Creatine supplementation increases muscle total creatine but not maximal intermittent exercise performance

• Published in: Journal of applied physiology (1985) 1999-12, Vol.87 (6), p.2244-2252
• Main Authors: McKenna, Michael J, Morton, Judith, Selig, Steve E, Snow, Rodney J
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Biological and medical sciences; Creatine - metabolism; Creatine - pharmacology; Dietary Supplements; Double-Blind Method; Exercise; Exercise - physiology; Fatigue; Fatigue - etiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Muscle, Skeletal - metabolism; Muscle, Skeletal - physiology; Muscular system; Space life sciences; Striated muscle. Tendons; Vertebrates: osteoarticular system, musculoskeletal system
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1999.87.6.2244

1  Department of Human Movement, Recreation, and Performance, Centre for Rehabilitation, Exercise, and Sports Science, Victoria University of Technology, Melbourne, Victoria 8001; 2  Department of Medicine, Monash Medical School, Alfred Hospital, Prahran, Victoria 3181; and 3  School of Human Movement, Deakin University, Burwood, Victoria 3125, Australia 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-H 2 O + 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