supplements

Question 1

what is creatine?

Answer 1

• endogenously synthesised from amino acid precursors arginine, glycine and methionine in liver, pancreas and kidneys
• > 95% skeletal muscle stored
• 50% obtained from diet approx

Question 2

what type of creatine in skeletal muscle takes up 2/3s

Answer 2

• phosphocreatine
• free creatine is the remaining 1/3

Question 3

what is the total creatine pool in muscle averages

Answer 3

• around 120mmol/kg dry muscle mass
• taking supplements can boost creatine storage to 160mmol/kg dry muscle mass

Question 4

how is creatine affected in vegetarians

Answer 4

• lower intramuscular creatine stores (90-110)
• benefit more from supplements

Question 5

what is the bodies creatine turnover?

Answer 5

• produce 2g/day (1g own production and 1g diet)
• excreted 2g/day as creatinine (urine)

Question 6

how do we increase these muscle creatine levels?

Answer 6

• Hultman et al
• 6 day creatine loading increased stores
• supplement only affecting if it reaches target tissue and alters level or concentration of command in target tissue
• stop after 6 days and gradually falls during 4-6 weeks

Question 7

what are the effects of creatine loading?

Answer 7

• can increase their muscle creatine stores
• maximum power and work achieve boosted in creatine supplementation
• storing more = increase in maximal work rate you can perform

Question 8

how does creatine affect hypertrophy?

Answer 8

• increase in upper body and lower body muscles - favours creatine
• supplementation promotes small increase in direct muscles of hypertrophy in upper and lower body

Question 9

what are the effects of increase PCr re synthesis?

Answer 9

• ST , high intensity exercise capacity to perform repeated bouts f high intensity effort
• supplementation increases this rate and princes performance in high intensity exercise
• endurance exercise and brain health

Question 10

explain creatine metabolism and the resynthesis of ATP through PCr

Answer 10

• process of resynthesis ATP through PCr is catalysed by creatine kinase enzyme
• take phosphate from phosphocreatine molecule to combine with ADP resynthesising ATP leaving free creatine
• after high intensity exercise, broken down free creatine with O2 available and work rate reduction you can rebuild molecule

Question 11

are PCr level high in type II or type I fibres

Answer 11

type II - maximal sprint, PCr contribution is initially very high and decreases slowly due to breakdown to sustain ATP production rates

Question 12

how fast can PCr be depleted

Answer 12

• 10 seconds
• longer with creatine supplementation

Question 13

how long to resynthesises 80%

Answer 13

4 minutes
- quicker with creatine supplementation

Question 14

mechanisms of action - supplementation with creatine

Answer 14

• increases Cr stores 30% - increasing PCr resynthesis***
• increases muscle glycogen
• increases growth factor expression
• decreases muscle damage
• training harder and longer = increase in lean mass and strength***

Question 15

how is creatine sourced?

Answer 15

1. diet (tuna, salmon, cod, herring, red meat) - not enough for maximal performance in sport
2. creatine monohydrate (CM) (white powder, absorbed, better uptake mixed with carbs

Question 16

describe the short, high-dose creatine loading protocol

Answer 16

• 20g/day (4 doses) for 5 days
• after 5-6 days boost creatine levels
• maintenance dose of 2g/day keep high as long as you want
• gets creatine levels up quickly

Question 17

describe the long low-dose creatine loading protocol

Answer 17

• 3-5g/day for 20-30 days
• accumulates overtime
• month it it at high level

Question 18

what is a washout period

Answer 18

• reduce creatine levels e.g., weight class sports
• 4-6 weeks

Question 19

what is another way to boost creatine levels

Answer 19

co-ingestion

Question 20

how does co-ingestion work?

Answer 20

• combine creatine with with something inducing insulin response (carbs)
• greater retention of PCr and free creatine
• more effective, gets in muscle quicker than just consuming creatine

Question 21

what is the most effective co-ingestions

Answer 21

• protein and carb
• carb

Question 22

when should you use creatine

Answer 22

• single sprints and repeated bouts of high intensity exercise
• high intensity max efforts less than 150 secs
• intermittent sports
• power and strength based
• interval training

Question 23

individual variability when using creatine

Answer 23

• baseline levels - high muscle creatrine levels will have low creatine uptake from supplements advice versa. low muscle credit elevates greatest potential to increase in response to supplements
• sport type - PCr availability determines performance has effects

Question 24

what are the main concerns

Answer 24

• increase in body mass - water retention. need to consider washout period of 4-6 weeks
• myths - no evidence it causes kidney damage, muscle cramps strains etc.

Question 25

safety issues

Answer 25

• no evidence
• temporary gut upset can occur - happens with lots of dietary supplements
• contamination - doing risk and athletes only use the bath-tested supplements