By Christopher Mohr
Christopher Mohr, MS, RD, LDN, is a doctoral candidate in Exercise Physiology at the University of Pittsburgh. He is a registered and licensed dietitian and was a Sports Nutritionist at the University of Massachusetts for two years.
Training & Conditioning, 14.9, December 2004, http://www.momentummedia.com/articles/tc/tc1409/tomatoaday.htm
Staying up to date on the latest recommendations in sports nutrition is no easy task. But it is easier thanks to a special one-day symposium now held annually in October to kick off the American Dietetic Association conference.
Organized by the Sports, Cardiovascular, and Wellness Nutritionists (SCAN) group, this year’s meeting was titled "Nutrition Counseling for Athletes: Different Sports, Different Approaches." This article is a summary of the seminars most applicable to those of us working with high school and college athletes.
Emerging Research on Exercise & Immunity: Can Nutrition Make a Difference?
Presented by David Nieman, DrPH
To ensure they are prepared for competition, most athletes focus on sport-specific training, resistance training, and cardiovascular work. But one aspect of preparation that athletes often forget is "training" their immune system. Athletes who are unable to compete because of illness are obviously not maximizing their contribution to the team.
Studies have shown that athletes who exercise excessively may have weakened or impaired immune systems because of the additional stress they encounter. In fact, one study by Nieman and his colleagues demonstrated that nearly 25 percent of runners reported an infection of the upper respiratory tract in the immediate two-week period following an ultramarathon (100-mile run). Of course a 100-mile run is an extreme case, but another study published in the late 1980’s demonstrated that even after a marathon (26.2 miles), there was approximately six times the number of upper respiratory tract infections among the athletes than there were in the control group of non-athletes.
In addition, college students don’t always get enough sleep and live in close quarters that expose them to a high concentration of germs. Therefore, finding ways to strengthen the immune system is important for your athletes. But can one enhance his or her immune system through nutrition?
To fight off getting sick, many athletes turn to antioxidant supplements along with taking other vitamins and minerals. In a study published in 2002, researchers measured the effect of supplementing with vitamin C. The researchers provided either vitamin C or a placebo to the athletes in a 20-mile race. The authors found no significant changes in immune function in the body.
Similarly, vitamin E is another common antioxidant supplement used to boost immunity. In a recent study, athletes were provided either vitamin E or a placebo during an Ironman triathlon. Again, the athletes supplemented with vitamin E had no significant immunity benefits after the race.
Next, Nieman reviewed several published studies that measured the effects of carbohydrate on immune changes during heavy exertion, with some promising results. In these studies, athletes supplemented with a sport drink containing carbohydrate, which was found to positively enhance their immune systems. In addition, the authors found that during activity with rest intervals, immune markers were not negatively impacted to the same degree as they were during long, continuous activities.
Nieman suggests supplementing with carbohydrate drinks or gels during rest intervals in training or competing. He also recommends introducing rest intervals if exercise duration exceeds 90 minutes. However, more research is necessary on the effects of other dietary supplements, such as protein, glutamine, other antioxidants, and other nutrient mixtures.
Weight Class Sports: How to Lose Pounds Safely
Presented by Amy Freel, MS, RD
Helping wrestling athletes with nutrition can be one of the toughest challenges coaches, athletic trainers, and sports nutritionists face.
The practice of "making your weight" has a long history of unhealthy methods that wrestlers are only just beginning to face.
In this case study, Freel described a college wrestler who competed at 141 pounds but constantly struggled to make weight. After he gained 30 pounds during the off-season, his coaches decided to move him up a weight class. However, his new weight of 170 pounds was still a far cry from the 149 pounds needed to make the new class.
Because the tradition in wrestling is to lose weight by starving oneself and sweating out extra pounds, Freel felt it was important to clarify that these practices are dangerous and do not ultimately improve performance. Even though new rules in the sport are helping curtail rapid weight loss practices, there is still much education that needs to be done.
When counseling the wrestler, Freel emphasized how rapid weight loss and dehydration will negatively affect performance—that without the proper fuel and a hydrated body, he will not have the energy to perform at his best. She also explained that losing weight slowly will pay off in the long run, since the weight is more likely to stay off, and that fasting or starving can actually slow metabolism.
