Creatine

Question 1

Where is creatine synthesized in the body?

Answer 1

In the liver, pancreas and kidneys

Question 2

What amino acid precursors are creatine made from?

Answer 2

arginine, glycine and methionine

Question 3

What % of creatine is stored in skeletal muscle?

Answer 3

> 95% - approx 50% is obtained from the diet

Question 4

How are intramuscular creatine levels split?

Answer 4

2/3 = PCr
1/3 = free creatine

Question 5

What is the average total creatine pool in muscles?

Answer 5

120 mmol/kg dry muscle mass

upper limit = 160 mmol/kg dry muscle mass

Question 6

What is the average IM creatine stores in vegetarians?

Answer 6

90-110 mmol/kg dm

Question 7

Creatine turnover - how much creatine do we synthesize + excrete per day?

Answer 7

Synthesis ~2g/day
Excrete ~ 2g/day

Question 8

What are the effects of creatine supplementation?

Answer 8

↑ PCr resynthesis = short-term, high-intensity exercise capacity to perform repeated bouts of high-intensity effort

Question 9

What muscle fibres are PCr levels highest in?

Answer 9

Type II fibres

Question 10

How quickly can PCr be depleted?

Answer 10

~10 seconds

Question 11

How long does it take to re-synthesise PCr?

Answer 11

80% re-synthesised in ~4 minutes

Takes much longer for 100%

Question 12

What are best dietary sources of creatine?

Answer 12

Diet (red meat [beef/pork] and some fish [tuna, salmon, cod, herring) → but not enough

Question 13

When is creatine monohydrate better up taken?

Answer 13

Better uptake mixed with a
carbohydrate containing liquid or
food (consume quickly after mixing)

Question 14

Creatine loading protocols - what is the short, high-dose protocol

Answer 14

• 20 g/day (split in 4 doses) for 5
  days
• 0.3 g/kg BM (split in 3-4 doses)
  for 5 days

Question 15

Does creatine have acute effects?

Answer 15

No. Loading protocols are needed

Question 16

Creatine loading protocols - what is the long, low dose protocol?

Answer 16

• 3-5 g/day for 20-30 days

Question 17

What is the maintenance dose for creatine?

Answer 17

• 2-5 g/day

Question 18

How long is a creatine washout period?

Answer 18

4-6 weeks

Question 19

Co-ingestion - why is it advisable to co-ingest creatine with carbs?

Answer 19

Transport and storage of creatine linked with insulin availability.

Also shows to have high whole body creatine retention with high CHO diet + protein-CHO diet.

Question 20

When is creatine best to be used(what types of exercise)?

Answer 20

Single (+1-5%) and repeated bouts (+5-15%) of high intensity exercise.

High-intensity max efforts <150 sec, largest effects on <30 sec tasks.

Question 21

Why would creatine supplementation during endurance exercise be a potential issue?

Answer 21

Causes an increase in body mass

Question 22

Why could creatine have an affect on concussion?

Answer 22

Improvements in cognitive processing in the brain and potentially reduced damage and enhance recovery from mild traumatic brain injury/concussion

Question 23

What individuals have the greatest potential for increases in creatine supplementation?

Answer 23

Individuals that have high muscle creatine levels will experience low creatine uptake from supplements, and vice versa. Therefore, individuals with low muscle creatine levels (e.g., vegetarians) have the greatest potential for increases in response to supplementation.

Question 24

What are the ‘concerns’ about creatine?

Answer 24

• Increase in body mass
• Myths

Question 25

What are potential safety issues of creatine supplementation?

Answer 25

• No evidence of adverse effects
• Mild, temporary gut upset can occur - but can be attenuated with split dose, longer loading protocol and avoidance of high fibre foods with ingestion.
• Contamination: all supplements have a doping risk of some kind. Athletes should only use batch-tested supplements.