Labrador Retriever board and train in Gloucester, MA

The AKC breed page rates the Labrador Retriever five out of five for energy, for playfulness and for trainability, and describes a friendly, outgoing, high-spirited dog of 55 to 80 pounds. It also warns that a Lab short on daily exercise is likely to turn hyperactive or destructive to burn off what is pent up. In training terms that is a willing student with a large engine, and the engine needs fuel before the lessons stick.

Retrieving is the breed's original job, and it shows in the mouth. Young Labs grab sleeves, leashes and hands, nearly always in play. The ASPCA notes that adult dogs who still mouth people probably never learned not to as puppies, and that time-outs work well for adolescents and adults. A year-old Lab that still grabs is not being bad; nobody has yet shown it a better place to put its jaws.

Then there is food. A 2016 study in Cell Metabolism found a deletion in the POMC gene in Labradors, at an allele frequency of 12 percent, linked to higher body weight and greater food motivation, and more common in Labs chosen as assistance dogs. Not every Lab carries it, but appetite is one reason the breed works so readily for kibble, and why its rewards should come out of the daily ration.

Gloucester's beaches are the obvious test, and the city's calendar decides when you can run it. At the time of writing, dogs may be off leash at Good Harbor on even-numbered days from October 1 to March 31 and at Wingaersheek on odd-numbered days from October 1 to April 30, and both are closed to dogs through the summer. Check the city's beach page before each season, since the rules can change.

The trick with a Lab is to stop the recall meaning the fun is over. Call the dog away from the water, reward it, then send it straight back in with a release word, so coming to you becomes the price of the next swim. A long line clipped to a harness keeps a lunge at a gull from wrenching the neck. This is practice for you after pick-up; where a stay's outings happen is set in the training plan.

Foundation ends with a go-home lesson and Advanced with two scheduled coaching lessons, all at Dogtown, where you practice the trades, the leave it and the recall while the trainer coaches your timing. Copy the shape of the stay at home: a short training game before breakfast paid from the meal, a sniff walk, a retrieve session with a sit between throws, and quiet chew time afterward. A Lab that works for its food twice a day has less reason to hunt the counter.

When the beaches close to dogs for the summer, the fenced Gloucester Dog Park at Stage Fort Park, with its separate large-dog area, keeps a recall in practice. Dogtown Academy, $89 a full day or $69 a half, puts a trainer into a play day; Canine Campus runs 2, 4 or 6 weeks of day training; private sessions start from $94. From Rockport, Gloucester, Essex or Manchester-by-the-Sea, the Pup Van brings your Lab in for $10 each way.