interesting read If you can muscle through the bad formatting. Sorry it was a PDF and I have no other way to post it.

THE EFFECT OF SHORT-TERM USE OF TESTOSTERONE
ENANTHATE ON MUSCULAR STRENGTH AND POWER IN
HEALTHY YOUNG MEN
SHANE ROGERSON,' ROBERT P. WEATHERBY,' GLEN B. DEAKIN,^ RUDI A. MEIR,'
ROSANNE A. COUTTS,' SHI ZHOU,' AND SONYA M. MARSHALL-
'School of Exercise Science and Sport Management, Southern Cross University, Lismore, New South Wales,
Australia; ^Institute of Sport and Exercise Science, James Cook University, Cairns, Queensland, Australia.
ABSTRACT. Rogerson, S., K.P. Weatherby, G.B. Deakin, R.A.
Meir, R.A. Coutts, S. Zhou, and S.M. Marshall-Gradisnik. The
effect of short-term use of testosterone enanthate on muscular
strength and power in healthy young men. J. Strength Cond.
RcK. 21i2):354-361. 2007.—Use of testosterone enanthate has
been shown to significantly increase strength within 6-12 weeks
of administration (2, 9). however, it is unclear if the ergogenic
benefits are evident in less than 6 weeks. Testosterone enanthate
is classified as a prohibited substance by the World Anti-
Doping Agency (WADA) and its use may be detected by way of
the urinary testosterone/epitestosterone (T/E) ratio (16). The two
objectives of this study were to establish (a) if injection of 3.5
mg kg ' testosterone enanthate once per week could increase
muscular strength and cycle sprint performance in 3-6 weeks;
and (b) if the WADA-imposed urinary T/E ratio of 4:1 could identify
all subjects being administered 3.5 mg-kg ' testosterone
enanthate. Sixteen healthy young men were match-paired and
were assigned randomly 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 ') or saline
injections once weekly for 6 weeks. One repetition maximum
(lRM) strength measures 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 T/E ratio
were measured at the pre (week Q)and post (week 6) time points.
When compared with baseline (pre), lRM 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
enanthate group, but not in the placebo group. Body mass at
week 6 was significantly greater than at baseline in the testosterone
enanthate group (p < 0.01), but not in the placeho group.
Despite the clear ergogenic effects of testosterone enanthate in
as little as 3 weeks, 4 of the 9 subjects in the testosterone enanthate
group (—44%) did not test positive to testosterone under
current WADA urinary T/E ratio criteria.
KEY WORDS, steroid, performance, drug testing, T/E ratio
INTRODUCTION
nabolic androgenic steroids reportedly are
abused by athletes participating in sports that
require muscle strength and power (7, 18).
However, they are classified as prohibited
substances in sport, because their use can offer
an unfair performance advantage and potentially may
be associated with adverse effects on health (17). Welldesigned
placebo-control led studies investigating the ergogenic
effects of testosterone esters have been limited.
Bhasin and coworkers (2) reported that testosterone
enanthate administered at a dosage of 600 mgwk ' was
able to facilitate gains in muscular strength in resistance
training and nonresistance training groups. Giorgi et al.
(9) investigated the effect of testosterone enanthate (approximately
300 mgwk"') combined with resistance
training during a 12-week administration phase. It was
reported that 1 repetition maximum (lRM) bench press
strength increased significantly more in the testosterone
group at weeks 6 and 12, with the majority of the steroidinduced
improvements being made during the initial 6
weeks.
