So this is what your new Dolphins starting running back is doing while much of the NFL vacations:

Running. Lifting. Squatting. Sled-pulling. Pushing to validate every ounce of faith the Dolphins have placed in their gifted young back.

What makes the monotonous grind more pleasurable for Lamar Miller is that he is doing it alongside his friend and fellow Hurricane, Frank Gore.

“The way Lamar is learning from Frank, it’s a beautiful thing,” Steelers linebacker Sean Spence, another former Cane, said this week.

Gore’s mentoring of Miller has been one of the neater Dolphins-flavored stories of the summer, the four-time Pro Bowler and 49ers star taking the second-year protege under his wing. They work out together twice a day – with a group of other NFL players in the morning in North Miami Beach, and just the two of them, with a trainer, on a Davie field at night.

“Since Lamar started gravitating toward Frank, his work ethic and mentality are unparalleled,” said Pete Bommarito, who runs the highly-regarded Bommarito Performance Systems, where Gore, Miller and many other NFL players train during offseason mornings.

Miller, who almost assuredly will replace Detroit-bound Reggie Bush as Miami’s starter, began spending a lot of time around Gore a couple of months ago, at the suggestion of their agent, Drew Rosenhaus. Bommarito said Gore helped show Miller “how to take care of his body, what to do beyond what is required.”

Gore has noticed another change since they became workout buddies: “His footwork got a lot better."

Privately, the Dolphins believe Miller can be not merely a good starting back, but a great one.