Ciao Fabio

mi faresti sapere il nome della rivista se la ricordi: l'uni co studio infatti che ricordo sostiene questa cosa è uno studio francese datato.

Cmq vi passo intanto questo:

http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract

Effects of repeated creatine supplementation on muscle, plasma, and urine creatine levels.

Rawson ES, Persky AM, Price TB, Clarkson PM.

Department of Exercise Science, University of Massachusetts, Amherst, Massachusetts 01003.

Rawson, E.S., A.M. Persky, T.B. Price, and P.M. Clarkson. Effects of repeated creatine supplementation on muscle, plasma, and urine creatine levels. J. Strength Cond. Res. 18(1):162-167. 2004.-The purpose of this case study was to examine the effects of repeated creatine administration on muscle phosphocreatine, plasma creatine, and urine creatine. One male subject (age, 32 years; body mass, 78.4 kg; height, 160 cm; resistance training experience, 15 years) ingested creatine (20.(-1) for 5 days) during 2 bouts separated by a 30-day washout period. Muscle phosphocreatine was measured before and after supplementation. On day 1 of supplementation, blood samples were taken immediately before and hourly for 5 hours following ingestion of 5 g of creatine, and a pharmacokinetic analysis of plasma creatine was conducted. Twenty-four-hour urine collections were conducted before and for 5 days during supplementation. Muscle phosphocreatine increased 45% following the first supplementation bout, decreased 22% during the 30-day washout period, and increased 25% following the second bout. There were no meaningful differences in plasma creatine pharmacokinetic parameters between bouts 1 and 2. Total urine creatine losses during supplementation were 63.2 and 63.4 g during bouts 1 and 2, respectively. The major findings were that (a) a 30-day washout period is insufficient time for muscle phosphocreatine to return to baseline following creatine supplementation but is sufficient time for plasma and urine creatine levels to return to presupplementation values; (b) postsupplementation muscle phosphocreatine levels were similar following bouts 1 and 2 despite 23% higher presupplementation muscle phosphocreatine before bout 2; and (c) the increased muscle phosphocreatine that persisted throughout the 30-day washout period corresponded with maintenance of increased body mass (+2.0 kg). Athletes should be aware that the washout period for muscle creatine to return to baseline levels may be longer than 30 days in some individuals, and this may be accompanied by a persistent increase in body mass.


A sostegno dell'efficacia.

Come puoi vedere sono studi indipendenti di università ( so già comunque le critiche che mi faranno...)

Inoltre qui:

http://www.ncbi.nlm.nih.gov/entrez/q...m_uid=14971966

dovreste trovare un lungo elenco di studi sulla creatina.

Quest'altro invece è uno studio dove si indica alla fine come non ci sia particolare degradazione in creatinina e quindi a livello renale non carico particolare o dannoso.

Ovvio tutto ciò vale per chi non ha patologie renali come lo zucchero non va datao ai diabetici per esempio.

So già che avrò critiche ma fa lo stesso.

The effect of 7 days of creatine supplementation on 24-hour urinary creatine excretion.

Burke DG, Smith-Palmer T, Holt LE, Head B, Chilibeck PD.

Department of Human Kinetics, St Francis Xavier University, Antigonish, Nova Scotia, Canada.

Since the discovery that oral ingestion of creatine leads to an increase in intramuscular creatine, its supplementation has become widespread. However, the dosage necessary to maximize retention and create significant increases in intramuscular creatine is poorly understood. In this study, 24-hour urinary creatine and creatinine levels of 20 university men's football players and 20 university men's hockey players involved in a resistance-exercise program and supplementing with creatine were collected and analyzed. In a double-blind, randomized design, 10 football players and 10 hockey players were randomly assigned to either the supplement or placebo group. Subjects provided a 24-hour urine sample twice during the study: once prior to supplementation (baseline) and the second 7 days after daily supplementation and resistance exercise. Creatine dosage was 0.1 g x kg(-1) lean body mass. The quantity of creatine ingested was compared with the amount excreted in the urine of those subjects supplementing with creatine and with placebo. Creatinine levels were compared between the first and second urine collection and between groups. Creatine and creatinine concentrations were determined using high-performance liquid chromatography. In 24-hours, 46% of the ingested creatine was excreted. There was no change in creatine levels for placebo subjects. Creatinine levels remained the same within groups at the first and second collection times (p < 0.05). Our findings indicate that when supplementing with dosages of 0.1 g x kg(-1) lean body mass or between 6 and 8 g at a time, approximately half of the ingested creatine gets excreted. Because there was no change in urinary creatinine, it can be assumed that enhanced degradation of creatine did not occur.


Ciao
A