The purpose of the present study was to investigate regional changes in body composition
and anthropometric variables induced by nandrolone decanoate in bodybuilders. In a
randomized, double blind, placebo controlled design 16 subjects received weekly intramuscular
injections containing 200 mg nandrolone decanoate (ND) or placebo. Composition of
total body and body parts were assessed using dual energy X-ray absorptiometry (DEXA),
skinfolds and circumferences. Measurements were performed at baseline, after 8 weeks
ND administration period and 6 weeks after drug withdrawal. DEXA revealed that total
body mass (from 76.16 ± 2.70 to 78.73 ± 4.07 kg, p < 0.5) and bone-free lean mass
(from 59.54 ± 2.36 to 63.06 ± 2.99 kg, p < 0.025) increased significantly during ND
administration whereas bone mineral mass remained unchanged. Six weeks after drug
cessation bone-free lean mass was still increased compared to baseline levels. During
ND administration significant increments of bone-free lean mass of the trunk (+ 2.03
kg) and legs (+ 1.08 kg) could be observed. Percentage fat of the legs decreased during
the drug intervention period (- 1.9 %) and remained lowered six weeks after drug withdrawal.
No alteration in any variable of the arms was observed. Skinfolds did not change during
the entire study period in both groups. After 8 weeks ND administration circumference
of the neck was increased (+ 0.9 cm) significantly although all circumferences underwent
non-significant gains. In conclusion, the intramuscular administration of nandrolone
decanoate (200 mg per week) during eight weeks induced an increase of body weight
and bone-free lean body mass in bodybuilders that was mainly situated in the trunk
and legs as determined by DEXA. The changes in the trunk were reflected in the circumferences
but not the alterations in the legs. Skinfolds were not able to detect changes of
fat mass of body parts. DEXA revealed that total fat mass and total percentage fat
remained unaffected by drug administration while percentage fat of the legs decreased
and remained lowered after drug cessation. These data indicate that changes of the
composition of body parts induced by ND are elucidated less accurately by circumferences
or skinfolds rather than by DEXA.
Androgenic-anabolic steroids, lean mass, fat mass, circumferences, skinfolds, DEXA,
doping.
