Is food the ultimate performance enhancer? More and more, athletes, nutrition experts and fitness buffs are saying yes!

Is food the ultimate performance enhancer? More and more, athletes, nutrition experts and fitness buffs are saying yes!

Track and field Olympian Marion Jones was America's darling during the 2000 Olympic games in Sydney, bringing home three gold medals and two bronzes. She ran like a lean, high-powered machine, and credited nutrition supplements-including flaxseed oil and iron-for her superstar performances. Later, she admitted to taking steroids. Since then, accusations of using performance-enhancing drugs have become frequent among elite athletes such as baseball pitcher Roger Clemens (who still denies using steroids and human growth hormone) and American cyclist Floyd Landis (who was stripped of his title as the 2006 Tour de France winner after blood tests suggested he took synthetic testosterone). As a result, most sports nutritionists won't recommend supplements-or even multivitamins in some cases. They're afraid that a tainted pill could cause an athlete to fail a drug test.

"The risk of product contamination can be as high as one in five or one in six," says Martin Gibala, Ph.D., associate professor in the department of kinesiology at McMaster University in Canada. Besides, "athletes need to eat real foods to enhance performance-not supplements," says Gibala. In fact, experts say, getting the right mix of carbohydrate, protein and fat can mean the difference between an Olympic gold medal in Beijing and going home empty-handed.

Carbohydrates for Going the Distance

Swimmer Erik Vendt took home silver medals in the 2000 and 2004 Olympics for the 400 meter individual medley and then retired, citing the stress of training. At the time, he loved junk food and would often have a midnight snack of candy or chips. Today he's back, ranked among the top 5 in the world and training for Beijing. "Nutrition has helped me tremendously, mostly by elevating my training level-and that has a direct impact on how much time I drop during my races," says the 27-year-old, who now eats an all-organic diet focused on whole foods. "Before a workout, I don't like to stuff myself with a meal; instead, I eat enough to give me the energy I need to attack the workout properly. I eat a bagel, fruit or a bowl of oatmeal."

Like many athletes, Vendt starts with carbohydrates. Since the 1920s, researchers have known that eating carbohydrates enhances performance. "We're still recommending carbohydrates to athletes and active individuals, but the amount depends on the sports, the individuals, and their weight and health goals," says Melinda Manore, Ph.D., a professor in the Department of Nutrition and Exercise Sciences at Oregon State University. Carbohydrates break down easily and quickly raise your blood sugar, which fuels your muscles and your brain.

Trouble is, while the body can store large amounts of protein (as muscle) and fat, it has a limited capacity to store carbohydrate. "The typical athlete can store between 400 and 600 grams of carbohydrate [or 1,600 to 2,400 calories] in the muscle as glycogen," says Nanna Meyer, Ph.D., R.D., a research associate at The Orthopedic Specialty Hospital (TOSH) who has worked with Apolo Anton Ohno and other members of the U.S. Olympic Speedskating Team as well as Olympic cycling champions. Because of this, endurance athletes, such as marathon runners, long-distance cyclists and cross-country skiers, can burn through their glycogen stores after about 90 to 120 minutes of exercise. Once glycogen is depleted, the body mobilizes fat, which muscles cannot burn at the same rate as carbohydrate. The resulting fatigue-also called "bonking" or "hitting the wall"-can be so debilitating, athletes can have difficulty moving.

To prevent bonking, long-distance athletes supplement with carbohydrates during a workout-literally, they eat on the run or the ride. Many athletes go straight for specially formulated sports gels or drinks, which provide easily digested simple carbohydrates and electrolytes, such as sodium and potassium (which are lost through perspiration), minerals that help the body maintain a healthy fluid balance and keep the heart working properly. Gels generally are easier to carry than high-carb "real foods," such as bananas or raisins (which contain potassium) or pretzels (which provide sodium). However, according to some nutrition experts, these specialized products aren't necessarily better at maximizing performance. For example, according to a small San Diego State University study (funded by the California Raisin Marketing Board), eating raisins prior to a workout was just as effective as consuming the same number of carbs in a sports gel.

That said, fueling up mid-workout is a science. The body can generally absorb only about 60 grams of carbohydrates, or 240 calories, an hour, says Gibala. If you eat too much, the carbohydrates aren't absorbed into the bloodstream and sent to muscles; they just stay in the digestive tract-so you can end up with a lot of cramping.

However, recently a lab in the UK found that a blend of fructose and glucose allows the body to burn up to 108 grams of carbs an hour (compared to 60 grams for straight glucose). Scientists found that when eight trained cyclists consumed glucose and fructose together throughout their workouts, they stored more energy in their muscles and, as a result, completed the course 8 percent faster than when they fueled up on straight glucose and 19 percent faster than when they sipped plain water.

"Chemicals in our digestive systems transport sugars from the stomach into the intestines and then into the blood. And those transporters respond differently to different types of sugars," says Gibala. "So giving multiple types of sugars allows the athlete to get more energy into their muscles to fuel the work." It's like having multiple doors to a stadium: with more doors, the stadium sections fill up faster.

Historically, carbs were the only nutrient for fueling up, but new research suggests that athletes may benefit from eating protein during a workout too. In fact, the latest craze in sports nutrition is spiking energy drinks with protein. A couple of studies on trained cyclists reported that when athletes consumed a drink containing about 2 percent protein (and the rest carbohydrate) they were able to cycle up to 30 percent longer than when they consumed a sports drink containing only carbohydrates. Despite the promising results, experts claim the research isn't conclusive, that the benefits may come simply from consuming more calories overall. "Basically they just added protein on top of carbohydrates," says Gibala. "So is it an effect of protein, or is it the fact that you're just giving people more calories?" No one knows for sure-and, from a biochemical standpoint, there's no generally accepted explanation for why consuming protein during exercise would improve performance.

