We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Effect of oral androstenedione on serum testosterone and adaptations to resistance training in young men: a randomized controlled trial.
- Authors
King, Douglas S.; Sharp, Rick L.; Vukovich, Matthew D.; Brown, Gregory A.; Reifenrath, Tracy A.; Uhl, Nathaniel L.; Parsons, Kerry A.; King, D S; Sharp, R L; Vukovich, M D; Brown, G A; Reifenrath, T A; Uhl, N L; Parsons, K A
- Abstract
<bold>Context: </bold>Androstenedione, a precursor to testosterone, is marketed to increase blood testosterone concentrations as a natural alternative to anabolic steroid use. However, whether androstenedione actually increases blood testosterone levels or produces anabolic androgenic effects is not known.<bold>Objectives: </bold>To determine if short- and long-term oral androstenedione supplementation in men increases serum testosterone levels and skeletal muscle fiber size and strength and to examine its effect on blood lipids and markers of liver function.<bold>Design and Setting: </bold>Eight-week randomized controlled trial conducted between February and June 1998.<bold>Participants: </bold>Thirty healthy, normotestosterogenic men (aged 19-29 years) not taking any nutritional supplements or androgenic-anabolic steroids or engaged in resistance training.<bold>Interventions: </bold>Twenty subjects performed 8 weeks of whole-body resistance training. During weeks 1, 2, 4, 5, 7, and 8, the men were randomized to either androstenedione, 300 mg/d (n = 10), or placebo (n = 10). The effect of a single 100-mg androstenedione dose on serum testosterone and estrogen concentrations was determined in 10 men.<bold>Main Outcome Measures: </bold>Changes in serum testosterone and estrogen concentrations, muscle strength, muscle fiber cross-sectional area, body composition, blood lipids, and liver transaminase activities based on assessments before and after short- and long-term androstenedione administration.<bold>Results: </bold>Serum free and total testosterone concentrations were not affected by short- or long-term androstenedione administration. Serum estradiol concentration (mean [SEM]) was higher (P<.05) in the androstenedione group after 2 (310 [20] pmol/L), 5 (300 [30] pmol/L), and 8 (280 [20] pmol/L) weeks compared with presupplementation values (220 [20] pmol/L). The serum estrone concentration was significantly higher (P<.05) after 2 (153 [12] pmol/L) and 5 (142 [15] pmol/L) weeks of androstenedione supplementation compared with baseline (106 [11] pmol/L). Knee extension strength increased significantly (P<.05) and similarly in the placebo (770 [55] N vs 1095 [52] N) and androstenedione (717 [46] N vs 1024 [57] N) groups. The increase of the mean cross-sectional area of type 2 muscle fibers was also similar in androstenedione (4703 [471] vs 5307 [604] mm2; P<.05) and placebo (5271 [485] vs 5728 [451] mm2; P<.05) groups. The significant (P<.05) increases in lean body mass and decreases in fat mass were also not different in the androstenedione and placebo groups. In the androstenedione group, the serum high-density lipoprotein cholesterol concentration was reduced after 2 weeks (1.09 [0.08] mmol/L [42 (3) mg/dL] vs 0.96 [0.08] mmol/L [37 (3) mg/dL]; P<.05) and remained low after 5 and 8 weeks of training and supplementation.<bold>Conclusions: </bold>Androstenedione supplementation does not increase serum testosterone concentrations or enhance skeletal muscle adaptations to resistance training in normotestosterogenic young men and may result in adverse health consequences.
- Subjects
ANDROGENS; BLOOD lipids; LIVER; STEROIDS; DRUGS
- Publication
JAMA: Journal of the American Medical Association, 1999, Vol 281, Issue 21, p2020
- ISSN
0098-7484
- Publication type
journal article
- DOI
10.1001/jama.281.21.2020