carbohydrate and fat

Question 1

what do carbs do in the body?

Answer 1

• maintain blood glucose concentration - liver regulates this and stores glycogen - bokken up constantly ticking into circulation to maintain concentration - glycogen stores topped up when feeding

Question 2

what is the influence of exercise intensity at rest?

Answer 2

• energy expenditure provides primarily from blood metabolic fuels. serves 60-80% of fuel at rest. blood glucose, tissues oxidise that at rate 40-50% of energy required at rest

Question 3

what is the influence of exercise intensity at low intensity?

Answer 3

• increase in energy expenditure. how much increase depends on how fit individual is. contribution from other fat sources. contribution of muscle glycogen. contribute of fats. 50?50 carb and fat mix

Question 4

what is the influence of exercise intensity at moderate intensity?

Answer 4

• 50/50 fuel ix because o2 available to utilise fat stores

Question 5

what is the influence of exercise intensity at high intensity?

Answer 5

• decline in fats ability to provide ATP and increase in carb requirements - increase of muscle glucose and glycogen - carb stores in danger of being depleted and how can we maintain these

Question 6

how does the liver control glucose?

Answer 6

• exercise increases liver glucose depending on intensity - close matching between muscle glucose uptake and liver glucose output - muscle contracts and extracts glucose from blood providing energy source but danger is blood glucose falling - prevented by physiological response to maintain - liver pumps out more glucose doubling output as exercise gets harder matching output of liver and how much muscle takes up workload - blood glucose stays same as trying to match levels but can drive up slightly

Question 7

exercise increasing carb oxidation dependant on intensity involves what?

Answer 7

1. increase liver glucose output (equal to muscle glucose uptake) 2. increase in muscle glycogen breakdown

Question 8

what diets improve factors?

Answer 8

1. carb loading = food you intake days before are high in carbs 2. food stations in road side in marathons 3. top up as you go

Question 9

why are carbs important during exercise

Answer 9

• cyclists are riding to exhaustion so they need a placebo or carb drink - initial increase of glucose but falling, with placebo they pass out -CHO have slight rise one carb drink is taken

Question 10

fatigue during prolonged strenuous exercise

Answer 10

• fatigue correlated with carb depletion - muscle glycogen depletion - hypoglycaemia reflecting liver glycogen depletion - diet can affect this - carb loading increases muscle glycogen - carbs during exercise to maintain glucose

Question 11

what is the carb recommendation for light exercise?

Answer 11

3-5g/kg/d as demands not as high due to low energy

Question 12

what is the carb recommendation for moderate exercise?

Answer 12

5-7g/kg/d

Question 13

what is the carb recommendation for high exercise?

Answer 13

6-10g/kg/d

Question 14

what is the carb recommendation for very high exercise?

Answer 14

8-12g/kg/d

Question 15

what happens what insufficient carb intake?

Answer 15

• high carb diet and glycogen stores fall = recover well so start in similar situation at beginning - keep ups quality of trying for longer - low carb diet = not a lot of recovery after exercise and keeps depleting and feel fatigued before starting exercise. this could cause overtraining

Question 16

how do you fuel leading up to competition lasting <90 mins?

Answer 16

• 7-12 g/kg/d. carb loading: 10-12g/kg/d for 36-48 h pre-event

Question 17

how to fuel day of event lasting >60 mins

Answer 17

1-4g/kg body mass consumed 1-4 hours before exercise

Question 18

how do you intake after exercise

Answer 18

• replenish muscle glycogen - 4 hr window post is best to maximise glycogen intake - co-ingestion with protein = insulin spike - rat of synthesis boost with protein and carb intake

Question 19

recommended fat intake

Answer 19

• 2-35% energy intake - saturated 10%

Question 20

functions of fat diet

Answer 20

• fuel, protection, cell membrane constituents, precursors of bile, hormones and steroids, palatability

Question 21

how do you adapt to consuming fat

Answer 21

• train hard when consuming and rest when having high carbs to restore glycogen

Question 22

what is ketosis

Answer 22

• lowering CHO intake and increasing fat intake induces ketosis for several weeks - ensures stable fuel source for exercise muscle when low CHO available - shift to ketones and fats - benefit endurance performance