Intro to Nutrition Unit 9 Review: Sports Nutrition and Physical Performance

Key Nutrients for Athletes

• Carbohydrates provide the primary fuel source for high-intensity exercise and replenish glycogen stores (glucose stored in muscles and liver)
  • Complex carbs (whole grains, legumes) offer sustained energy release
  • Simple carbs (fruits, sports drinks) provide quick energy boosts
• Proteins support muscle growth, repair, and maintenance especially after strength training sessions
  • High-quality protein sources include lean meats, fish, eggs, and dairy
  • Aim for 1.2-2.0 g/kg body weight daily depending on training intensity
• Fats play a role in hormone production, nutrient absorption, and providing energy during low-intensity, long-duration exercise
  • Focus on healthy unsaturated fats (nuts, seeds, avocados, fatty fish)
• Vitamins and minerals support various bodily functions and energy metabolism
  • B-vitamins (thiamin, riboflavin, niacin) help convert food into energy
  • Vitamin D and calcium are crucial for bone health and muscle function
  • Iron is essential for oxygen transport and preventing anemia
• Antioxidants (vitamins C and E) help combat oxidative stress from intense training
• Omega-3 fatty acids (EPA, DHA) reduce inflammation and support heart health

Energy Balance and Body Composition

• Energy balance refers to the relationship between energy intake (calories consumed) and energy expenditure (calories burned)
  • Positive energy balance (consuming more than burning) leads to weight gain
  • Negative energy balance (burning more than consuming) leads to weight loss
• Athletes require sufficient energy intake to fuel training, support recovery, and maintain optimal body composition
• Resting Metabolic Rate (RMR) represents the calories burned at rest for basic bodily functions
  • Factors affecting RMR include age, sex, body size, and muscle mass
• Thermic Effect of Food (TEF) refers to the energy expended during digestion and absorption
• Physical activity level and exercise intensity significantly impact total daily energy expenditure
• Body composition refers to the relative proportions of fat mass and fat-free mass (muscle, bone, organs)
  • Optimal body composition varies by sport and individual goals
  • Excessive body fat can hinder performance, while inadequate body fat may compromise health
• Skinfold measurements, bioelectrical impedance, and DEXA scans assess body composition

Hydration Strategies

• Proper hydration is crucial for athletic performance, thermoregulation, and overall health
  • Dehydration can lead to decreased endurance, strength, and cognitive function
• Fluid needs vary based on individual sweat rates, exercise intensity, duration, and environmental conditions (temperature, humidity)
• Aim to start exercise well-hydrated and replace fluids lost through sweat
  • Pale urine color indicates adequate hydration, while dark urine suggests dehydration
• Drink 16-20 oz of fluid 2-3 hours before exercise to ensure hydration and allow time for excretion
• During exercise, aim to consume 4-8 oz of fluid every 15-20 minutes
  • Sports drinks containing carbohydrates and electrolytes are beneficial for exercise lasting longer than 60 minutes
• Post-exercise, replace fluid losses by drinking 16-24 oz for every pound lost during activity
• Monitoring pre- and post-exercise body weight can help gauge fluid needs
• Sodium and potassium are key electrolytes lost in sweat that need to be replenished
  • Sodium helps retain fluid and stimulates thirst
  • Potassium supports muscle and nerve function

Pre-workout Nutrition

• Pre-workout meals provide energy, prevent hunger, and promote hydration for optimal performance
• Timing and composition of pre-workout meals depend on individual preferences and tolerance
  • Larger meals are best consumed 3-4 hours before exercise
  • Smaller snacks can be eaten 30-60 minutes prior
• Focus on easily digestible carbohydrates to top off glycogen stores and provide quick energy
  • Examples include fruits, whole grain bread, oatmeal, and rice cakes
• Include a moderate amount of lean protein to support muscle function and repair
  • Greek yogurt, eggs, lean meats, or a protein shake are good options
• Limit high-fat and high-fiber foods close to exercise as they may cause gastrointestinal discomfort
• Caffeine (coffee, pre-workout supplements) can enhance alertness and performance
  • Individual tolerance and timing of caffeine intake should be considered
• Experiment with different pre-workout meal options during training to determine what works best

