When it comes to choosing your next running [life] partner, there are plenty of things to consider.  All dogs love to get their sprint on at the dog park, but the right partner depends on your running style, length, age, location, and frequency.

Running Length & Style

If your idea of a run is a 10 mile trek down to the next town and back, then you want an endurance partner...you need
 a young dog that's capable of endurance running.  With their medium build, long noses, muscular hind legs, and short sleek coats, the German Shorthaired Pointer, Goldendoodle, Jack Russel Terriers, Weimaraners, and Vizslas are your best bet.  If you're in mild or cold weather, you can't go wrong with the Kings of the Iditarod - the Siberian Huskies and/or the Alaskan Malamutes.  

If you're someone like myself who prefers to know out a quick 2-3 mile run, you also want a muscular dog, but don't need the marathon DNA.  The ideal dogs for the shorter distances are the Beagle, English Setters, Golden & Labrador retrievers, Greyhounds, and Pit Bulls.  

Age

Although puppies seem like a furry pile of never-ending energy, it's not recommended to begin running your dog before 7 months.  Dogs must reach skeletal maturity in order for their bones to support their muscles.  If the muscles tire and can not support the bones, the puppy soon begins grinding bone on bone, which ultimately may retard their growth and cause other health issues.  For most dogs this skeletal maturity occurs within their first year, although for some of the more enormous breeds, it doesn't happen until closer to the age of 20 months.  

Likewise, if you have an older dog, exercising them too much may cause muscle and/or joint strain.   

Frequency

Like age and running length, the frequency at which you run can certainly have an impact on your dog.  If you run one 5 miler a week and your dog is in good health, you're probably fine with any of the running dogs named above.  If you run 5 of those per week, you probably want to hone in on one of the endurance breeds.  

Location

If you live below the Mason-Dixon line and are poised to get your jog in (God bless you), then you want to make sure your dogs doesn't dehydrate and overheat.  Airedale Terriers, Fox Terriers, and Rhodesian Ridgebacks are all great dogs that can withstand the heat.  

If you're running in upstate New York over Christmas, you want a long hair dog that can withstand the colder temperatures.  German Shepherds, Alaskan Malamutes, Swiss Mountain Dogs, or Siberian Huskies are all great at running in sub freezing temperatures. 

All dogs love a great run, but choosing one that fits your lifestyle can maximize the health, safety, and pleasure of each of your runs.  For more info on the best dogs to run with see the illustration below.