WK 3 - DIGESTION, NUTRIENTS & DIET PLANNING FOR ATHLETES Flashcards
Energy of each macro?
Carbs: 17kj/g
Protein: 17kj/g
Fat: 37kj/g
Role of Carbs
- Energy source for all tissue.
- ESSENTIAL energy source for brain and red blood cells.
- Preferred fuel source for active muscles.
- Delays fatigue process
- Helps maintain performance for athletes working at high intensity.
play a role in recovery, where it’s important to replace the glycogen being used during activities which are going for >90mins. - Part of Ribose, a structural component of RNA and co-enzyme and Deoxyribose, a structural component of DNA.
- Involved in the immune system and blood clotting.
Types of carbs + their structures
Monosaccharides - Glucose, Fructose aka ‘fruit sugar’, Galactose
Dissaccharides - Lactose aka ‘milk sugar’ (Glucose + Galactose), Sucrose aka ‘table sugar’ (Glucose + Fructose), Maltose (Glucose + Glucose)
- Oligosachharides - Fructans (Fructose chains), Galactans (Galactan chains) found in wheat, rye and legumes
- Polysachharides - Starch (Glucose polymers, such as amylose and amylopectin), Glycogen and cellulouse
Fibre - undigested carbohydrate, usually oligosaccharides, polysaccharides, as well components of plant wall such as lignin
Carb food sources
Grains and cereals, fruit, starchy vegetables & legumes, milk & yogurt, sweets & sugars
Fibre also found in bran, nuts & seeds
What is Glycemic Index (GI)
How quickly carbs are digested and absorbed into the bloodstream to be used as energy.
Low GI?
- Longer to be absorbed & digested
- Avoid consuming later than 3hrs prior to training.
Eg. low GI foods?
Pasta, sweet potato, fruit, dairy, breads, grain.
High GI?
- Easily digested
- Consumed 30 - 60 mins prior to training.
Eg. high GI foods
Ripe banana, lollies, museli, dried fruit, energy bars / gels.
What affects overall glycaemic response
Amount of fat, protein and acid
Amount and types of fibre
Type of starch
Level of processing
Glycemic load?
= more accurate measure
Takes into account the anount of carbs in a serve of food.
Calculating glycemic load
GL = GI / 100 x CHO (g) per serving
Fats
Main energy source for low-intensity activities and endureance events.
- Fat reserves are required for energy storage (in contrast to carbohydrates and proteins, our body has unlimited ability to store fat as adipose tissue)
- Required for nerve transmission
- Fat + cholesterol needed for hormone synthesis (especially testosterone, which can impact the ability to build muscle!)
- Insulation and protection (especially important for athletes who play contact sports)
- Phospholipids are a structural component of cell walls
- Cholesterol is needed to synthesis bile, which is required for digestion
Triglyceride structure
Composed of a glycerol backbone and 3 fatty acids.
Less than 6 carbons = short chain fatty acids
6-12 carbons = medium chain fatty acids
14+carbons = long chain fatty acids
Fat intake recommendation
General population: 20-35% of total energy requirements (less than 10% total energy as saturated fat)
Athletes: 20-35% of total energy requirements (less than 10% total energy as saturated fat). Too low-fat intakes can affect hormones in athletes and should not drop below 20% of total energy.
