Carbohydrate 1

Question 1

How are carbohydrates absorbed ?

Answer 1

Carbohydrate in the lumen, Transferrers through the microvilli into intestinal cells. It’s then absorbed through into the capillaries, then into hepatic portal vein to the liver.

Question 2

Goals or pre-exercise feeding ?

Answer 2

Replenish liver glycogen and encourage some glycogen synthesis

promote extra glycogen synthesis
Increase CHO oxidation during exercise at expense of fat metabolism.

Question 3

Glucose muscle uptake ?

Answer 3

Glucose in blood travels to interstitial space
GLUT4 transferring in myocyte
Transferred into G-6-P by hexokinase
Then into glycolysis or glycogenesis

Question 4

Support for sleep low training?

Answer 4

Increases AMPK and P38 for mitochondrial biogenesis.

Question 5

With fructose derived trioses what are the percentages of what happens to this ?

Answer 5

50% gluconeogenesis to glucose
15-25% gluconeogenesis to glycogen
25% to pyruvate or lactate

Question 6

Some methods to train low ?

Answer 6

Low CHO diet
2x daily training
Long session
Sleep low
No carb recovery
Training after overnight fast.

Question 7

When fructose is transported to the liver what happens when it arrives here ?

Answer 7

Converted to fructose 1-p
then to triose-p

From here it can either be converted to glucose 6-p to be stored or used as energy

Or immediate to pyruvate to aerobically make energy or to lactate.

if lactate can become fatty acids and release triglycerides.

Question 8

Why does exercise increase glucose uptake more than insulin?

Answer 8

Because of the much greater flow of blood allows increased glucose transport to the muscles.

Question 9

Yes vs No considerations for CHO loading.

When to and when not to ?

Answer 9

Should consider.

• High glycogen demand
• Longer than 90 mins continuous
• If diet is low CHO
• No medical reasons not to.

Should not considerer/ non necessary.

• Short / Under 80mins
• Adversely effected by weight gain. 1g glycogen has 3gram water.
• Hi Carb diet already 8-9g/kg/d
• Unstable diabetes

Question 10

Burke’s recommendation for pre exercise meal ?

Answer 10

> 60mins
1.4g/kg
1-4 hours before exercise ?

Question 11

Two pathways of carbohydrate usage ?

Answer 11

Glycolysis

Oxidative Metabolism

Question 12

What are the four sources of carbohydrate and some examples that fit in each ?

Answer 12

Monosaccharides - Single sugar unit
Glucose, fructose, galactose.

Disaccharides - Two sugar units
Sucrose (glucose + fructose) , Maltose (2x glucose), Lactose (Glucose + Galactose)

Oligosaccharide - 8-12 glucose molecules
Maltodextrin

Polysaccharides - Branched long chain glucose molecules.
Amylopectin (starch) , Amylose

Question 13

What is the transport mechanism for glucose to be transported form the intestinal lumen to the blood stream ?

Answer 13

Via Sodium link transporter 1 (SGLT1) into the intestinal cells, Then carried by GLUT2 to the blood stream.

Question 14

What are the General carbohydrate requirements for differing training loads as suggested by Burke et al., 2011?

Answer 14

Light - Low intensity or skill based activity - 3-5g/kg/d

Moderate - 1 hour per day - 5-7g/kg/d

High - endurance program/ 1-3 hours day mod/ high intensity - 7-10g/kg/d

Very High - 4-5 hours mod/high - 10-12g/kg/d

Question 15

Estimated g of carb and calories to this stored in an 80kg man ?

Answer 15

0.52kg

2000kcal

Question 16

What is one benefit of a low CHO diet for endurance adaptation?

Answer 16

Increases AMPK and P38 activation.

This stimulates PCc1a and P53 resulting in mitochondrial biogenisis.