Applied sport and exercise nutrition Flashcards
What are the main considerations for nutrition requirements?
- Fuel during exercise: carbohydrate/ fat/ protein
- Fluid requirements during/ post-exercise
- Post-exercise recovery: carbohydrate/ protein –> high freq of training, triathlon, multiple training per day = recovery is most important
What are some causes of fatigue during prolonged exercise?
explain some examples:
- substrate depletion
- loss of body fluids
- hyperthermia
Fatigue comes down to factors e.g.: liver glycogen and CHO availability (substrates needed for exercise)
- Also depends on the environment, hyperhydration increases body temperature - increasing water intake. Use of cold foods and drinks to moderate body temperature
- Consuming foods that are more efficient in energy production
What are the CHO intake recommendations for recovery after exercise?
How well do athletes usually meet their energy requirements?
Recovery recommendations can be quite taxing
- Will rapidly reach daily target
around 1-1.2g/kg/hr
As EE goes up, so does EI.
Athletes are able to match this pretty well in a competitive environment
- Large EI can be a burden for athletes to reach
Describe CHO supplementation:
- CHO ingestion before and during exercise has been consistently demonstrated to enhance performance in events lasting >60 minutes
- Strong rational for using CHO intake
What are the
- peripheral
- central
effects of CHO supplementation
- Peripheral Effects:
glycogen sparing - in 2-3hr window is not shown to work for CHO feeding, but does spare liver glycogen
maintenance of blood glucose - no drop in blood glucose, so can supply the muscle and brain maintenance of CHO oxidation - ability to utilize CHO, so more efficient that using e.g.: fat - Central Effects: within brain and its effect from CHO usage
Why is CHO supplementation <60 mins before exercise advised?
High intensity triggers metabolic response for liver to kick out lots of glucose
- Done by a warm up to increase liver glucose output and prevent hyperglycemia
- Consumption 1hr prior to exercise does not influence exercise performance for exercise up to 1hr, over an hour can display performance benefits. Only benefit is psychological
Can you train the gut for CHO supplementation?
yes, CHO given during training to train the gut to absorb more CHO
- High CHO diet cause gut to adapt to use more CHO in the drinks. Gut may be trainable
- Attributed to transporters in the intestine for the gut to take up water
- Glut 4 transporters did not change in response to the guts feeding adaptations
What are some considerations in nutritional requirements?
- Main nutritional considerations:
- Energy balance
- Daily protein intake
- Protein timing around training - intake is most important 1.6 g/kg/day. Distributing protein throughout the day could maximise benefits
What are 2 factors influencing energy requirements?
- Due to greater body mass
- Need for an individual approach
How can injury risk relate to nutritional requirements?
- Injuries cause the need for changing EI as EE is also different. Diet is very important, vit, min, protein are reduced too
- Hydration is very important, fluid intake during exercise can be difficult for the athlete to achieve. Need for an individualised approach, also looking at their electrolyte concentrations.
- Feeding CHO early = better glycogen re synthesis than feeding it later(closer to exercise)
How can you promote recovery with nutrition?
- Promoting recovery is paramount for performance
- Need for a balance between athletes requirements and athletes staying healthy(J-shaped relationship)
Those exercising more are more likely to get ill, could be lack of nutrients or overexercising