In addition, Freel talked to the coaches and athlete about focusing on body composition rather than body weight. She explained that a leaner athlete is better than a skinny athlete with lower lean body mass. Although it flies in the face of tradition, it would be much better for wrestlers to move up a class than to lose enormous amounts of weight to make unrealistic goals.
Freel also provided a specific list of suggestions:
• Do not starve yourself.
• Eat small snacks throughout the day.
• Eat nutrient-dense foods that are high in fiber, which help satiate and prevent overeating. Good examples are fruits, vegetables, and oatmeal.
• Stay hydrated by drinking at least 16 ounces of fluid for each pound of weight lost during practice.
• Eat carbohydrate, which is the main source of fuel for explosive and powerful sports such as wrestling.
• Do not allow your weight to fluctuate more than five pounds from your class in or out of season.
Athletes and Protein: How Much & When?
Presented by Martin Gibala, PhD
With the popularity of low-carb, high protein diets, athletes are easily confused about how much protein they need. Gibala’s presentation reiterated information that many athletes still haven’t heard.
The first important reminder was exactly how much protein athletes need. Here is a general breakdown of the protein needs of individuals:
Sedentary individuals need 0.36 grams of protein per pound of bodyweight. A person weighing 155 pounds, for example, needs 56 grams of protein a day.
Endurance athletes need 0.64 grams of protein per pound of bodyweight. A person weighing 155 pounds needs 98 grams of protein a day.
Strength athletes need 0.77 grams of protein per pound of bodyweight. A person weighing 155 pounds needs 119 grams of protein a day.
Most athletes fit somewhere between the endurance and strength categories. As long as athletes are getting enough calories, they are probably getting plenty of protein.
The second important reminder was the need for a small amount of protein, with carbohydrate, immediately following a workout. Various studies have shown that 6 grams of essential amino acids plus 35 grams of simple carbohydrates can facilitate glycogen resynthesis and muscle accretion.
What type of protein is recommended after a workout? One recent study compared the effects of 18 grams of soy protein with the effects of 18 grams of milk (primarily casein protein) after resistance training. The results demonstrated that the acute stimulation of muscle protein was higher after milk than after soy protein.
I recommend using low-fat chocolate milk as an excellent, inexpensive way to rehydrate athletes after a workout. Because chocolate milk has more carbohydrates than plain milk, as well as the recommended amounts of carbohydrate and amino acids, it works well. Other suggestions include yogurt and yogurt smoothies, which are convenient, rapidly absorbable sources of nutrients.
The Football Athlete: Diet Makeover Needed
Presented by Leslie Bonci, MPH, RD, LDN
One of the hurdles sports nutritionists often face when working with athletes is the limited amount of time they have to provide the necessary information. Therefore, sometimes it is best to provide only the bare essentials necessary to keep the athlete healthy and performing well. This is especially true when an athlete’s diet needs a big overhaul.
In this case study, Bonci was working with a 300-pound offensive lineman at an NCAA Division I university who was told he would be a better player at 280 pounds. The athlete decided that the best way to lose weight was to eat only two meals per day and restrict carbohydrates. He also restricted his sodium intake, drank only a protein shake for dinner, and spent extra time doing aerobic work to burn more calories. He typically went out a few nights each week and drank several beers.
This player saw the dietitian because he was feeling fatigued during practice. Nutrient analysis revealed an intake of 2,300 calories per day, with only 50 grams of carbohydrate, 275 grams of protein, 50 grams of fat, and about 600 calories from alcohol alone.
The first consideration here was the extremely low caloric intake. The estimated needs for this player are approximately 5,600 calories per day. Bonci’s first message: Eat more.
It is crucial that the player increase his carbohydrate intake to eliminate fatigue during practice. This should come naturally with the increase in calories, but you can never assume anything when communicating with your athletes. Message number two: Eat more quality carbohydrates, including fruit, vegetables, pasta, and whole-grain bread.