During Exercise Fueling

• Consuming carbohydrates during exercise can delay fatigue and improve performance, especially during prolonged or high-intensity activities
• The body can oxidize 60-90 grams of carbohydrates per hour during exercise
  • Aim for 30-60 grams per hour for exercise lasting 1-2.5 hours
  • For exercise over 2.5 hours, target 60-90 grams per hour
• Simple carbohydrates are preferred as they are quickly absorbed and utilized
  • Sports drinks, gels, chews, and bars are convenient options
  • Whole foods like bananas or honey can also be used
• Combining glucose and fructose sources can increase carbohydrate oxidation rates
• Proper fluid intake is essential to maintain hydration and support nutrient delivery
  • Aim for 4-8 oz of fluid every 15-20 minutes
• For ultra-endurance events, consider adding protein to support muscle repair and reduce muscle breakdown
  • Target 10-15 grams of protein per hour during extended activities
• Practice fueling strategies during training to develop a plan that works for you

Post-workout Recovery

• Post-workout nutrition is crucial for replenishing energy stores, promoting muscle repair and growth, and supporting immune function
• Timing of post-workout meals and snacks is key for optimal recovery
  • Aim to consume within 30-60 minutes after exercise
• Carbohydrates are essential for replenishing depleted glycogen stores
  • Target 1.0-1.5 grams per kg body weight within the first hour post-exercise
  • High glycemic index carbs (white rice, potatoes, bread) are quickly absorbed
• Protein is necessary for muscle repair, growth, and adaptation
  • Consume 20-40 grams of high-quality protein post-workout
  • Whey protein is rapidly absorbed and rich in leucine, which stimulates muscle protein synthesis
• Combining carbohydrates and protein in a 3:1 or 4:1 ratio can optimize recovery
  • Examples include chocolate milk, a turkey sandwich, or a protein shake with fruit
• Rehydration is vital to replace fluids and electrolytes lost through sweat
  • Drink 16-24 oz of fluid for every pound lost during exercise
• Anti-inflammatory foods (cherries, berries, omega-3s) may help reduce muscle soreness and support recovery
• Adequate sleep and rest are also essential components of the recovery process

Supplements and Ergogenic Aids

• Supplements and ergogenic aids are products intended to enhance athletic performance, but they are not a substitute for a well-balanced diet and proper training
• Creatine monohydrate is one of the most well-researched and effective supplements
  • Increases high-intensity exercise capacity and lean body mass
  • Recommended dosage is 3-5 grams per day
• Caffeine is a popular ergogenic aid that can improve alertness, reduce perceived exertion, and enhance endurance performance
  • Effective doses range from 3-6 mg/kg body weight, consumed 30-60 minutes before exercise
• Beta-alanine is an amino acid that can increase muscle carnosine levels, buffering lactic acid and improving high-intensity exercise performance
  • Daily doses of 4-6 grams for at least 2-4 weeks are recommended
• Nitrate-rich foods (beets, leafy greens) or supplements can enhance blood flow and improve endurance performance
  • Consume 6-8 mmol of nitrate, 2-3 hours before exercise
• Protein powders (whey, casein, plant-based) can be convenient sources of protein for meeting increased requirements
• Always prioritize a nutrient-dense diet before considering supplements
• Be cautious of supplements with bold claims or limited research backing their safety and efficacy
• Consult with a sports dietitian or healthcare professional before starting any supplement regimen

Nutrition for Different Sports

• Nutritional needs and strategies vary depending on the specific demands and characteristics of different sports
• Endurance sports (running, cycling, swimming) require a high carbohydrate intake to fuel prolonged aerobic exercise
  • Aim for 6-10 g/kg body weight daily, with a focus on complex carbs
  • During events, target 30-90 grams of carbs per hour, depending on duration
• Strength and power sports (weightlifting, sprinting) rely on anaerobic energy systems and require adequate protein for muscle growth and repair
  • Consume 1.6-2.0 g/kg body weight of protein daily, spread evenly throughout the day
  • Carbohydrate intake should support training demands, with a focus on nutrient-timing around workouts
• Team sports (soccer, basketball, hockey) involve a mix of aerobic and anaerobic demands
  • Carbohydrate needs vary based on training load and playing time, but typically range from 5-7 g/kg body weight daily
  • Protein requirements are similar to strength athletes, at 1.6-2.0 g/kg body weight
• Weight-class sports (wrestling, boxing, martial arts) often involve periods of rapid weight loss followed by recovery
  • Focus on a balanced diet that supports training needs while gradually achieving target weight
  • Avoid severe calorie restriction or dehydration, which can negatively impact performance and health
• Aesthetic sports (gymnastics, figure skating) emphasize leanness and body composition
  • Ensure adequate energy intake to support training and maintain healthy body weight
  • Prioritize nutrient-dense foods and avoid restrictive eating patterns
• Adapt nutrition strategies to individual preferences, cultural background, and sport-specific needs
• Work with a sports dietitian to develop a personalized plan that optimizes performance and health