Endurance and Ultra-Endurance Athletes

Endurance and Ultra-Endurance Athletes

• Endurance is the ability to repeatedly contract muscles without fatigue. It's measured by the maximum number of repetitions in one minute.
• Cardiovascular endurance is the ability of the heart and blood vessels to deliver oxygen and nutrients to working muscles. It's measured by a maximal treadmill test.
• The primary energy system for endurance exercise is aerobic.
• The anaerobic-aerobic continuum shows the relative use of different energy systems during activities ranging from sprinting (mostly anaerobic) to marathons (mostly aerobic).
• Caloric expenditure for training is high in endurance athletes. Nutritional intake must meet daily energy expenditure.
• Resting energy expenditure (REE) calculations and activity factors aid in determining daily energy needs.
  • Formulas exist for different genders and age groups. Body weight (BW) is a key factor.
• Matching caloric intake with expenditure is challenging in endurance athletes.
• Focus on meeting carbohydrate requirements (30-60 grams/hour) and fluid requirements.
• Sports drinks (6-8% carbohydrate) are suitable.
• A 200- to 300-calorie snack (e.g., half sandwich, milk, or 100% juice) is suggested immediately after exercise.
• A bigger meal should follow within 1 to 2 hours.
• Glycogen depletion (in muscles and liver) can lead to extreme fatigue during endurance exercise.
• Carbohydrate requirements for endurance athletes exercising 1-3 hours daily are 6 to 10 grams per kilogram of body weight.
• For ultra-endurance athletes exercising 4-5 hours or more per day, needs are 8 to 12 grams per kilogram of body weight.
• The carbohydrate intake should account for 50-65% of total daily calories.
• Macronutrient balance should also be maintained.
• Carbohydrate loading is a strategy (gradual increase in carbohydrate intake to 65-70% of total calories) used 6-7 days before an endurance event, using juices, smoothies, etc. This lowers fat and fiber consumption.

Carbohydrate Ingestion - Before/During/After Competition

• Goal prior to competition is to provide the athlete with energy, allowing appropriate time for digestion and absorption before the event.
  • Increased carbohydrate intake prior may allow longer periods between ingestion and the start of competition.
• 1 to 4 grams of carbohydrate per kilogram of body weight during the 1 to 4 hours prior to exercise are generally recommended.
• During competition, the goal is to provide some energy and maintain blood glucose levels.
  • A recommended intake range of 30 to 60 grams of carbohydrates per hour can be easily achieved with sports drinks or gels/bars.
• After competition, the goal is to replenish glycogen stores rapidly, by consuming 1.0 to 1.2 grams of carbohydrate per kg of body weight each hour for 4 hours following exercise. Whole foods, juices, and low-fat dairy products are useful.

Protein Needs in Endurance Athletes

• Protein is not a major energy provider, but its use can increase with high energy expenditures.
• Protein is needed for tissue repair and muscle adaptation.
• 1.2 to 2.0 grams of protein per kilogram of body weight daily is a general recommendation, based on exercise intensity and duration.
• Different protein needs are advised for different activity levels.
  • Athletes with lower training intensity require less protein.
• Protein intake 2-4 hours prior to an event may contribute to benefits like appetite satiation and providing branched-chain amino acids (BCAA).
• Excessive protein intake needs to be avoided.
• Taking protein during competition can help boost BCAA to prevent central fatigue, particularly during ultra-endurance events.
• Protein after competition can be beneficial for promoting recovery with carbohydrate.
  • 15-25 grams of protein (0.25-0.30 grams per kg of body weight) is frequently recommended immediately after endurance exercise.

Fat Needs in Endurance Athletes

• Fats are an energy source, whose use depends on exercise intensity.
• A recommendation of 20-35% of total calories is common.
• High-fat diets or fat-loading strategies are questionable, need further research.
• Potential risks of high-fat diets in this context include slow digestion, gastric upset, and flavor fatigue, and increased cardiovascular disease risk.
• Fat consumption is not recommended immediately before or during exercise due to problematic digestion/absorption and the potential for gastrointestinal upset, despite some research on medium-chain triglycerides (MCT).
• Fat consumption after exercise seems acceptable, as fat stores are unlikely to be depleted, in small amounts, to aid in post-exercise satiety.

Vitamin and Mineral Needs

• Increased energy demands and sweating during endurance exercise mean increased needs for some vitamins and minerals, but avoiding megadosing.
• Key vitamins of concern are B complex, C, and E.
• Key minerals of concern include iron (Fe), calcium (Ca), sodium (Na), and potassium (K).

Fluid Needs

• Fluid loss is a concern in endurance athletes.
• Proper hydration is critical for safety and performance.
• Individual fluid needs should be assessed, possibly by sweat trials and monitoring training-induced weight changes.
• Athletes should use well-established hydration strategies before, during, and after training sessions.

Meal Planning/Event Logistics

• Consider event length, the feasibility of eating, refrigeration/heating requirements, and space for storage and transport.
• Practice the nutrition plan consistently during training.

This quiz explores the essential concepts of endurance and ultra-endurance athletics. Topics include cardiovascular endurance, energy systems involved in endurance exercise, and the importance of nutritional intake to match energy expenditure. Test your knowledge on the physiological aspects that define endurance athletes and their training needs.