Despite testosterone being shown to have anabolic and
ergogenic effects when taken for a period of 6-12 weeks
(2, 9), there is limited data on whether the effects on
strength and power are evident in less than 6 weeks. Previous
research has found that the greatest gains in
strength were evident in the initial 6 weeks of a 12-week
testosterone administration period, suggesting that the
most rapid gains in strength occur shortly after the commencement
of administration (9). The potential for testosterone
to facilitate improvements in strength and performance
over a short time period could have significant
implications for the timing of drug testing in sport, Testosterone
is classified as a prohibited substance both in
and out of competition by the World Anti-Doping Agency
(WADA) (16). The key measure to detect testosterone
abuse is the urinary testosterone/epitestosterone (T/E) ratio
(16). Weatherby et al. (15) reported that when
strength-trained athletes received testosterone enanthate
for 12 weeks, their performance on a 30-m sprint test was
enhanced. Of potentially greater significance was the
finding that 12 weeks after testosterone administration
was discontinued, the ergogenic effect on sprint performance
was maintained, although the urinary T/E ratio
had returned to baseline (15). Many athletes abusing testosterone
enanthate use long administration phases (12
weeks), which increase the chances of being identified by
a random drug test. If the ergogenic effects of testosterone
enanthate can be achieved using brief administration
phases (3 weeks), athletes may be able to cycle the drug
over a period of weeks instead of months, thereby receiving
the performance-enhancing effects while reducing the
chances of being identified by a random drug test. If this
is true, this represents a threat to sports drug testing and
protocols may need to be modified to increase the chances
of identifying athletes using testosterone esters.
A recent publication highlighted that scientific studies
indicate the usage of anahohc steroids in athletics is no
higher than 6%, whereas anecdotal evidence suggests the
usage is as high as 20-90% (1). One potential explanation
for this is that some drug tests may not be completely
effective, so that some athletes are able to pass a drug
test despite using the drug that the test was designed to
identify. The urinary T/E ratio is the key test to monitor
354
Testing
Training
I nj eel ions
Week 0 1 2 3
*
4
*
6
EFFECT OF TESTOSTERONE ENANTHATE ON STRENGTH AND POWER IN YOUNG MEN 355
TABLE 1. Mean ± SD age, body mass, height, and training
frequency of the suhjects prior to the study [n - 16).
Testosterone Placebo
FIGURE 1. A schematic of the experimental design of the
6-week testosterone study.
exogenous testosterone abuse. Normally, the urinary
T/E ratio is approximately 1:1, and if the ratio exceeds
4:1, the athlete is investigated further to determine if a
doping infraction has occurred (16). However, there is
very little data to indicate what effect the administration
of exogenous testosterone esters such as testosterone
enanthate have on the urinary T/E ratio.
The two objectives of this study were to establish (a)
if a weekly dosage of 3.5 mg-kg"' testosterone enanthate
could increase muscular strength and cycle sprint performance
in 3-6 weeks; and (b) if the WADA-imposed urinary
T/E ratio of 4:1 could identify all subjects being administered
3.5 mg-kg ' testosterone enanthate per week.
METHODS
Experimental Approach to the Problem
The study utilized a double-blind, placebo-controlled 2-
group design. At the beginning of the study, each subject's
height was measured to the nearest 0.5 cm using a wallmounted
stadiometer (Inter 16; Seca, Hamburg, Germany)
and body mass was measured to the nearest 0.1 kg
using an electronic scale (Mettler ID2 Multirange; August
Sauter, Giessen, Germany).
Baseline testing consisted of measuring body mass,
maximal upper and lower body strength, and cycle sprint
performance. Following baseline testing, subjects were
paired based on weight, height, performance measures,
chronological age, training age, nationality, and previous
reported steroid use. Subjects then were assigned randomly
to either a testosterone enanthate or a placebo
group. Both groups of subjects followed the same 6-week
strength and conditioning program. During training, the
testosterone enanthate group received 3.5 mg 'kg ' testosterone
enanthate (Primoteston Depot, Schering AG,
Germany) intramuscularly once per week for 6 weeks
(Figure 11. This dosage of testosterone enanthate exceeds
clinical replacement levels and has heen administered
previously without serious side effects (9). The placebo
group received an equivalent volume of saline solution
(AstraZeneca, New South Wales, Australia). The muscular
strength and power testing was conducted at the pre
(week 0), mid (week 3), and post (week 6) time points.
Strength testing was conducted first, with a 48-hour recovery
period allowed before the cycle sprint test to ensure
that fatigue did not influence the experimental outcomes.
Body mass was measured at the pre (week 0) and
post (week 6) time points only. Urine samples were collected
for determination of the urinary T/E ratio at the
pre (week 0) and post (week 6) time points.
Subjects
Eighteen healthy young men were recruited for this
study. Two subjects did not complete the study, one due
to injury and the other for personal reasons. The characteristics
of the 16 subjects who completed the study are
presented in Table 1. All subjects were fully informed of
the experimental procedures and signed an informed consent
document approved by the Human Research Ethics
Committee of Southern Cross University (ECN-04-99).
