Performance enhancement and urinary detection after short-term testosterone enanthate use

Document Type

Conference publication

Publication details

Deakin, GB, Rogerson, S, Meir, RA, Coutts, RA, Zhou, S, Marshall-Gradisnik, SM & Weatherby, RP 2006, 'Performance enhancement and urinary detection after short-term testosterone enanthate use', American College of Sport Medicine annual meeting, , Denver, CO, 31 May -3 June, Journal of Medicine and Science in Sports and Exercise, vol. 38, supplement 5, p. S405.


Anabolic Androgenic Steroids (AAS) are prohibited substances in sport due to their ability to improve muscle strength and power. Usually athletes who abuse these substances dose in cycles of up to 8-12 weeks. Whether the effects require this length of time to manifest is unknown. Also unknown is the minimum dose required and whether sports drug testing laboratories are able to detect all cases of AAS use by athletes.

PURPOSE: To determine if the AAS, testosterone enanthate could increase strength and athletic performance in 3-6 weeks and the use the T/E ratio screening measure could detect the use of the steroid over that period.

METHODS: Eighteen healthy young males (25+4.0 yrs) were match-paired and randomly assigned in a double blind manner to either a testosterone enanthate or a placebo group. All subjects performed a structured heavy resistance-training program while receiving either testosterone enanthate (3.5 mg.kg-1) or saline intramuscular injections once weekly for six weeks. 1RM strength measures (bench press and leg press) and 10-second cycle sprint performance were monitored at the pre- (week 0), mid (week 3) and post (week 6) time points. Body mass and the urinary testosterone/epitestosterone (T/E) ratio were measured at the pre (week 0) and post (week 6) time points. Urine samples collected at week 0 were analysed for the presence of WADA prohibited substances. ANOVA with repeated measures was used for statistical analysis.

RESULTS: When compared to baseline (pre), 1RM bench press strength and total work during the cycle sprint increased significantly at week 3 (p <0.01) and week 6 (p <0.01) in the testosterone group but not the placebo group. At week 3, 1RM bench press increased 9% from baseline whilst at week 6 the increase was 15%. No significant differences were found between groups for 1RM leg press or peak power. Body mass at week 6 was significantly greater (7%) than at week 0 in the testosterone group (p <0.01) but not the placebo group. Despite the clear performance enhancing effects of testosterone in as little as three weeks, four of the nine subjects in the testosterone group (44%) had a T/E ratio of < 4. T/E ratios for the testosterone group ranged from 2 to 37. T/E ratios for the placebo group remained unchanged between week 0 and week 6.

CONCLUSIONS: The AAS, testosterone enanthate, enhances 1RM bench press and 10-second cycle sprint performance in 3 weeks in a dose that is used therapeutic ally. Using the T/E ratio of 4:1 (currently used to screen urine samples), not all subjects could be detected who were being administered the steroid and gaining performance enhancement from it.