Urinary creatine and methylamine excretion following 4 x 5 g x day(-1) or 20 x 1 g x day(-1) of creatine monohydrate for 5 days.
In this study, we examined the effect of two creatine monohydrate supplementation regimes on 24-h urinary creatine and methylamine excretion. Nine male participants completed two trials, separated by 6 weeks. Participants ingested 4 x 5 g x day(-1) creatine monohydrate for 5 days in one trial and 20 x 1 g x day(-1) for 5 days in the other. We collected 24-h urine samples on 2 baseline days (days 1-2), during 5 days of supplementation (days 3-7), and for 2 days post-supplementation (days 8-9). Urine was assayed for creatine using high-performance liquid chromatography and methylamine using gas chromatography. Less creatine was excreted following the 20 x 1 g x day(-1) regime (49.25 +/- 10.53 g) than the 4 x 5 g x day(-1) regime (62.32 +/- 9.36 g) (mean +/- s; P < 0.05). Mean total excretion of methylamine (n = 6) over days 3-7 was 8.61 +/- 7.58 mg and 24.81 +/- 25.76 mg on the 20 x 1 g x day(-1) and 4 x 5 g x day(-1) regimes, respectively (P < 0.05). The lower excretion of creatine using 20 x 1 g x day(-1) doses suggests a greater retention in the body and most probably in the muscle. Lower and more frequent doses of creatine monohydrate appear to further attenuate formation of methylamine.
Sale
Craig
C
School of Science and Technology, Nottingham Trent University, Nottingham, UK. craig.sale@ntu.ac.uk
Harris
Roger C
RC
Florance
James
J
Kumps
Alain
A
Sanvura
Robertine
R
Poortmans
Jacques R
JR
D000328:Adult; D015331:Cohort Studies; D003401:Creatine / Q000008:administration & dosage* / Q000652:urine*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D008744:Methylamines / Q000652:urine*; D055815:Young Adult
D008744:Methylamines; C027451:methylamine; D003401:Creatine