Age (y)
Weight (kg)
Height (cm)
Strength training (sessions per
week*)
24
79
181
2
.8 ± 2
.2 ± 6
.2 ± 6
.7 ± 1
.9
.8
.8
.5
25.1
77.6
182,1
2.9
± 4.7
± 5.7
± 7.9
± 0.9
* Training frequency was classified as the mean number of
strength training sessions the subjects performed per week during
the 12 months prior to the study.
Screening and Health Monitoring
Subjects were required to be between 21 and 35 years of
age and to have used no prohibited substances or performance-
enhancing supplements in the previous 6 months.
All subjects reported previous resistance training experience
and, based on self-reported training backgrounds,
were considered moderately to well trained (Table 1). Prior
to inclusion in the study, all subjects underwent a comprehensive
screening process. This included relevant family
medical history, past and present medical condition,
as well as current medication and nutritional supplement
use. A physician performed a physical examination,
which included cardiovascular, respiratory, neural, abdominal,
and musculoskeletal assessment. To identify
any preexisting conditions that may have been exacerbated
by androgen administration, a complete blood
count, lipid profile, liver function test, and resting 12-lead
electrocardiogram was performed. During the study, subjects
were monitored for unusual behavioral or physical
responses; at each weekly dose, a physical check was performed
that included resting hlood pressure and heart
rate, as well as questions on specific known steroid effects.
These tests were performed as a safety and ethical
requirement and the results were not intended to be utilized
as research data.
At the initiation of the study, no subject reported the
use of any nutritional supplements or nonprescription
drugs. As a condition of acceptance into the study, each
potential subject was required to supply a urine sample
that was analyzed for the presence of prohibited substances
according to WADA criteria (16).
Training
The primary objective of the resistance training program
was to increase strength and lean body mass. The resistance
training program scheduled a total of 2-3 resistance
training sessions per week across the 6-week experimental
period. To this end, the resistance training
program prescribed a total of 16 sessions. These sessions
utilized a simple split routine format (Table 2), typically
allowing a minimum 48 hours' recovery before the next
resistance training session utilizing the same body part.
Upper body exercises included bench press, dumbbell
press, shoulder press, lat pull-down, one-arm dumbbell
row, bicep curl, and tricep dip. Lower body exercises included
the squat, leg press, leg extension, leg curl, lunge,
and calf raise.
An RM training range was prescribed for each exercise
within each session of the resistance training routine.
The prescribed repetition ranges (6-12KM per set) utilized
in this study typically are prescribed in programs
designed to increase muscle size and general strength (8).
356 RoGERSON, WEATHERBY, DEAKIN ET AL.
TABLE 2. Individual training session focus across the experimental period.
Week
1
23
4
5
6
Monday
Total body
Lower body
Legs and
shoulders
Legs and
shoulders
Legs and
shoulders
Tuesday
Chest, hack,
and arms
Wednesday
Total body
Chest, hack,
and arms
Test group 1 only
upper hody
Chest, hack.
and arms
Thursday Friday
Total hody
Upper hody
Legs and
shoulders
Legs and
shoulders
Legs and
shoulders
Saturday Sunday
Test group 2 only
upper body
Chest, hack,
and arms
The average prescribed repetition range for each of the
16 resistance training sessions is presented in Figure 2.
A gToup training format was implemented to ensure that
motivation during training remained high. A qualified
strength and conditioning coach closely supervised all 16
training sessions, ensuring that all athletes trained at the
designated intensity.
The resistance training program was periodized and
applied the hasic principles of program design (8). The
average numher of repetitions prescribed per week for the
6-week study is presented in Figure 3. The total numher
of working sets per session ranged from a maximum of
24 to a minimum of 14 (average, 20.5 ± 2.9), and recovery
hetween sets was standardized at 1-2 minutes. The sequence
of exercises in each session was typically from
large muscle mass to small muscle mass. Each suhject
was provided with a training diary in which they were
required to record the actual load (kg) used and the numher
of completed repetitions per set.
