-czy robic przerwe od kreatyny?
-jesli robic to jak dlugo?
Na pierwsze pytanie odpowiedzilismy po czesci tutaj:
na drugie postaram sie opdowiedziec ponizej przedstawiajac kilka badan:
Long-term creatine intake is beneficial to muscle performance during resistance training
Vandenberghe, K., M. Goris, P. Van Hecke, M. Van Leemputte, L. Vangerven, and P. Hespel. Long-term creatine intake is beneficial to muscle performance during resistance training.J. Appl. Physiol. 83(6): 2055-2063, 1997.—The effects of oral creatine supplementation on muscle phosphocreatine (PCr) concentration, muscle strength, and body composition were investigated in young female volunteers (n = 19) during 10 wk of resistance training (3 h/wk). Compared with placebo, 4 days of high-dose creatine intake (20 g/day) increased (P < 0.05) muscle PCr concentration by 6%. Thereafter, this increase was maintained during 10 wk of training associated with low-dose creatine intake (5 g/day). Compared with placebo, maximal strength of the muscle groups trained, maximal intermittent exercise capacity of the arm flexors, and fat-free mass were increased 20-25, 10-25, and 60% more (P < 0.05), respectively, during creatine supplementation. Muscle PCr and strength, intermittent exercise capacity, and fat-free mass subsequently remained at a higher level in the creatine group than in the placebo group during 10 wk of detraining while low-dose creatine was continued. Finally, on cessation of creatine intake, muscle PCr in the creatine group returned to normal within 4 wk. It is concluded that long-term creatine supplementation enhances the progress of muscle strength during resistance training in sedentary females.
poziom kreatyny po dlugotrwalym okresie stosowania (24tygodnie 5g/dzien) wraca do poziomu wejsciowego w ciągu 4 tygodni!
Effect of creatine supplementation on intramuscular TCr, metabolism and performance during intermittent, supramaximal exercise in humans.
This study examined the effect of (a) creatine supplementation on exercise metabolism and performance and (b) changes in intramuscular total creatine stores following a 5 day supplementation period and a 28 day wash-out period. Six men performed four exercise trials, each consisting of four 1 min cycling bouts, punctuated by 1 min of rest followed by a fifth bout to fatigue, all at a workload estimated to require 115 or 125% VO2,max. After three familiarization trials, one trial was conducted following a creatine monohydrate supplementation protocol (CREAT); the other after 28 d without creatine supplementation, in which the last 5 d involved placebo ingestion (CON). Intramuscular TCr was elevated (P < 0.05) in CREAT compared with the final familiarization trial (FAM 3) and CON. Concentrations of this metabolite in these latter trials were not different. In addition, a main effect (P < 0.05) for treatment was observed for PCr when the data from CREAT were compared with CON. In contrast, no differences were observed in the total adenine nucleotide pool (ATP+ADP+AMP), inosine 5'-monophosphate, ammonia, lactate or glycogen when comparing CREAT with CON. Despite the differences in TCr and PCr concentrations when comparing CREAT with other trials, no difference was observed in exercise duration in the fifth work bout. These data demonstrate that creatine supplementation results in an increase in TCr but this has no effect on performance during exercise of this nature, where the creatine kinase system is not the principal energy supplier. In addition 28 d without supplementation is a sufficient time to return intramuscular TCr stores to basal levels.
28dni po skonczonej krotkotrwalej suplemnetacji kreatyna (5dni) poziom kreatyny wraca do normy
Effects of repeated creatine supplementation on muscle, plasma, and urine creatine levels.
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 g.d(-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.
to badanie wyjasnilo dwie sprawy:
-jest pewnien poziom ktorego kreatyna nie przekracza
-potzeeba okolo 30dni+ aby osiagnac normalny poziom kreatyny
w tym wypadku przyjmowana kreatyne w nastepujacy sposob:
5dni x 20g/dzien
5dni x 20g/dzien
po pierwszych 5 dniach poziom fosfokretyny zwiekszyl sie o 45%
w ciagu 30dni spadl o 22%
w ciagu kolejnych 5 dni zwiekszyl sie o 24% (w sumie 45%)
wiec - udowodonione jest po raz kolejny to - ze poziom kreatyny osiaga pewien pulap (maxymalny dla kazdej osoby) - tyle ze u jednej bedzie to trwalo dluzej,u innej osoby krocej
ale jesli sie go osiagnie - bedzie sie utrzymuwal do konca suplementacji dodatkowa kreatyna
tak samo jak okres 'wyplukania' - dla niektorych okres 30dni bedzie okresem za krotkim!!
Creatine supplementation increases muscle total creatine but not maximal intermittent exercise performance
This study investigated creatine supplementation (CrS) effects on muscle total creatine (TCr), creatine phosphate (CrP), and intermittent sprinting performance by using a design incorporating the time course of the initial increase and subsequent washout period of muscle TCr. Two groups of seven volunteers ingested either creatine [Cr; 6 × (5 g Cr-H2O + 5 g dextrose)/day)] or a placebo (6 × 5 g dextrose/day) over 5 days. Five 10-s maximal cycle ergometer sprints with rest intervals of 180, 50, 20, and 20 s and a resting vastus lateralis biopsy were conducted before and 0, 2, and 4 wk after placebo or CrS. Resting muscle TCr, CrP, and Cr were unchanged after the placebo but were increased (P < 0.05) at 0 [by 22.9 ± 4.2, 8.9 ± 1.9, and 14.0 ± 3.3 (SE) mmol/kg dry mass, respectively] and 2 but not 4 wk after CrS. An apparent placebo main effect of increased peak power and cumulative work was found after placebo and CrS, but no treatment (CrS) main effect was found on either variable. Thus, despite the rise and washout of muscle TCr and CrP, maximal intermittent sprinting performance was unchanged by CrS.
badano poziom kreatyny po 5dniach suplementacji dawka 30g
mierzono poziom kreatyny (CR),calkowitej kreatyny(TCR),poziom fosfokreatyny (CRP)
po 14 dniach poziom kreatyny,fosfokreatyny i calkowitej kreatyny - spadaja o ok.50%
dopiero po 28 dniach mozna liczyc na spadek do/lub bliski wartosci poczatkowej!
Zmieniony przez - solaros w dniu 2011-02-22 02:49:46