Lecture on Carbohydrate Needs Around Physical Activity
Importance of Carbohydrates
- Carbohydrates yield glucose, the body's preferred energy source.
- Adequate carbohydrate intake postpones fatigue and maximizes performance.
Carbohydrate Recommendations
- Based on grams of carb per kilogram of body weight per day.
- Conversion: 1 kg = 2.2 lbs.
Carbohydrate Needs by Activity Level
- Casual exercisers: 3-5g of carb/kg/day.
- Moderate intensity (1 hour/day): 5-7g of carb/kg/day.
- Endurance athletes (1-3 hours/day): 6-10g of carb/kg/day.
- Ultra-endurance athletes (4-5 hours/day): 8-12g of carb/kg/day.
Carbohydrate Loading
- Increases glycogen stores by increasing carb calories in the days/weeks before an event.
- Normally: 55% of calories from carbs; carb loading: 75-80%.
- 1 ounce of glycogen stores 3 ounces of water, leading to weight gain.
Pre-Activity Nutrition
- Carbohydrates are crucial; avoid high fiber, fat, and protein.
- Examples of pre-workout snacks:
- 1 hour before: 30g of carbs, example: apple and peanut butter.
- 2 hours before: Multiply body weight (lbs) by 0.45 for carbs.
- 3 hours before: Multiply body weight (lbs) by 0.9 for carbs.
- More than 3 hours before: Regular mixed meal (carb, fat, protein).
- High carbohydrate meal examples: contains 62-63% calories from carbs.
Nutrition During Physical Activity
- Consume carbs if exercising intensely for more than an hour.
- Options: Banana, salty pretzels, or carb drinks/gels.
- Sports drinks are mostly unnecessary for casual activity.
Post-Activity Recovery Nutrition
- Timing is crucial: eat within 15-30 minutes post-exercise.
- Ideal ratio: 4:1 of carbs to protein for recovery.
- Carbohydrate and protein foods/drinks assist in muscle refueling.
- Examples of recovery snacks:
- Yogurt and fruit, peanut butter and jelly, turkey sandwich, etc.
Energy Bars and Supplements
- Focus on nutrients from whole foods, not bars or supplements.
- Bars may have too much protein/fat, not ideal pre-workout.
Tips for Sports Nutrition
- Do not try untested foods close to performance.
- Small frequent meals with pre/post-workout snacks are ideal.
- Milk is an excellent recovery food (protein, carbs, calcium).
- B vitamins: No extra needed for athletes, sufficient in grains.
Conclusion
- Aim for nutrient intake from foods, not supplements.
These notes summarize the key points on carbohydrate needs surrounding physical activity, focusing on intake before, during, and after exercise, the concept of carbohydrate loading, and practical nutrition advice.