1 Repetition Maximum Strength Testing
Lower hody lRM strength was monitored using a 45° leg
press machine (Kolossal, Sydney, Australia). Stoppers
were used to allow the sled to he lowered so that the suhjects'
knee joints reached an angle of 90°. Subjects selfselected
their preferred foot width on the sled, and this
position was marked and recorded for standardization of
future trials. Upper hody lRM strength was monitored
using a modified Smith machine (Plyopower Technology,
Lismore, Australia). Stoppers were used to allow the har
to he lowered to a position 5 cm above each subject's
chest. Subjects selected their preferred grip widths, and
this position was marked and recorded for standardization
of future trials. The bench press and leg press exercises
were selected, because the potential subjects were
familiar with these lifts.
Isotonic lRM testing was conducted according to standardized
procedures published previously (4). Prior to
performing any lifts, a 5-minute standardized general
cardiovascular warm-up was implemented on a cycle ergometer
(Monark 868; Monark-Crescent AB, Varlberg,
Sweden). A specific warm-up then was implemented, consisting
of 8 repetitions at 50% of the estimated lRM, followed
by another set of 3 repetitions at 70% of estimated
lRM. Two minutes separated the 2 warm-up sets. Subsequent
lifts consisted of progressively heavier resistances
until the suhject was unable to successfully complete
a repetition using correct form. A weight midway between
the last successful lift and the failed lift then was attempted
to determine the lRM. Strong verbal encouragement
was provided to all subjects to ensure maximum
efforts (12). A 3-minute recovery period was allowed after
each trial.
10-Second Cycle Sprint Test
Prior to performing the cycle test, a 5-minute standardized
cardiovascular warm-up was implemented on a Monark
868 cycle ergometer (Monark-Crescent). The cycle
sprint testing was conducted on an air-braked front access
cycle ergometer (Exertech Exercise Technology, Sydney,
Australia). The subjects' feet were secured to the
pedals using both toe clips and tape to prevent excess
movement. A 5-second countdown was provided and the
subject was instructed to be cycling at maximum pace on
the count of zero. The test was then initiated and the
subject attempted to maintain maximal power output for
the full 10 seconds. Strong verbal encouragement was
provided to all athletes to ensure maximum effort (12).
Peak power (W) and total work (kJ) were monitored by
way of a photo-optically sensitive diode connected to the
fiywheel, with outputs heing received by an AMLAB data
acquisition and analysis system (AMLAB Technologies,
Lewisbam, Australia). The 10-second cycle test was se-
12 -,
10 -
6 -
4 -
2 -
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Session number
FIGURE 2. The average prescribed repetition range for
of the 16 resistance training sessions.
each
Week
FIGURE 3. The average number of repetitions prescribed per
week across the 6-week study.
EFFECT OF TESTOSTERONE ENANTHATE ON STRENGTH AND POWER IN YOUNG MEN 357
lected because it had been reported previously to be a
highly reliable measure of performance and is less likely
than longer duration tests to be influenced by pacing {19}.
Urinary Testosterone/Epitestosterone Ratio
Collected xirine samples were frozen at —20° C until laboratory
analysis. Analysis of the T/E ratio was performed
in a National Association of Testing Authorities, Australia-
accredited laboratory using gas chromatographymass
spectrometry according to the methods published
previously (5).
Dietary Standardization
To ensure that the dietary intakes were similar, the subjects
were provided all meals for the duration of the
study. Because the research was investigating a drug said
to increase muscle protein synthesis and anabolism, supplementary
protein was allocated to both groups to control
against inadequate protein intakes. The supplementary
protein consisted of Whey Protein Concentrate (Body
Science, Sydney, Australia) administered at a dosage of
60 gd '. The subjects were instructed to consume 30 g in
the morning and 30 g in the evening.
One hour prior to baseline testing, subjects consumed
a standardized meal in the form of a meal-replacement
powder (Mass Monster, Body Science). The meal-replacement
powder was used in an attempt to ensure that the
final meal prior to each testing session was standardized
for its total energy content, as well as its nutrient profile.
This provided greater control over any performance variability
that may have arisen secondary to dietary variations
in the hours prior to each trial.
Standardization of Living Conditions
Accommodations were provided to the subjects for the duration
of the study. Furthermore, because no subjects had
occupational commitments during the 6 weeks of the
study, their living conditions and environmental conditions
were highly standardized. Physical activity outside
of training was limited to light, organized social activities
to minimize any interference with the training program.
