title: The effects of polyethylene glycosylated creatine supplementation on anaerobic performance measures and body composition.
abstract: The purpose of this study was to examine the effects of 28 days of polyethylene glycosylated creatine (PEG-creatine) supplementation (1.25 and 2.50 g·d) on anaerobic performance measures (vertical and broad jumps, 40-yard dash, 20-yard shuttle run, and 3-cone drill), upper- and lower-body muscular strength and endurance (bench press and leg extension), and body composition. This study used a randomized, double-blind, placebo-controlled parallel design. Seventy-seven adult men (mean age ± SD, 22.1 ± 2.5 years; body mass, 81.7 ± 10.8 kg) volunteered to participate and were randomly assigned to a placebo (n = 23), 1.25 g·d of PEG-creatine (n = 27), or 2.50 g·d of PEG-creatine (n = 27) group. The subjects performed anaerobic performance measures, muscular strength (one-repetition maximum [1RM]), and endurance (80% 1RM) tests for bench press and leg extension, and underwater weighing for the determination of body composition at day 0 (baseline), day 14, and day 28. The results indicated that there were improvements (p < 0.0167) in vertical jump, 20-yard shuttle run, 3-cone drill, muscular endurance for bench press, and body mass for at least one of the PEG-creatine groups without changes for the placebo group. Thus, the present results demonstrated that PEG-creatine supplementation at 1.25 or 2.50 g·d had an ergogenic effect on lower-body vertical power, agility, change-of-direction ability, upper-body muscular endurance, and body mass.
authors.affiliation: 1Department of Exercise and Sport Science, Human Performance Laboratory, University of Wisconsin-La Crosse, La Crosse, Wisconsin; 2Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska; 3Department of Exercise Science, Creighton University, Omaha, Nebraska; and 4Department of Oral Biology, University of Nebraska Medical Center, Lincoln, Nebraska.
authors.forename: Clayton L
authors.initials: CL
authors.lastname: Camic
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Housh
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Zuniga
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Traylor
authors.forename: Haley C
authors.initials: HC
authors.lastname: Bergstrom
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schmidt
authors.forename: Glen O
authors.initials: GO
authors.lastname: Johnson
authors.forename: Dona J
authors.initials: DJ
authors.lastname: Housh
mesh_terms: D015308:Anaerobic Threshold / Q000187:drug effects*; D054874:Athletic Performance / Q000502:physiology*; D001823:Body Composition / Q000187:drug effects; D003401:Creatine / Q000008:administration & dosage / Q000494:pharmacology*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005080:Exercise Test; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000502:physiology; D010807:Physical Endurance / Q000187:drug effects*; D011092:Polyethylene Glycols; D012420:Running / Q000502:physiology; D014891:Weight Lifting / Q000502:physiology; D055815:Young Adult
chemical_list: D011092:Polyethylene Glycols; D003401:Creatine