Message number three: Beer does not count as a quality carbohydrate! Bonci explained to the athlete that he could lose the weight he wanted by simply cutting out alcohol from his diet. She also explained that alcohol consumption in the evening can affect one’s energy levels in practice the next afternoon.
Bonci emphasized the importance of staying hydrated. She explained that an athlete who is even marginally dehydrated can feel under par at practices and games. Message number four: Drink plenty of water—and a sports drink, if possible—during practices and games.
While a thorough diet analysis and specific suggestions on food choices would have provided this athlete with a more thorough plan, Bonci thought that the likelihood of this athlete following such a plan was remote. Therefore, she decided to provide him with four very clear, simple messages, all of which related to improving his performance. The tactic proved successful in helping the athlete lose weight, reduce fatigue, and begin a plan for healthier eating.
Fluid Needs for Athletes: Getting the Message Out
Presented by Stella Volpe, PhD, RD, FACSM
The importance of hydration for optimal performance is now well-known, as is the danger of dehydration in athletes. Research has demonstrated that losing as little as one percent of bodyweight from fluids (e.g., two pounds for someone who is 200 pounds) can negatively affect performance. And acute dehydration can lead to a number of consequences such as heat exhaustion, heat stroke, heat intolerance, cardiovascular strain, and impaired mental performance. In addition, chronic dehydration leads to many more negative health consequences, such as gall stones, kidney stones, and urinary tract infections.
The problem is that some athletes are not properly hydrated before walking onto the playing field. The solution: more clear-cut guidelines to athletes on proper hydration and more vigilance by athletic trainers.
Athletes need to understand what helps and hampers hydration. Volpe suggests providing athletes with these tips:
• Attach a full water bottle to your backpack and drink several swallows between each class.
• Have at least two glasses of water or non-caloric juice at every meal.
• Eliminate beverages that act as diuretics, such as alcohol.
• Count fruits and vegetables towards fluid consumption.
• Drink enough fluids to make your urine a pale yellow, not a concentrated gold color.
• Stay hydrated at all times. You can’t make up for a lack of fluids by hydrating only before practice or a game.
Athletic trainers should also consider weighing athletes before and after training, especially during extended practices in hot weather. For every pound of weight lost, athletes should rehydrate with 16 ounces of fluids.
To help reduce the risk of dehydration, water bottles should be available at all times during practices and games. During games, water should be forced upon athletes to ensure that dehydration doesn’t become a problem.
Athletic trainers need to remember that other factors play a role in hydration. For example, athletes who wear extensive padding, such as football or ice hockey players, will typically sweat more because of the additional weight and layers. Athletes who are continually running, such as soccer and basketball players, will need more fluids than more stationary athletes. Of course, climate also comes into play. Along with high temperatures, high humidity increases the risk of dehydration.
To learn more about Sports, Cardiovascular, and Wellness Nutritionists (SCAN), see: www.scandpg.org.
Take Home Messages
These are some of the most important points from the conference’s presentations:
• To boost immunity in athletes, carbohydrates may be important, but supplementing with vitamins C and E appears to be ineffective.
• During workouts that exceed 90 minutes, introducing rest intervals may boost immunity.
• Athletes in weight-class sports need specific suggestions for gradually losing weight.
• Athletes in weight-class sports should not deviate from their desired weight by more than five pounds in or out of season.
• Athletes needing to lose weight should eat small snacks throughout the day, consume fiber-dense foods, and stay hydrated at all times.
• Within one-half hour after a workout, athletes should supplement with a product containing at least 35 grams of carbohydrates and six grams of amino acids. This should be doubled for athletes over 150 pounds and tripled for those over 200 pounds.
• For rehydrating athletes after a workout, drinking milk protein appears to be more effective than drinking soy protein.
• Athletes who don’t have the time or interest to make drastic changes to their unhealthy diets need simple, clear-cut suggestions.
• Many athletes need to eat more carbohydrates.
• Many athletes need more information on how to stay hydrated.
• For every pound of weight lost during an event, athletes should rehydrate with at least 16 ounces of fluid.
• Athletes should be provided with fluids during events and encouraged to consume fluids throughout the day.