title: Creatine but not betaine supplementation increases muscle phosphorylcreatine content and strength performance.
abstract: We aimed to investigate the role of betaine supplementation on muscle phosphorylcreatine (PCr) content and strength performance in untrained subjects. Additionally, we compared the ergogenic and physiological responses to betaine versus creatine supplementation. Finally, we also tested the possible additive effects of creatine and betaine supplementation. This was a double-blind, randomized, placebo-controlled study. Subjects were assigned to receive betaine (BET; 2 g/day), creatine (CR; 20 g/day), betaine plus creatine (BET+CR; 2+20 g/day, respectively) or placebo (PL). At baseline and after 10 days of supplementation, we assessed muscle strength and power, muscle PCr content, and body composition. The CR and BET+CR groups presented greater increase in muscle PCr content than PL (p=0.004 and p=0.006, respectively). PCr content was comparable between BET versus PL (p=0.78) and CR versus BET+CR (p=0.99). CR and BET+CR presented greater muscle power output than PL in the squat exercise following supplementation (p=0.003 and p=0.041, respectively). Similarly, bench press average power was significantly greater for the CR-supplemented groups. CR and BET+CR groups also showed significant pre- to post-test increase in 1-RM squat and bench press (CR: p=0.027 and p<0.0001; BET+CR: p=0.03 and p<0.0001 for upper- and lower-body assessments, respectively) No significant differences for 1-RM strength and power were observed between BET versus PL and CR versus BET+CR. Body composition did not differ between the groups. In conclusion, we reported that betaine supplementation does not augment muscle PCr content. Furthermore, we showed that betaine supplementation combined or not with creatine supplementation does not affect strength and power performance in untrained subjects.
authors: School of Physical Education and Sport, University of Sao Paulo, Av Mello de Moraes, 65-Butantã, Sao Paulo, SP, 05508-030, Brazil.
authors: Serena
authors: S
authors: del Favero
authors: Hamilton
authors: H
authors: Roschel
authors: Guilherme
authors: G
authors: Artioli
authors: Carlos
authors: C
authors: Ugrinowitsch
authors: Valmor
authors: V
authors: Tricoli
authors: André
authors: A
authors: Costa
authors: Renato
authors: R
authors: Barroso
authors: Ana Lua
authors: AL
authors: Negrelli
authors: Maria Concepción
authors: MC
authors: Otaduy
authors: Cláudia
authors: C
authors: da Costa Leite
authors: Antonio Herbert
authors: AH
authors: Lancha-Junior
authors: Bruno
authors: B
authors: Gualano
mesh_terms: D000293:Adolescent; D000328:Adult; D001622:Betaine / Q000008:administration & dosage*; D001823:Body Composition / Q000187:drug effects; D003401:Creatine / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D053580:Muscle Strength / Q000187:drug effects* / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D010725:Phosphocreatine / Q000032:analysis; D010919:Placebos
chemical_list: D010919:Placebos; D010725:Phosphocreatine; D001622:Betaine; D003401:Creatine