Protein For Rebuilding and Repairing

What researchers do know about protein is that it's critical for recovery after intense exercise. Protein consists of 20 different amino acids-nine that are essential (meaning that we have to get them from food) and 11 that the body can produce. When athletes eat foods containing protein within a few hours of working out, their bodies make more protein than they break down. The result? They're repairing muscles that get torn up during high-intensity exercise, which means that, at the end of the day, they're maintaining-or even gaining-muscle.

"We don't know which amino acids are best, and there's certainly no evidence that any one protein-based product is better [for recovery] than another," says Gibala. "The message for athletes is that eating a food that provides some protein after a workout is going to be beneficial. Does it matter if you get it from a glass of chocolate milk or a tuna fish sandwich or a protein bar? Right now, we can't say, so our advice is just to eat real food when you can."

Sports nutrition experts recommend spreading small protein meals throughout the day since frequently consuming small doses helps the body convert amino acids from food into protein it can use to build new muscle.

"If you look at body builders, some of them intuitively eat every two to three hours to the point of waking up in the middle of the night to eat a small amount of protein," says Gibala. How small? Benefits come with as little as 6 grams of protein-that's what you'd get in an egg or a glass of milk. The recommended protein intake is 0.4 gram per pound of body weight for moderately active individuals and about 1 gram per pound if you lift like Arnold Schwarzenegger.

"Some of the recovery shakes have 50 grams of protein," says Meyer. "That's overkill; the body will not profit from that." In fact, the body will process excess protein as it does all extra calories: those not used will be stored as fat. Instead of overdoing it on protein, experts tell athletes to add complex carbs, such as vegetables and whole grains, to their post-workout meals. Scientists think that these healthful carbs may help the body absorb protein. Complex carbs also contain many essential vitamins and minerals that aid in recovery and muscle building, and they offer the body an alternate source of energy so it can reserve protein from the diet for muscle repair and growth.

Speedskater Chris Needham follows this advice. "I love eating a big juicy steak after a workout," he says, "But it's not like I'm going to the Texas Roadhouse and having a 42-ounce slab of meat. I eat a balanced meal with lots of fresh vegetables and some potatoes-something that covers all of the bases." Needham's strategy not only prevents protein overkill, it also limits his intake of saturated fat.

Healthy Fats to Curb Inflammation

Fat was one nutrient João Correia, 33, loved, but when he decided to go back to professional cycling after an 11-year sabbatical, he knew he needed a dramatic lifestyle change. As the associate publisher of Bicycling magazine, Correia's responsibilities frequently included entertaining clients. He was eating five- or six-course meals a few times a week and washing them down with several glasses of wine. "I come from a family of people in the restaurant business, and I love food. Some people take clients to games or sports events," says Correia. "I took them to eat."

But when one of Correia's clients suggested he drop his extra weight and get back into racing, Correia decided to give reaching the pro level a shot. It was a lofty goal, but it was just what Correia needed to get back into shape.

"In cycling, the lighter you are and the more power you can produce, the faster you're going to go," says Correia, who once rode for Portugal's national team. But at 5'9" and 185 pounds, he wasn't going very fast. By working with Meyer, Correia was not only able to drop 40 pounds, but he also learned how to fuel his body for optimal performance.

"Most cyclists don't think about nutrition-they're just focused on weight," says Correia. "But I view food as a big part of my competitive advantage. I learned a completely different way of eating that still allowed me to enjoy the foods I like."

Fat itself wasn't the problem. It was the type of fat Correia was eating. Loading up on steak with béarnaise sauce, fettuccine Alfredo and foie gras weighed him down and exacerbated the inflammation that accompanies high-intensity exercise. So Meyer revamped Correia's diet to replace inflammation-stoking saturated fats with healthful unsaturated fats. Instead of pasta Bolognese with ground beef and heavy cream, she gave Correia a recipe that uses lean ground turkey and olive oil. He peppered his diet with omega-3s from fish, and heart-healthy fats from avocados, nuts and olive oil. As a result, he lowered his calorie intake and boosted his energy levels.

When you measure how much fat and carbohydrates a person uses for energy, an elite-level athlete like Correia will always burn more fat than someone who exercises occasionally. The body naturally adapts to allow athletes to reserve carbohydrates for a quick energy boost at the end of a long workout, says Meyer: "The more trained an athlete becomes, the more fat they are able to store in the muscle and use for fuel. Part of that training adaptation allows them to store fat close to the muscle cell so it can be burned quickly." These intramuscular triglycerides-or intramuscular fats-enable athletes to use fat for energy as seamlessly as carbohydrates.

It worked for Correia. Healthful fats not only provided him with sustained energy in the form of intramuscular triglycerides but also made his food taste good and helped him feel satisfied on a lower-calorie diet. Correia claims his comeback at the pro level has been as much about nutrition as it is about training. Food can make or break your performance, he says-especially if you're carrying around extra pounds.

Correia's next goal is to win a medal at the National Championships in Portugal this summer. Even though he is one of the very few professional riders who also hold down full-time jobs, Correia knows he has a chance. After all, he stopped racing at the age of 21 and made a comeback a decade later. Now he races for a U.S. professional team (Bissell). Some might say that was an impossible goal.

-Amy Paturel, M.S., M.P.H., is a freelance writer in Seal Beach, California.

July/August 2008