Principles of nutrition Flashcards
Define Nutrition, and Sports & Exercise Nutrition To understand the importance of Energy balance and macronutrient distribution and sports performance To understand the role of CHO and Protein for sports performance To understand the basics concepts of hydration Understand the importance of pre, during & post-exercise nutrition
What is the definition of nutrition?
The provision of nourishment to cells, tissues, organs, systems and the body as a whole
What does nutrition encompass? (2)
- How food influences our body function and health
- Includes dietary guidelines, food composition and roles that various nutrients have in maintain health
What type of curve do you get from nutrient requirements?
Bell curve
What is the definition of sports and exercise nutrition?
The amount, composition and timing of food intake can profoundly affect sports performance
What are the goals of sports nutrition? (8)
Meet the energy and fuel requirements Maintain ideal physique Adaptation/recovery Refuel/hydrate Optimal health and function Reduce risks of sickness and injury Eat for long term health Enjoy food
What are the 3 components of energy distribution?
Carbohydrate
Protein
Fat
What is the composition of the average UK diet compared to healthy?
Protein: 20% | 15%
Carbohydrate: 40% | 60%
Fat: 40% | 25%
What are the daily requirements of carbohydrates?
6-10g/kg/day - to meet energy demands
450g-750g - 75kg athlete
What is the goal of pre-exercise feeding?
Optimize the supply of muscle glycogen and blood glucose late in the exercise bout
What are the recommendations for pre-exercise CHO ingestion? (3)
Eat an easy to digest high CHO meal
3-4 hours before exercise
High glycemic index CHO meals
What are the potential effects of pre-exercise CHO ingestion? (3)
Promote extra muscle glycogen synthesis
Replenish liver glycogen
Increase CHO oxidation during exercise
How much CHO should you take in during exercise and what form should it be?
30-60g/hour
Solid and liquid forms
Why should you take CHO during exercise and not fat or protein?
- Hydration, maintenance of blood glucose, muscle/liver glycogen sparing, prevention of GI distress
- Protein and fat consumed during exercise can delay gastric emptying
What is the best carb combo to enhance performance?
Glucose + fructose
Why is CHO post exercise important?
- Delaying CHO intake following intense exercise may reduce muscle glycogen storage and impair recovery
- First 30mins produces rapid rate of resynthesis
- Replace muscle and liver glycogen
How much CHO should athletes consume after 2hr exercise period?
3g/kg/BW
What happens in glycogen resynthesis after exercise?
- High/moderate glycemic index
- During/immediately post exercise (60min rapid resynth period)
How is glycogen resynthesis increased? (5)
Activation of glycogen synthase induced by: - Glycogen depletion - Muscular contraction - Increased insulin secretion GLUT 4 increases translocation
What are the protein requirements for:
a) healthy adult
b) Endurance trained
c) resistance trained
a) 0.75g/kg/BW
b) 1.2-1.7g/kg/BW
c) 1.4-2.0g/kg/BW
When should you hydrate (and amount) and eat pre-exercise? (3)
- 400-600ml fluid 2 hrs before exercise
- Pre exercise meal 2-4hrs before exercise
- Do not sleep in dehydrated state
How can you have optimal hydration during exercise? (5)
- Limit fluid loss by maintaining fluid levels
- Match intake closely to losses <2% BW
- Maintenance of plasma vol. will maximise endurance
- Minimise gastric distress
- Practise drinking during training
What are the ways to have optimal rehydration after exercise? (5)
- High sodium
- Integrated within the diet (protein/glycogen resynthesis)
- Never only water
- 150% fluid losses
- Caffeine during post exercise has more potent diuretic effect
