Week 1 Carbohydrate and Performance Flashcards
Why is CHO depletion so serious for performance/health?
Because it’s the main source of energy and without carbs the muscle would not be able to receive sufficient fuel.
Why can’t we have an abundance of fat stores, so we can’t the body just “switch” to 100% fat use?
Product of the carbohydrate oxidation, Oxaloacetate combines with Acetyl-CoA to form citrate, which is used in the first step of the Krebs cycle. Carbohydrate produces Pyruvate which is used to create Oxaloacetate, which is used for the krebs cycle and fat oxidation occurs in this cycle.
What are the current guidelines for Carbohydrate intake.
30-75 mins: small amounts or mouth rinse.
1-2 hours: 30g/hour (Intestinal CHO absorption rate may be a limiting factor for exogenous CHO oxidation)
2-3 hours: 60g/hour
>2.5 hours: 90g/hour (Glucose and fructose mix or Maltodextrin and fructose mix)
Is glucose beneficial for performance even by infusion? Why?
No, there are scientific literature saying that infusion does not improve performance, but intaking carbohydrate does. This can suggest that the benefit of carbohydrate is not metabolic in origin.
What are the multiple Transportable Carbohydrates?
What is the mechanism behind this process? How do we maximise benefits?
SLGT1 moves glucose from the intestine to the bloodstream. However, it can only take in a max of 1g of glucose/min, therefore GLUT-5 moves glucose and fructose into the blood stream. To get the benefit of 2 transporters, its important to get SLGT1 saturated (60g/hour)
What are the multiple Transportable Carbohydrates?
What is the mechanism behind this process? How do we maximise benefits?
SLGT1 moves glucose from the intestine to the bloodstream. However, it can only take in a max of 1g of glucose/min, therefore GLUT-5 moves glucose and fructose into the blood stream. To get the benefit of 2 transporters, its important to get SLGT1 saturated (60g/hour)
Does this Carbohydrate guideline apply to everyone?
Guidelines apply to competitive, well-trained athletes
Do Carbohydrates intake lead to better metabolism of the muscle glycogen content?
No It is shown that there is no evidence of sparing of muscle glycogen content
Talk about Hypoglycaemia and carbohydrate ingestion
Research shows that ingestion of Carbs can delay the onset of the central and peripheral consequences of hypoglycaemia.
What perceptions does ingesting carbohydrate from the mouth lead to ?
Perceptions of reward, motivation, pleasure
What does research show about carbohydrate mouth rinse affecting performance?
Placebo group and carbohydrate mouth rinse group showed no difference in the perception of the effort, but Carb mouth rinse allowed athletes to work harder (higher power output) than the placebo group
Before exercise, what contribution does CHO-rich meal have on muscle and liver glycogen concentration (percentage)? When should it be consumed?
3 hours before, and it increases muscle and liver glycogen concentration by 11-15%
Before exercise, what contribution does CHO-rich meal have on muscle and liver glycogen concentration (percentage)?
Explain the Primary stage of carbohydrate ingestion. What occurs in the mouth?
Taste receptors in the tongue detect a sweet stimuli (T1R2, T1R3). The information is sent to the brain. As a result, this the brain activates the feeding circuit and the reward systems giving a sweet appetite.
