Effects of anabolic precursors on serum testosterone concentrations and adaptations to resistance training in young men

The effects of androgen precursors, combined with herbal extracts designed to enhance testosterone formation and reduce conversion of androgens to est rogens was studied in young men. Subjects performed 3 days of resistance tr aining per week for 8 weeks. Each day during Weeks 1, 2, 4, 5, 7, and 8, su bjects consumed either placebo (PL; n = 10) or a supplement (ANDRO-6; n = 1 0), which contained daily doses of 300 mg androstenedione, 150 mg DHEA, 750 mg Tribulus terrestris, 625 mg Chrysin, 300 mg Indole-3-carbinol, and 540 mg Saw palmetto. Serum androstenedione concentrations were higher in ANDRO6 after 2, 5, and 8 weeks (p < .05), while serum concentrations of free and total testosterone were unchanged in both groups. Serum estradiol was eleva ted at Weeks 2, 5, and 8 in ANDRO-6 (p < .05), and serum estrone was elevat ed at Weeks 5 and 8 (p < .05). Muscle strength increased (p < .05) similarl y from Weeks 0 to 4, and again from Weeks 4 to 8 in both treatment groups. The acute effect of one third of the daily dose of ANDRO-B and PL was studi ed in 10 men (23 +/- 4 years). Serum androstenedione concentrations were el evated (p < .05) in ANDRO-6 from 150 to 360 min after ingestion, while seru m free or total testosterone concentrations were unchanged. These data prov ide evidence that the addition of these herbal extracts to androstenedione does not result in increased serum testosterone concentrations, reduce the estrogenic effect of androstenedione, and does not augment the adaptations to resistance training.