Carbohydrates

Question 1

Carbohydrate oxidation

Answer 1

Body’s improved ability to utilize carbohydrates as a result of exercise. (Enhanced glycogen storage, imrpoved glucose uptake and mitochondrial adaptation).

Question 2

Fat Oxidation

Answer 2

Metabolic process breaking down fatty acids to produce energy. Used at rest and low-moderate intensity exercise

Question 3

Angiogenesis

Answer 3

physiological process where new blood vessels form from pre-existing ones, continuing growth of vasculature by sprouting and splitting.

Question 4

For which types of events are there no performance benefits in training with low glycogen?

Answer 4

Events lasting an hour or more

Question 5

List three drawbacks of training with low glycogen.

Answer 5

1) Compromised immune function

2) Exercise feels harder (less enjoyable)

3) No increased carbohydrate oxidation adaptation

Question 6

State key point of study design of Hansen’s study (2005)

Answer 6

• Participants trained one leg under low carbohydrate availability and the other under high.

Question 7

State training protocol of Hansen’s study (2005)

Answer 7

• ‘Low’ leg was trained twice per day every other day, ensuring 2nd workout began with low muscle glycogen.
• ‘High’ leg was trained once per day every day, always starting with high muscle glycogen.

Question 8

State main findings of Hansen’s study (2005)

Answer 8

Leg that commenced half of training sessions with low muscle glycogen levels had a more pronounced increase in resting glycogen content, higher mitochondria enzyme, and citrate synthase.

(Better endurance adaptations).

Did open up new era of research for exercise physiology.

Question 9

What are two problems of applying Hansen’s study to the real world?

Answer 9

• Subjects were ‘clamped’ at fixed sub-maximal intensity. Con as athletes tend to periodize their training
• Nieman et al found there was a greater risk if upper respiratory tract infections (UTRI’s). with more intense exercise.

Nieman et al also found intense exercise to alter immune cell functions (T- and B- cells).

Question 10

What is the effect of training in depleted and fasted states on fat oxidation

Answer 10

• Increased fat oxidation capacity
• mitochondrial biogenesis and increase mitochondrial density, which is crucial for fat oxidation
• Improved endurance
  Improved metabolic flexibiltiy (switching between different energy sources).

Question 11

What are the risks associated when training with a low carb diet?

Answer 11

• Reduced performance (lower intensity)
• Increased recovery time
• Overreaching
• Immmunodepression

Question 12

What are the main techniques for measuring muscle glycogen content?

Answer 12

• Muscle Biopsy
• MRS
• Ultrasound
• Emerging techniques; Electromagnetic sensors
  Bioimpedance techniques

Question 13

What is the importance of carb intake for optimal oxidation of fatty acids?

Answer 13

• Fasting for 6 hours significantly increases fat oxidation.
• Carbohydrate intake significantly influences fat oxidation during exercise.
  (increased insulin levels, reduce fat oxidation).
• Optimal strategies include; A “crossover” diet approach may be beneficial, where the body is first adapted to a high-fat diet, followed by short-term (36-72h) carbohydrate loading. Maintaining IMTG and glycogen stores.

Question 14

What was found out about fat oxidation in athletes who trained in a fasted and fed state?

Answer 14

They had the same fat oxidation levels.