Head to the milk aisle. (Spencer Platt/Getty Images)

No gluten, no meat, no dairy: You know the story. The don’t-eat-any-foods-from-your-childhood diet has been in vogue for a while now, but one “bad guy” seems to be making a comeback, at least among athletes: milk.

“I think it’s great. Chocolate milk has a lot of benefits for muscle recovery,” says Ingrid Nelson, a personal trainer in the District. “It helps replenish the muscle tissue and actually gives you a shorter recovery time.”

So, chocolate milk over regular milk? Both are good choices unless they cause digestive issues, says Rebecca Scritchfield, a D.C. nutritionist.

But flavored milk — be it chocolate, strawberry or vanilla — has a more beneficial ratio of carbohydrates to protein for muscle recovery and rebuilding, Scritchfield says.

In other words, there is nothing magical about the cacao itself in chocolate milk; it’s the extra carbs — the sugars — that create the perfect potion.

Try chocolate milk after a workout. (PR NEWSWIRE)

“Milk alone may not be enough carbs or calories, but it can be enhanced to be adequate,” Scritchfield says.

The ratio to aim for is 4 grams of carbohydrates to 1 gram of protein, according to Joel Stager, professor of kinesiology at Indiana University and the author of several research papers on milk as a recovery drink for sports performance.

Nelson says that immediately on entering the body, milk creates spikes in insulin (in this case, these are good for you) that help transport sugar into the muscle, where it becomes glycogen. It also stimulates muscle protein repair and growth.

The amount of carb-infused milk recommended can range anywhere from 8 to 16 ounces depending on the intensity, frequency and duration of the exercise as well as the person’s gender, size and age.

So, let’s do the math on milk vs. flavored milk to reach the right 4:1 ratio.

An eight-ounce glass of 2 percent milk has 12 grams of carbohydrates and 8 grams of protein. Nowhere near the recommended 4:1 ratio.

That means — should you choose to make your own post-exercise milk drink — you would need to add about 20 grams of carbohydrates. For example, a small banana has about 20 grams of carbs. Voila! There is your flavored post-exercise sports drink.

Speaking of which, why not just buy Muscle Milk or one of the other sports drinks?

“Why not go with the real thing instead of the designer product?” responds Stager, adding that milk offers a host of other nutrients. These include electrolytes — important for hydration — as well as calcium, magnesium and vitamins A, D and B.

Not only that: When you start looking at the labels, you’ll notice that many of the designer sports drinks don’t have the the 4:1 ratio. A 14-ounce container of Muscle Milk, for example, has 25 grams of protein and only 11 grams of carbohydrates.

And then there is the price.

Let’s say you made your own carb-infused milk sports drink: about 25 cents for the eight ounces of milk (probably non-organic at that price) and another 25 cents for the banana. That would be total of 50 cents. (Another way to infuse milk with carbs would be to add 1.5 tablespoons of maple syrup.)

A commercial sports drink would run you up to 10 times that amount.

At the other end of the 4:1 ratio spectrum are the non-dairy milks such as rice milk and almond milk. They are great on certain nutrients but low — 1 or 2 grams — on protein.

Dairy might not work for you digestively. Many Americans suffer from lactose intolerance, and others feel icky and bloated when they consume dairy. Others are vegan.

For these people, Scritchfield suggests timing the workout so they can have a well-balanced meal afterward and skip that post-exercise recovery drink.

Just remember that milk — along with the carbs and the protein — is also a great way to hydrate because of its sodium and potassium levels. So add hydration to the post-exercise meal or snack.

Which brings us to the all-important timing for the best muscle recovery.

“Quickly after the exercise. First 30 to 45 minutes is the window of opportunity,” Stager says.

Nelson calls it “the power hour” — the window when the muscles are most receptive to sugar and protein in order to rebuild, Nelson says.

Milk protein consists of whey and casein, both of which help muscle rebuilding but in different ways. The whey is fast-acting, and the casein is slow-acting, Nelson says.

The amount of milk recommended can be anywhere from one to two cups, depending on the size of the individual and the type of activity, Nelson says. Same goes for the fat content. It depends on duration, frequency and intensity along with age and gender, Stager says.

For an elite athlete, whole milk might be preferable, while a middle-aged weekend warrior might do better with skim or 2 percent.

Also, says Scritchfield, if you’re exercising for less than an hour at a low to moderate level (such as low-key yoga), you’re probably fine with just water and your regular healthful meals and snacks. “Recovery is most important for intense workouts lasting longer than 60 minutes — think endurance and intense team sports.”

In the end, it seems milk has made a legitimate bad-guy/good-guy turnabout, if not among the general population, then at least among fitness folk. And who doesn’t like a good comeback story?”

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