Endurance and Ultra-Endurance Athletes PDF

Endurance and Ultra-Endurance Athletes Chapter 12  Endurance Muscular Cardiovascular Ability to repeatedly Ability of the heart contract without and blood vessels to fatigue deliver oxygen and Usually measured by...

Endurance and Ultra-Endurance Athletes Chapter 12  Endurance Muscular Cardiovascular Ability to repeatedly Ability of the heart contract without and blood vessels to fatigue deliver oxygen and Usually measured by nutrients to working having an athlete muscles perform a maximal Usually measured by a number of repetitions maximal treadmill test in 1 minute  Which energy systems are utilized during endurance activities? Figure 12.1 The anaerobic–aerobic continuum. The primary energy system relied upon during endurance exercise is the aerobic system.  What are the main nutritional concerns of endurance athletes? Large caloric expenditures required for training Ensuring that caloric intake is sufficient to meet total daily energy expenditure Estimating Total Daily Energy Expenditure  Caloric Intake During Exercise Matching caloric intake with expenditure is difficult and many times not feasible. Focus on meeting carbohydrate (30 to 60 grams/hour) and fluid requirements. Sports drinks (6–8% CHO) are appropriate.  Caloric Intake After Exercise 200- to 300-calorie snack immediately after exercise – 1/2 sandwich – Milk – 100% juice Larger meal within 1 to 2 hours postexercise  Carbohydrates and Endurance Performance Figure 12.2 Glycogen depletion and the sensation of fatigue. If the liver and muscles are depleted of glycogen, the endurance athlete experiences extreme fatigue.  Carbohydrate Requirements 6 to 10 g/kg body weight per day for endurance athletes exercising 1 to 3 hours per day 8 to 12 g/kg body weight per day for ultra- endurance athletes exercising < 4 to 5 hours per day Should amount to 50–65% of total daily calories Macronutrient balance should be maintained  Carbohydrate Loading Taper training 6 to 7 days prior to event. Gradually increase carbohydrate intake to 65–70% of total calories. Juices, smoothies, etc. are excellent sources. As carbohydrate intake increases, total calorie, fiber, and fat consumption should decrease.  Carbohydrate Ingestion Prior to Competition The goal is to provide athlete with energy. Must leave time for digestion and absorption. The larger the carbohydrate intake, the longer time between ingestion and competition. Athletes should experiment with times, amounts of carbohydrates, and food sources. Current recommendation: 1 to 4 g carbohydrates per kilogram body weight in the 1 to 4 hours prior to exercise.  Carbohydrate Ingestion During Competition The goal is to provide athlete with some energy and maintain blood glucose levels. 30 to 60 g carbohydrates per hour is recommended rate of intake (individual tolerance/preference can range from 30 to 90 g per hour). Can be easily supplied by 6–8% carbohydrate sports drink (1 to 2 cups/15 minutes) and/or energy bars, energy gels, and food.  Carbohydrate Ingestion After Competition The goal is to provide for rapid recovery of glycogen stores. Consume 1.0 to 1.2 g carbohydrate per kilogram body weight every hour for 4 hours after exercise. Whole foods, juices, and low-fat dairy products are good options. For other ideas, refer to Table 12.2.  Are protein needs different for endurance athletes? Protein is not a major provider of energy; however, high energy expenditures can increase utilization. May delay fatigue during prolonged exercise. Needed primarily for tissue repair and muscle adaptation. 1.2 to 2.0 g of protein per kilogram body weight per day is current recommendation based on training intensity and duration. Daily Protein Intake Recommendations  Protein Intake Before Competition Research in this area is in its infancy. Protein intake 2 to 4 hours prior may offer benefits. – Appetite satiation – Provision of branched chain amino acids (BCAA) Excessive protein intake should be avoided.  Protein Intake During Competition Research in this area is also in its infancy. May help boost BCAA and prevent central fatigue (especially applicable during ultra- endurance events). May also diminish flavor fatigue. Example food sources: – Meat jerky, trail mix, mixed nuts, peanut butter  Protein Intake After Competition Most important macronutrient is carbohydrate. Combination of carbohydrate with protein may enhance insulin activity, thus accelerating recovery. Recommendation is approximately 15 to 25 grams of protein (0.25 to 0.30 gram per kilogram body weight) immediately following endurance exercise.  Are fat needs different for endurance athletes? Fats serve as a source of energy. Intensity of activity affects utilization. Recommended intake is 20–35% of total calories. High-fat diets or fat-loading effects are questionable; more research is needed. Potential risks of high-fat diets: – Slow digestion/gastric upset – Flavor fatigue – Increased risk for cardiovascular disease  Fat Consumption Immediately Prior to and During Exercise Slow digestion/absorption is an issue. Potential for gastrointestinal upset. Research on medium-chain triglycerides (MCT) has not been convincing. Fat consumption at these times is not recommended.  Fat Consumption After Exercise Main dietary concerns should be on carbohydrate and protein needs of athlete. Fat stores are unlikely to have been depleted. Fats also slow digestion, which can delay delivery of nutrients for recovery. Small amounts of fat can provide flavor and a sense of satiety after exercise.  Vitamin and Mineral Needs of Endurance Athletes Increased energy demands and sweating require increased focus on certain nutrients. Athletes should focus on ensuring adequate intake rather than megadosing with supplements. Vitamins of concern: – B complex, C, and E Minerals of concern: – Fe, Ca, Na, and K  Fluid Needs of Endurance Athletes Fluid loss is a concern in endurance athletes. Maintenance of hydration is critical to safety and performance. Determine individual fluid needs: – Perform sweat trials under different conditions. – Monitor training-induced weight changes. Athletes should practice their hydration strategies before, during, and after training.  Meal Planning/Event Logistics for Endurance Athletes Consider the following factors: – Length of event – Feasibility of eating – Refrigeration/heating – Space for storage and transport of supplies Athlete should practice the nutrition plan in training many times before the day of competition Other considerations?