9 - Sports nutrition

Question 1

How much ATP can be produced per mol of:
Glycogen (anaerobic glycolysis)
Glycogen (aerobic glycolysis)
Fat (Aerobic beta oxidation)

Answer 1

Glycogen (anaerobic glycolysis) = 3 ATP
Glycogen (aerobic glycolysis) = 39 ATP
Fat (Aerobic beta oxidation) = 129 ATP

Question 2

Which is faster, aerobic or anaerobic glycolysis of glycogen?

Answer 2

Anaerobic but it yields less ATP

Question 3

Muscle fatigue while running a marathon is most likely due to a lack of…?

Answer 3

Muscle glycogen

Question 4

What happens to Pyruvic acid in:

a) Anaerobic glycolysis
b) Aerobic glycolysis

Answer 4

Anaerobic: Pyruvic -> Lactic acid
Aerobic: Pyruvic -> KREBS/ETS cycle

Question 5

What is the harris benedict formula?

Answer 5

Measures your energy needs (BMR + energy expenditure)

Question 6

What are the types of carbohydrates?

Answer 6

Monosaccharides - eg glucose, fructose, galactose
Disaccharides e.g. sucrose, lactose, maltose
Polysaccharides e.g. starch, glycogen, cellulose
Fibre e.g. resistant starches

Question 7

What % energy needs come from carbohydrates?

Answer 7

58%

or 60% at 75% VO2 max

Question 8

How do athletes taper for an event (in terms of carb requirements)

a) 3-4 days prior to event
b) Day before
c) On the day
d) After the event

Answer 8

*3-4 days prior: lower muscle glycogen and train with moderate carbohydrate input
*Day before: Carb load - consume 10g/kg
*On the day: Meal 90 mins to 4hrs before - low in fat and fibre and high in carbs. Moderate in protein.
+ Consume Maltodextrin and glucose every 20 mins
*After: 1.5g per kg carb

Question 9

What are the physiological events in the postprandial period?

a) 0-2 hours
b) 2-4 hours
c) 4-6 hours

Answer 9

a) 0-2 hours: hyperglycaemia, hyperinsulinemia, hypoglucagonemia
b) 2-4 hours: Reactive hypoglycaemia, decreased free fatty acid oxidation, increased appetite
c) 4-6 hours: Counter reg hormone response to euglycaemic and FFA conc

Question 10

Protein / Amino acid:

a) % energy needs =
b) Daily requirement/kg =
c) Endurance athlete req/kg =
d) Resistance athlete req/kg =

Answer 10

a) % energy needs = 2%-15%
b) Daily requirement/kg = 0.8g
c) Endurance athlete req/kg = 1.2-1.4g
d) Resistance athlete req/kg =1.2 - 1.7g

Question 11

What are the energy needs per day for fat?

Answer 11

25-30%

or 66% at 50% VO2 max

Question 12

What are the electrolytes?
Where are they found?
What is their biochemical function?

Answer 12

Sodium and chloride, potassium, phosphorus
Found in water-based body fluid
Na+, K+ extracellular nerve conduction
Cl- and HPO42- intracellular. Maintain osmosis.

Question 13

How much sodium, chloride, potassium and phosphorus do we need per day?

Answer 13

1.5g sodium, 2.3g chloride, 4.7g potassium, 0.7g phosphorus

Question 14

1g salt = __g sodium?

1.g sodium = __g salt?

Answer 14

1g salt = 0.4 g sodium

1.g sodium = 2.5 g salt

Question 15

What are nutraceuticals?

What are Ergogenic acids?

Answer 15

Nutrition or pharmaceuticals that provide benefits
Ergogenics = specific compounds of foods that enhance performance. They affect energy metabolism, the CNS, and muscle mass.

Question 16

Give some ergogenic acids that actually work?

Answer 16

Protein, creatine, sodium bicarbonate, caffeine, beta-alanine, carnosine.

Question 17

What is the role of CP in muscle fatigue?

Answer 17

Increases intramuscular buffering capacity -> delays fall in PH -> delays fatigue

Question 18

What is the step-by-step creation of creatine from Arginine and glycine->muscle fibre

Answer 18

Arginine + Gycine -> Kidney -> Guanidino acetate -> liver -> creatine phosphorylcreatine (in muscle fibre)

Question 19

What is the main role of Creatine?

Where is is synthesized and where is it then found?

Answer 19

Effects energy metabolism and maintains ATP levels
Synthesized in kidney, liver and pancreas
Found in skeletal muscle and excitable tissues

Question 20

What is the recommended dose of creatine for sport performance?

Answer 20

20g per day for 4-5 days (loading)

then 1-2g per day (maintenance)

Question 21

What is the role of Bicarbonate / Citrate in anaerobic processes?

Answer 21

Acts as a buffer for acidosis, lowering PH, inhibiting muscle contraction and fatigue.

Question 22

How does caffeine improve performance? (3)

Answer 22

1) Lowers the perception of effort and fatigue, increases alertness.
2) Stimulates fatty acid mobilization from adipose tissue, increasing supply of fat for muscle, sparing limited glycogen and therefore extending performance time.
3) Affects electrolytes within muscle and promotes cycling of AMP

Question 23

What is the ergogenic caffeine dose?

What is the legal limit?

Answer 23

3-6mg per kg 20-60 mins before exercise
Legal limit is up to 12mg.L urine (500mg in total)
Dependent on individual sensitivity.

Question 24

Caffeine studies show no effect in ____ exercise

but around 20% in _____ exercise

Answer 24

Caffeine studies show no effect in aerobic exercise but around 20% in high intensity exercise

Question 25

Explain how you would carry out a loughborough intermittent shuttle test to find the effect of caffeine vs placebo

Answer 25

Warm up followed by 5 blocks of 15 minutes sprinting, with 3 mins rest between each block. Total exercise time 75 mins total time 90 mins
Then fatigue test

Question 26

Beta alanine:
_____ amino acid.
Binds with _____ to make _____, which prevents __ build up in muscle, delaying fatigue.

Answer 26

Beta alanine:
Essential amino acid.
Binds with L-histidine to make carnosine, which prevents H+ build up in muscle, delaying fatigue.

Question 27

Why not take carnosine instead of beta alanine? (3)

Answer 27

Beta alanine is also a transmitter, acting like caffeine
Limits max carnosine produced - therefore safer
Greater capacity for storage

Question 28

What food is beta alanine found in?
What is the recommended supplementation for athletes?
What intensity is beta alanine most useful for?
What is the side effect?

Answer 28

Food - Beef/pork (vegetarians have low levels)
Supp - 800mg 4-5X daily over 10 weeks
Intensity - high + short, e.g. football, wrestling, boxing
Side effect - paresthesia (pins and needles) above 10mg.kg body weight

Question 29

What are the 3 forms of sports drink?

What do they claim to replace in the body?

Answer 29

Hypotonic, hypertonic, isotonic

replace salt, sugar, electrolytes and fluid

Question 30

What does a good quality sports drink contain, that bad quality does not?

Answer 30

Citric acid, stabilisers, ascorbic acid, vitamins.