Creatine Flashcards
(13 cards)
What are the mechanisms by which Creatine supplementation enhances performance?
- reference
- Increases muscle PCr (especially type II fibres) so maintains ATP turnover, therefore, greater contractile function
- Accelerates recovery of PCr (re-synthesis) post-exercise or between maximal outputs.
- Enhances glycogen storage in muscle
> Jeukendrup & Gleeson, 2010
What are the proposed performance benefits of increased creatine conc in the muscles?
Increased strength and power output in single and repeated attempts.
What are the likely magnitude of benefits of creatine supplementation when used in conjunction with strength training?
- reference
Combination of strength training + creatine supplementation is consistently found to benefit muscle strength, fat free mass and other performance indicators vs training alone.
Vandenberghe (1997) found creatine+lifting = 20-25% greater strength gains over 10 weeks than lifting only in untrained females.
How strong is the evidence into the effect and safety of creatine?
- reference
- Kreider et al (2017)
Over 1000 studies conducted into safety of use.
widely regarded as the most effective nutritional supplement for increasing high-intensity exercise capacity.
Found to be well tolerated and safe for healthy individuals regardless of age or training experience
What is the optimal dosage of creatine for maximal muscle creatine conc in
a) 6 days
b) 30 days
- reference and how much is muscle creatine conc increased by?
a) 20 g /day (4x5 g a day)
b) 3 g /day
both lead to increases of ~20% of total muscle creatine conc.
- Hultman et al (1996)
Does Creatine supplementation lead to most benefit in acute use or chronic use cases and why?
Chronic.
One use won’t lead to supersaturation of muscle creatine stores that result in better performance. Also, weight gain from loading phase just before comp could throw off leverages.
Chronic use will also benefit training performance/volume, leading to greater physical adaptations leading up to comp/performance
How can you increase muscle creatine conc gains during the loading phase?
-reference
Ingest w/ simple CHO which increase muscle creatine uptake via insulin-dependent mechanism.
Green et al (1996) found increased total creatine conc. of 60% after the loading phase when CHO was ingested with creatine as opposed to not.
Outline the potential risks of creatine supplementation
- anecdotal reports of GI and kidney issues, but no conclusive evidence one way or the other.
- stomach cramping if not taken with enough water,
- diarrhea and nausea may occur if too much taken at once, which is why multiple 5 g portions recommended during loading.
- ave weight gain of 1 kg during loading (water weight). Potentially harmful for weight category or endurance athletes.
Where is creatine available from?
Majority of sport nutrition companies, health shops and many online shops.
How well tested is the creatine on the market?
35 tested products on informed sport. Tend to be more expensive than un-tested batches.
Why would non-meat eaters be more in need of creatine supplementation?
Very limited dietary intake of creatine, solely relying on production in the body.
Give evidence to the benefit of creatine supplementation in ATP resynthesis between repeated exercise bouts.
Branch 2003 meta-analysis found sig greater effect of creatine on performance of repeated bouts than single bouts.
How does training status impact effect of creatine supplementation on body comp or performance variables?
b) what are the limitations from the meta-analysis that observed this
- reference
untrained ppts exhibited greater change in performance from baseline, but this could be down to training or learning effect.
b) classification of training status not consistent/reliable across trials.
- Branch (2003)
