Carbohydrate and fat

Question 1

What are 4 functions of carbs?

Answer 1

• Energy (no.1)
• Physical Activity
• Fibre: Health Benefits
• CNS

Question 2

Energy expenditure at rest is provided by what?

Answer 2

Plasma FFA and glucose

Question 3

As exercise intensity increases, what happens to liver glucose output?

Answer 3

Liver glucose output essentially doubles as exercise intensity increases.

Question 4

How does exercise increase carb oxidation?

Answer 4

In an intensity dependent manner. This involves:
- Increase liver glucose output (to = muscle glucose uptake)
- Increased muscle glycogen breakdown

Question 5

At high relative workloads, what is a decisive factors for maximal work time?

Answer 5

Glycogen stores in exercising muscle

Question 6

Why is fatigue strongly correlated with carbohydrate depletion?

Answer 6

• Muscle glycogen depletion
• Hypoglycaemia reflecting liver glycogen depletion

Question 7

What is the evidence that carb feeding can effect fatigue due to carb depletion?

Answer 7

–Carbohydrate loading to increase muscle glycogen
–Carbohydrate during exercise to maintain blood glucose

Question 8

What is the relationship between repeated sprint ability and glycogen % drop?

Answer 8

The greater the glycogen % drop, the greater the drop in repeated sprint ability.

Question 9

What are daily carb recommendations based on?

Answer 9

Body weight (not % energy intake)

Question 10

What are the daily targets (g of carbs) for light energetic demands of training?

Answer 10

Light = 3-5 g/kg/d

Question 11

What are the daily targets (g of carbs) for moderate energetic demands of training?

Answer 11

Moderate = 5-7 g/kg/day

Question 12

What are the daily targets (g of carbs) for high energetic demands of training?

Answer 12

High = 6-10 g/kg/day

Question 13

What are the daily targets (g of carbs) for very high energetic demands of training?

Answer 13

V high = 8-12 g/kg/day

Question 14

When would ‘general fuelling up’ be used?

Answer 14

Prep for events lasting <90 min exercise.

7-12 g/kg/d fuel needs

Question 15

When would ‘carb-loading’ be used?

Answer 15

Prep for event >90 min in sustained, intermittent exercise.

10-12 g/kg/d for 36-48h pre-event

Question 16

What is the main goal on the day of the event?

Answer 16

Ensuring liver glycogen stores are high ready for performance

Question 17

What are carb targets for ‘pre-event fuelling’ (>60 mins)?

Answer 17

1-4 g/kg body mass, consumed 1-4 h before exercise

Question 18

What happens as you get closer to the competition (on day of event)?

Answer 18

Decrease amount of carbs, less fat, less fibre

Question 19

What is main goal after exercise (before next session/comp)?

Answer 19

Replenish muscle glycogen after training/competition.

Question 20

What should daily fat intake be?

Answer 20

20-35% of total energy intake

Question 21

What should proportion of saturdated fat be?

Answer 21

Less than 10% of energy intake.

Question 22

What does fat adaptation, carb restoration study cause?

Answer 22

Fat adaptation:
Increased fat oxidation
Decreased carbohydrate oxidation
Spared muscle glycogen

Question 23

Does fat adaptation, carbohydrate
restoration study cause any effect on a cycle time trial?

Answer 23

No - despite fat adaptations

Question 24

What adaptation does fat adaptation, carbohydrate restoration studies have on high-intensity exercise performance?

Answer 24

Fat adaptation impairs HIIE performance

Question 25

What is a ketogenic diet?

Answer 25

<50g carb/day, fat intake >70-80% energy
~15% or 1.5 g/kg/d protein (not >25%)
- Ensure adequate sodium/potassium

Question 26

How long is a keto diet adaptation?

Answer 26

at least 2-3 weeks
- elevated blood levels of ketones and tissue adaptation to enhance their use as fuel.
- increases use of fat as muscle fuel

Question 27

What does increased rates of fat oxidation result in?

Answer 27

Reduced economy (increased oxygen demand for a given speed).

Question 28

What were the effects of lowcarb/highfat diet compared to high carbs diet?

Answer 28

In contrast to training with diets providing chronic or periodised high carbohydrate availability, adaptation to an LCHF diet impaired performance in elite endurance athletes.