bag under a bush doesn't count.)