1. Chocolate milk is the best food for recovery

Recent science has shown that low-fat chocolate milk provides the ideal ratio of carbohydrates and protein to boost fuel replenishment after exercise. In one especially noteworthy experiment, athletes who drank chocolate milk after a workout not only recovered more fully than those who drank a sugary sports drink or water, but they also gained more muscle, lost more fat and developed greater endurance capacity.

2. Beer actually helps boost immunity

Researchers at the Technical University of Munich approached runners who were training for the Munich Marathon and asked if they would—in the name of science—drink lots of beer. Hundreds agreed, even when told that the beverage would be nonalcoholic, and in some cases, a flavored placebo. The runners downed at least a liter of their assigned beverage every day. After the marathon, those drinking the non-alcoholic beer reported far fewer colds and other illnesses than the runners swallowing the placebo and had other indications of better immune system health.

The beneficial effects seem to result from the beverage’s rich bouquet of polyphenols, a substance that is known to fight off viruses, Dr. Scherr says. Of course, alcoholic beer is drenched in polyphenols, too—“even more than nonalcoholic beer,” he says—but has the signal disadvantage of being alcoholic. “We do not know whether the side effects of alcoholic beer would cancel out the positive effects caused by the polyphenols,” he says.

3. Loading up on carbs will make you slow and fat.

Not long ago, physiologists at the Australian Institute of Sport and several other institutions systematically tested the concept of carbo-loading. The researchers assigned trained male cyclists to either a carbohydrate-rich diet or a placebo version—one that was, essentially, the riders’ usual diet, but with the addition of a sweet shake that the riders thought was filled with sugary carbohydrates but which actually was sugar-free—the results were a surprise. There were no statistical differences in the two groups’ performances on a series of subsequent time trials, as long as both groups had access to sports drinks with carbohydrates in them. In that case, the cyclists’ bodies preferentially burned the calories from the sports drinks, leaving any stored carbohydrates untouched. The carbo-loading had been unnecessary. But it had almost certainly left the carbo-loaded riders fat. Stored carbohydrates pull water into muscle cells. The resulting weight gain may be temporary, mostly a few pounds of water weight, but it’ll be present during whatever event you’re carbo-loading for. Those enormous servings of pasta can’t ensure that you’ll be a better marathoner, but they can make you a heftier one. There is no such thing as a free lunch in sports nutrition.

4. Static stretching before a workout doesn’t prevent injury.

Most of us learned how to warm up in grade school, by touching our toes and slowly stretching our muscles, and haven’t changed our routines much since. Science, however, has moved on. In the past decade, a growing number of studies have shown that static stretching not only does not prepare muscles for activity, it almost certainly does the reverse. In a representative experiment conducted a few years ago at the University of Nevada, Las Vegas, athletes generated less force from their leg muscles after static stretching than they did after not stretching. In a few key, real-world studies, basketball players who stretched before a game were unable to jump as high during play as when they hadn’t stretched.

Of course, many of us might accept a temporary reduction in performance, if stretching protected us against injuries, as many of us have long believed that it must. But in multiple, large-scale studies of military recruits during basic training, stretching before long marches and runs did not lessen the incidence of overuse injuries. In the largest of these studies, results showed that an almost equal number of soldiers developed lower-limb injuries (shin splints, stress fractures, etc.), regardless of whether they had performed static stretches before training sessions. Similarly, in the largest study to date of everyday athletes who stretched, almost 1,400 recreational runners, aged from 13 to past 60, showed no difference in the rate of injury between those who stretched beforehand and those who did not.

5. You can compete well into (and past) retirement.

A recent study of participation at the New York City Marathon showed that the number of male racers in their 50s jumped by a remarkable 78 percent in the past thirty years and participation by female masters marathoners has swelled by more than 30 percent. During those years, the average finishing time for younger runners increased by almost 30 minutes—meaning the kids were getting slower. But the typical finishing time for older runners fell. The 70-plus men shaved nearly two minutes from their average time and the 60-plus women dropped their average finishing time by twice that.

Even more remarkably, during those same years, masters participation in the grueling Hawaii Ironman began to climb. The Ironman race, as you may know, consists of a 2.4-mile ocean swim, 112 miles of cycling, and a full marathon. Far more physically taxing than a mere marathon, the race had, at its inception three decades ago, no category for racers past 60. Now that age group and beyond are well-represented, especially among men. In fact, a few 90 year olds have finished the race.