Mechanisms

Question 1

What does Cr supplementation increase?

Answer 1

PCr stores (normally 90-160g).

Question 2

Where is PCr absorbed?

Answer 2

Intestinal mucosa.

Question 3

Describe the reactions involving PCr and ATP.

Answer 3

When muscle use ATP for energy, ATP is broken down into ADP and phosphate.

PCr reacts with ADP to yield more ATP, giving your muscles the energy to be able to contract.

So the more creatine in the body to aid this reaction, the more anaerobic energy the body should have.

Question 4

What else does it increase (REF), but why does Cr still not support aerobic system?

Answer 4

Although Cr increases GLUT4 and glycogen stores (Derave et al., 2003).

After 30 seconds of anaerobic use, ATP production from PCr falls by 80 seconds.

Showing there is no real benefit for Cr ingestion for aerobic performance.

Question 5

What further action does Cr have?

Answer 5

It may facilitate the reuptake of Ca2+ into the sarcoplasmic reticulum, through action of Ca2+ adenosine pump.

Question 6

What about muscle fibres?

Answer 6

Cr found in greater quantities in fast twich fibres compared to slow twitch, with mitochondrial ATP production in FT fibres increasing.

Question 7

3 amino acids required for creatine synthesis?

Answer 7

Glycine, arginine, methionine.

Question 8

What effect to these mechanisms have for performance?

Answer 8

Increased PCr stores promote faster regeneration of ATP between high intensity exercises - allowing athletes to maintain a higher training intensity and improve quality of workouts.

Creatine can also aid in increasing body mass and muscle hypertrophy.

Reuptake of Ca2+ results in increased muscular ability to contract and produce power.

Question 9

Study about increased power and creatine?

Answer 9

Volek et al. (1999):

Observed a significant increase in strength performance after 12 weeks of Cr supplementation alongside heavy resistance exercise.