As a coach, you want to stay current on what can help and what may hinder your athletes. From youth soccer to coaching basketball and beyond, nutrition is obviously an important performance factor — and hot off the presses, the American College of Sports Medicine (ACSM), American Dietetic Association, and Dietitians of Canada have joined forces to publish an updated position statement on the topic of "Nutrition and Athletic Performance." This new position stand replaces their first effort, which was published almost 10 years ago. Here we review some of the highlights from the report to keep you in the know:
Know when not to push weight loss
Sometimes athletes need to lose weight or reduce body fat in order to achieve their performance potential. But weight loss has its time and place, and that place is not during periods of high-intensity, long-duration training. Make weight loss a goal of the off-season or before training gets hot and heavy. When your athletes are working long and hard, they need all their calories to stay healthy and to maximize the gains from their training. Pushing for weight loss on top of tough training can result in loss of muscle mass, slower recovery, and an increased chance of illness and injury. In addition, female athletes, who are more prone to inadequate calorie intakes, can suffer hormonal imbalances leading to menstrual dysfunction and permanent loss of bone mass and strength. Talk to your athletes and emphasize the right time to lose weight and the importance of adequate calories during heavy training.
Carbs are crucial
No matter which diet book is this year's bestseller, carbohydrates remain the dietary staple for athletes. During endurance exercise, muscles rely on fats and carbs for fuel. The more intense the exercise, the more carbohydrates are called to duty. For exercise of moderate to high intensity that could be sustained for 1–4 hours at a time, 50–60% of the energy fueling muscle contractions is coming from carbohydrates, and the rest from fat. Fat reserves we don't worry about — even very lean athletes have plenty of fat stored away — but carbohydrate stores are in much shorter supply. A couple of hours of intense exercise can substantially deplete or even exhaust glycogen fuel reserves. Daily carbohydrate needs are based on body weight, and recommendations for athletes range from about 2.7–4.5 grams carbs per lb (6–10 grams per kg) body weight. For a 150-lb (68-kg) athlete, that nets out at 405–675 grams of carbs each day. So spread the word that carbohydrates are king and that healthy sources include fruits, vegetables, whole grains, cereals, and beans.
Protein needs of endurance and strength athletes
Most endurance athletes require in the range of 0.5–0.64 grams of protein per lb (1.2–1.4 grams per kg) body weight daily. For a 150-lb (68-kg) athlete, this amounts to about 82–95 grams of protein daily. The majority of athletes get the protein they need. What they often don't get is the importance of consuming adequate calories and carbs along with protein. If your athletes are short on calories and carbs, they may be using the amino acids from the protein they eat as an energy source rather than for the making of new proteins to repair and build muscle tissue.
Strength-training athletes may need a bit more protein than their fellow endurance athletes: The recommended intake range is 0.5–0.8 grams per lb (1.2–1.7 grams per kg) body weight daily. For a 150-lb (68-kg) athlete, this equates to about 82–116 grams of protein daily. Here again, pairing protein with sufficient calories is crucial if muscle growth is the goal. A higher protein intake plus adequate calories is especially important early in strength training, when the largest gains in muscle mass are likely to occur.
Healthful protein sources include fish, poultry, lean meats, low-fat and nonfat dairy products, nuts, seeds, and beans. Vegetarian athletes relying solely on plant sources of protein may require additional protein. This is because certain plant protein sources, like some types of beans, are less digestible. The protein needs of vegetarian athletes are estimated to be about 0.6–0.82 grams per lb (1.3–1.8 grams per kg) body weight daily. For a 150-lb (68-kg) athlete, this nets out at about 88–122 grams of protein daily.
Hydration recommendations before and during exercise
Staying hydrated is crucial for athletes to perform at their best. Performance can be negatively affected by a 2% drop in body weight due to fluid loss during exercise. This is just 3 lbs (1.4 kg) in a 150-lb (68-kg) athlete — a fluid loss that is common during a long practice session or competition, especially in hot weather. Dehydration also increases the possibility of a potentially life-threatening heat stroke.
Dehydration can be prevented by encouraging athletes to hydrate before and during exercise. The new ACSM report recommends that athletes begin drinking fluids about 4 hours before a workout or competition. This helps to ensure adequate hydration, while allowing enough time for excess fluid to be excreted beforehand. A good pre-exercise hydration rule of thumb is to drink about 2 fl oz (60 ml) for every 25 lbs (11 kg) body weight.
