Bodybuilders' body composition: effect of nandrolone decanoate.
BACKGROUND
The use of androgenic-anabolic steroids (AAS) among bodybuilders to increase muscle mass is widespread. Nandrolone decanoate (ND) is one of the most popular misused AAS, although the effects on body composition are equivocal. Therefore, the purpose of this study was to determine the effect of ND on body composition in male bodybuilders, with special reference to muscle mass alterations.


METHODS
Using a randomized "double-blind" "placebo-controlled" design, 16 experienced male bodybuilders (age: 19-44 yr) either received ND (200 mg.wk(-1), intramuscularly) or placebo for 8 wk. Body composition was assessed using the four-component model, combining results from underwater weighing, dual-energy x-ray absorptiometry (DXA), and deuterium dilution. Total bone mineral content and density were measured using DXA. Water compartments (extracellular water [ECW] and intracellular water [ICW]) were determined using deuterium dilution and bromide dilution.


RESULTS
ND administration resulted in significant increments of body mass (+2.2 kg), fat-free mass (FFM: +2.6 kg), and total body water (+1.4 kg). No significant changes in fat mass, percentage fat, ECW, ICW, ECW/ICW ratio, hydration of the FFM, and on bone mineral measurements were observed.


CONCLUSIONS
The results show that the administration of 200 mg.wk(-1) of ND (intramuscularly) for 8 wk significantly increased body mass and FFM, whereas fat mass, bone mineral content, bone mineral density, and the hydration of the FFM remained unaffected. These data indicate that the changes can be attributed to an increase of muscle mass.
van Marken Lichtenbelt
Wouter D
WD
Department of Human Biology, Maastricht University, The Netherlands. MarkenLichtenbelt@HB.unimaas.nl
Hartgens
Fred
F
Vollaard
Niels B J
NB
Ebbing
Spike
S
Kuipers
Harm
H
D000328:Adult; D045930:Anabolic Agents / Q000494:pharmacology*; D001823:Body Composition / Q000187:drug effects*; D015519:Bone Density / Q000187:drug effects; D001965:Bromides / Q000378:metabolism; D003903:Deuterium / Q000378:metabolism; D004311:Double-Blind Method; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D009277:Nandrolone / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000077603:Nandrolone Decanoate
D045930:Anabolic Agents; D001965:Bromides; D009277:Nandrolone; D003903:Deuterium; D000077603:Nandrolone Decanoate