What athletes eat and drink before and during competition can affect performance. What they eat after competition has a larger effect on recovery. If the time between events is less than 24 hours, recovery nutrition can also influence performance in the next event or game.
This chapter focuses on pre-, during-, and postcompetition nutrition. It also provides guidelines for athletes who want to lose or gain weight. Any discussion of weight is incomplete without addressing disordered eating and eating disorders. Strength and conditioning professionals need to recognize signs and symptoms of eating disorders and take an active role on the treatment team.
Precompetition meals help you:
Glycogen is the main energy source during high-intensity exercise. When glycogen stores become depleted, muscular fatigue increases.
When planning precompetition nutrition, consider timing, meal composition, sport type, and your personal preferences. To reduce the risk of stomach upset, meals closer to the event should be smaller and made up of simpler foods. Precompetition meals and beverages should be familiar, low in fat (to support digestion), and moderate in protein (to promote longer-lasting satiety).
Athletes can choose either high- or low-glycemic carbohydrates before competition because research doesn’t show that one option is consistently better. Although rapidly absorbed carbohydrates (e.g., glucose) can cause a spike and then a drop in blood glucose, levels usually stabilize within 20 minutes, and this drop does not negatively affect performance.
Precompetition meals are especially important for aerobic endurance athletes who perform long-duration activity, particularly in the morning after an overnight fast. When you wake up, blood glucose and liver glycogen stores are low, which reduces carbohydrate availability for exercise. A precompetition meal can help restore glycogen and improve time to exhaustion.
One study examined whether a precompetition carbohydrate meal combined with a carbohydrate-electrolyte sports drink before and during exercise improved aerobic endurance capacity. The results showed that a high-carbohydrate meal before exercise increased endurance running capacity by 9% compared to a placebo drink.
Some endurance athletes who are not chronically adapted to a low-carbohydrate diet may begin exercise with depleted glycogen stores. In that situation, the body may increase muscle protein breakdown to help meet energy needs. Eating a high-carbohydrate diet before exercise can reduce muscle protein breakdown while also providing energy for the immune and nervous systems.
To reduce the likelihood of gastrointestinal discomfort during competition, athletes should:
Carbohydrate loading increases muscle and liver glycogen stores, which can delay fatigue during long-duration aerobic exercise. Several methods exist, but all involve high carbohydrate intake in the days leading up to an event. Studies show carbohydrate loading can increase glycogen stores by up to 20% in men, but it may be less effective in women due to differences in total carbohydrate intake.
Carbohydrate loading is most useful for endurance athletes such as marathon runners, cyclists, and cross-country skiers who are at risk of glycogen depletion. A high-carbohydrate diet for several days before competition, combined with a taper in exercise, can maximize stored glycogen.
Guidelines on carbohydrate intake based on timing before competition:
Athletes should keep a record of food intake and performance responses to fine-tune their precompetition nutrition strategy.
Nutrition during competition is most important for:
Fluids and carbohydrates can directly affect performance. Providing amino acids may help reduce muscle damage.
Hydration during competition helps prevent overheating, dehydration, and heat illness. Athletes should hydrate several hours before exercise so there’s time for fluid absorption and urine output. During exercise, they should drink enough to prevent body weight loss greater than 2%.
The optimal sports drink should contain:
Sports drinks with more than 8% carbohydrate may slow gastric emptying and increase stomach discomfort. Fluid intake guidelines also vary by age and body size:
Aerobic endurance athletes should consume 30-90 g per hour of multiple carbohydrate types (e.g., sucrose, fructose, glucose) during prolonged exercise.
Tennis players and other intermittent-sport athletes should aim for 200-400 ml of fluid per changeover while consuming carbohydrates to support performance.
Consuming carbohydrates during prolonged aerobic endurance exercise can improve performance, reduce immune suppression, and delay fatigue. Sports drinks provide carbohydrates, but during high-intensity exercise they typically can’t match carbohydrate use unless the athlete drinks more fluid than is practical.
Studies suggest that:
Team sports such as soccer, tennis, basketball, and football involve repeated bouts of high-intensity activity. Fatigue in these sports is commonly linked to glycogen depletion and dehydration, so both fluids and carbohydrates are important for maintaining performance.
Studies have shown:
Fructose (found in fruit and many sports drinks) is sometimes linked with stomach upset during exercise. Some athletes experience bloating, gas, or abdominal discomfort because fructose can be absorbed more slowly in the intestine. Combining fructose with glucose or maltodextrin may improve absorption and reduce symptoms.
Athletes should develop individualized hydration strategies based on their training and competition conditions. General guidelines include:
Carbohydrates are an important energy source during resistance training and are especially relevant for strength and power sports. Research shows that weightlifting and strength-based exercise can use substantial amounts of muscle glycogen. Because many studies have measured only a few sets, athletes in strength and power sports - or positions that rely heavily on muscle power (e.g., hammer throwers, offensive linemen in American football) - may experience meaningful glycogen depletion across a full competition or training demand.
If an athlete begins with low carbohydrate stores, muscle glycogen will be depleted further, which can impair performance. Strength and power athletes can help maintain glycogen by consuming carbohydrates before and during competition. Carbohydrate intake after exercise also supports recovery by replenishing muscle glycogen.
Postcompetition meals support three main goals:
Timing matters because postcompetition nutrition helps prepare the body for the next bout of activity. Needs vary by sport, intensity, duration, and individual factors such as body weight and age.
After competition, athletes should:
Many athletes assume carbohydrates must be consumed immediately after exercise. Research suggests immediate intake isn’t always required because glycogen replenishment can continue for up to 24 hours, as long as total carbohydrate intake is sufficient. However, after strenuous endurance events that cause muscle damage (e.g., marathons), glycogen resynthesis may be slower if muscle cells are damaged.
In one study on glycogen resynthesis, athletes consumed high-glycemic meals over a 24-hour period. One group ate carbohydrate-rich meals immediately after exercise, while another group delayed intake for 2 hours. Delaying carbohydrate intake slightly reduced glycogen resynthesis rates but did not completely impair recovery.
Athletes should aim to consume:
Protein after exercise supports muscle repair and adaptation. Research shows that adding protein to carbohydrates post-exercise increases glycogen storage when carbohydrate intake is too low. Protein also stimulates muscle protein synthesis, which is central to recovery and growth.
Key protein recommendations:
Athletes in high-intensity intermittent sports (e.g., basketball, hockey, soccer) may have limited recovery time between games. In tournaments, athletes may play multiple matches in one day, so recovery strategies need to start immediately.
Recovery in high-intensity intermittent sports should focus on:
Strength and power athletes need both carbohydrates and protein after exercise. A single resistance training session can significantly reduce glycogen stores, which can reduce force production and increase muscle weakness.
Recommendations for strength and power recovery:
Concurrent training combines endurance and strength training. Strength training alone typically produces greater strength gains, while concurrent training improves endurance performance but may limit strength development.
Guidelines for concurrent training:
Beyond post-workout nutrition, protein distribution across the day matters. Resistance training increases muscle sensitivity to amino acids for up to 48 hours, so regular protein intake supports ongoing repair.
Daily protein recommendations:
Protein recommendations for various sports:
Aerobic endurance athletes need adequate carbohydrates (8-10 g/kg body weight) and protein (1.0-1.6 g/kg body weight), especially for events lasting 90 minutes or longer.
Key recommendations:
Strength and power athletes may use carbohydrates before and during training to maintain energy and reduce muscle breakdown.
Recommendations:
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