During exercise, the hydration goal is to prevent a water loss of more than 2% of body weight. One-size-fits-all hydration plans are obsolete. State-of-the-science hydration calls for each athlete to have an individualized hydration protocol based on their own sweat rate. "Individualized" is key, because sweat rates can vary considerably between athletes and from one day to the next. PowerBar makes it easy for athletes to figure their sweat rates. In fact, for a step-by-step guide to calculate sweat rate and to obtain a personalized hydration plan, direct your athletes to the PowerBar
Sweat Rate Calculator at PowerBar.com. In addition, you may want to devote some time during early-season training to review with your athletes the importance of hydration and using sweat rate to guide fluid intake during exercise.
Sodium is part of the hydration equation
Sodium is the key electrolyte — dissolved mineral — found in sweat, and replacing it is important for maintaining your fluid and electrolyte balance. To help replace the sodium lost during exercise, ACSM recommends consuming a sports drink that contains sodium. Another option is to consume an energy gel that contains sodium and to pair it with water. Consuming sodium during exercise not only replaces some of the sodium being lost, it also stimulates the drive to take in more fluids and helps with the retention of the fluids consumed.
Eating before exercise makes a difference
Athletes who eat before a workout or competition generally perform better than those who go without. So encourage your athletes to eat a pre-exercise meal. The goal of the meal is to top off carbohydrate fuel stores and to ward off hunger, yet to do so in a way that avoids having undigested food in the stomach during exercise. Take a few minutes to review with your athletes the guidelines for pre-exercise meals and snacks:
ACSM Guidelines
- Eat a meal 3–4 hours before exercise
- Foods should be high in carbohydrates and moderate in protein to boost and sustain fuel stores
- Select easy-to-digest foods that are low in fat and fiber so they don't cause gastrointestinal distress during exercise
- Drink fluids with meals and snacks to promote hydration
- Athletes prone to digestive distress during exercise may do better with a liquid meal or snack before exercise rather than solids
- Experiment with new foods and beverages during practice sessions
Fueling during exercise
According to ACSM, current research supports the benefit of carbs in amounts provided in sports drinks even in endurance events lasting less than 1 hour. Specifically, carbs help to maintain blood glucose levels and improve performance. This is especially the case for athletes who exercise in the morning after an overnight fast when liver glycogen stores are low.
For longer events, consuming 30–60 grams of carbs per hour "has been shown unequivocally to extend endurance performance." Consuming carbs during exercise is especially important in situations where athletes have not eaten a pre-exercise meal or carbohydrate-loaded. Finally, consuming carbs in a single large dose during exercise is not as effective as consuming smaller amounts every 15 minutes or so.
Promoting recovery after exercise
Athletes who have a rest day or two between long and exhausting workouts or competitions can usually recover adequately with normal meals and fluid intake. However, athletes who engage in long, intense daily workouts or morning and afternoon workouts need to maximize recovery between workouts. This requires replenishing carbohydrate fuel stores, repairing and building muscle tissue, and replacing lost fluids and sodium.
ACSM recommends consuming 0.5–0.7 grams carbs per lb (1.0–1.5 grams carbohydrates per kg) body weight within 30 minutes of finishing exercise, and then again at 2–hour intervals for up to 4–6 hours. For a 150-lb (68-kg) athlete, this amounts to 75–105 grams of carbs as soon as possible after exercise, and then repeating this every few hours as needed or consuming high-carb meals. Consuming protein along with carbs after exercise will help to stimulate a fast recovery and provide the amino acids necessary for muscle tissue repair and building. Finally, many athletes will have some degree of net fluid loss after exercise. To replace that fluid loss, gradually drink 16–24 oz (450–675 ml) of fluid for every lb (0.5 kg) body weight lost. The sodium in sweat also needs to be replaced. Consuming sodium-containing rehydration beverages such as sports drinks and recovery drinks, as well as salty foods and snacks will help replace sodium losses, boost fluid intake, and help promote the retention of fluids consumed.
Final words
Your athletes dedicate themselves to hard work in order to perform at their best, whether you're involved with soccer coaching, youth football drills, or any other sporting activity. Help them achieve that goal by ensuring that sound sports nutrition principles are an integral part of their training and competitions.
References:
American Dietetic Association; Dietitians of Canada; American College of Sports Medicine, Rodriguez NR, DiMarco NM, Langley S. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc 2009;41:709–731
Topics:
Pre-Workout, Hydration, Recovery, Energy, Strength training
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