Week 9 - Creatine

Question 1

What is creatine

Answer 1

Endogenously synthesised from amino acids in the liver, pancreas and kidney (Arginine, glycine & methionine)
>95% is stored in skeletal muscle
Approx 50% obtained from the diet

Question 2

Where is creatine stored

Answer 2

About 2/3 of intramuscular creatine is PCr with remaining being free creatine
Muscle averages 120mmol/kg dry muscle mass
Upper limit at 160mmol/kg dry muscle mass
Vegetarians have reported lower creatine stores (90-110mmol/kg dm)

Question 3

Describe the daily creatine turnover

Answer 3

Synthesis: 2g/day (1g endogenous, 1g exogenous)
Excretion: 2g/day (Creatinine)

Question 4

What are the effects of creatine coming from research

Answer 4

Acute: Increases maximum work and total work done in 30 seconds (isokinetic cycling)
Chronic: Favours upper & lower body muscle hypertrophy
Increased PCr resynthesis

Question 5

Creatine Metabolism during exercise

Answer 5

PCr levels higher in type II fibres than type I fibres
PCr can be depleted in 10s, 80% resynthesised in 4 minutes

Question 6

Benefits of creatine supplementation

Answer 6

Increase Cr stores 30% = Increased PCr resynthesis
Increased muscle glycogen
Increased growth factor expression
Decrease muscle damage
Increase duration and intensity for training, therefore lean mass and strength

Question 7

What are some creatine sources

Answer 7

Diet (red meat, some fish)
Creatine monohydrate (CM)
- White powder, 99% absorbed
- Better uptake with a mixed carbohydrate containing liquid or food
- Synthetic which is suitable for vegetarians and vegans

Question 8

Which diet makes creatine retention most effective

Answer 8

Co-ingestion of Protein-CHO diet or High CHO diet retains creatine most effectively

Question 9

When should creatine be considered to use

Answer 9

Power strength sports
Intermittent sports
Resistance/interval training

• Single (+1-5%) or repeated bouts (+10-15%) of high intensity exercise
• High-intensity exercise (<150s), maximal effects during <30s

Question 10

How to achieve creatine monohydrate loading

Answer 10

Short (20g/day for 5 days)
Long (3-5 d/day for 20-30 days)
Co-ingestion with protein & CHO diets

Question 11

What are some safety and concern issues with creatine supplementation

Answer 11

• Increase in body mass from water retention, may be counteractive in some sports
• Mild, temporary gut upset can occur but can be attenuated with split dose, longer loading protocol and avoidance of high fibre foods
• Contamination, as all supplements have a doping risk
• Currently no evidence suggests long term adverse effects with creatine supplementation when taken appropriately

Question 12

How long is a typically washout period

Answer 12

4-6 weeks

Question 13

Why would vegetarians benefit most from creatine supplementation

Answer 13

Vegetarians have lower muscle creatine levels and have the largest potential increases in response to supplementation

Question 14

What are the typical creatine loading protocols

Answer 14

Short, High dose: 20g/day for 5 days (split in 4 doses)
0.3g/kg/ BM (split in 3-4 doses for 5 days)
Long, low dose: 3-5g/day for 20-30 days
Maintenance dose: 2-5g/day

Question 15

What effects does creatine have on brain health

Answer 15

Anti-inflammatory and anti-oxidant effects

Question 16

Why would some individuals be influenced differently from creatine supplementation

Answer 16

Different individuals have different base levels of creatine

Sports that do not require quick ATP production would not benefit as much (ultra endurance athletes)

Question 17

Other applications of creatine supplementation

Answer 17

• Reduces damage and enhances recovery from mild traumatic brain injury
• Combination of CHO loading and creatine can increase power output of repeated sprints in late stages of prolonged cycling