Dose-Administration Blinding
Gluteal intramuscular injections were used, which subjects
were unable to view. At the time of injection, subjects
could not distinguish whether a steroid or a placebo
had been injected. All injections were performed by a registered
nurse. At the termination of the study, the 16 subjects
who completed it were provided a questionnaire assessing
how effective the blinding procedures had been.
Four subjects (25%) were unable to determine whether
they had been in the testosterone enanthate or placebo
group. Six subjects (37.51^) were confident that they knew
the group to which they had been assigned; of these 6,
however, 3 had chosen the incorrect group. The remaining
6 suhjects were not confident regarding the group to
which they had been assigned, but they did choose the
correct group (5 placebo, 1 steroid); the majority of them
chose the placebo only because they were of the opinion
that they had not gained sufficient weight to be in a steroid
group. Overall, the blinding procedures appear to
have been successful. It has been concluded that the
study was conducted under strict double blind conditions.
Statistical Analyses
All data were summarized using descriptive statistics
(mean ± SD), and all statistical analysis was performed
• Testosterone
n placebo
Week
FIGURE 4. Body mass for testosterone (n = 9) and placebo (n
= 7) groups before (week 0) and after (week 6) weekly intramuscular
(im) injection of 3.5 mgkg ' testosterone or placebo.
Error bars represent ± SD. * Significantly different from week
0 for testosterone group ip < 0.01).
using SPSS (version 9.0.1; SPSS, Inc., Chicago, IL). Statistical
analysis for strength and cycle performance was
conducted using a 2 X 3 (group [testosterone, placebo]) x
(time Iweek 0, week 3, week 6]) analysis of variance (ANOVA)
with repeated measures. Statistical analysis for
body mass was conducted using a 2 X 2 (group [testosterone,
placebol) x (time Iweek 0, week 6]) ANOVA with
repeated measures. Statistical significance was set at p
< 0.05. When a significant F-ratio was identified, a Fisher's
least significant difference test was used to locate the
pairwise differences between means. Prior to the first
dose, subjects were match-paired and a 1-way ANOVA
was applied to the potential groups to ensure there were
no differences between groups on any variable.
RESULTS
One more subject suffered an injury in the final week and
was unable to complete the IRM leg press component of
the testing, although he had completed all other aspects.
Consequently, statistical analyses on most variables (i.e.,
body mass, bench press, peak power, total work, and the
urinary T/E ratio) were completed on 16 suhjects (testosterone
enanthate, n = 9; placebo, n = 7), whereas tbe
variable leg press was conducted on only 15 subjects (testosterone
enanthate, n ~ 9; placebo, n = 6).
Body Mass
The body mass data are presented in Figure 4. A significant
group X time interaction was identified for body
mass ip < 0.01). Further analysis of this effect indicated
that body mass was higher at week 6 than at week 0 (p
< 0.01) in the testosterone group. No statistically significant
changes in body mass were noted in the placebo
group between weeks 0 and 6. The effect size for body
mass is presented in Table 3.
1 Repetition Maximum Strength
The IRM data for the bench press and leg press exercises
are presented in Figures 5 and 6, respectively. A significant
group X time effect was identified for IRM bench
press strength ip < 0.01). Further analysis of this effect
indicated that IRM bench press strength in the testosterone
group was greater at week 6 than at weeks 3 (p <
0.01) and 0 (p < 0.01). Bench press strength was also
gi'eater at week 3 as compared with week 0 (p < 0.01).
The mean percentage increase in bench press strength
358 RoGERRON, WEATHERBY, DEAKIN ET AL.
TABLE 3. The effect sizes for body mass, 1 repetition mEtximum (IRM) strength measures, and cycle sprint performance.
IRM bench press
Placebo
Testosterone enanthate
IRM leg press
Placebo
Testosterone enanthate
Peak power
Placebo
Testosterone enanthate
Total work
Placebo
Testosterone enanthate
Body mass
Placebo
Testosterone enanthate
Pre-Post effect size
week 0-week 3
0.1
0.4
0.4
0.6
0.1
0.3
0.1
0.6

#

Treatment effect size'''
(T-P)
0.3
0.1
0.2
0.6
#
#
Pre-Post effect size
week 0—week 6
0.1
0.6
0.5
0.7
0.4
0.7
0.3
0.9
0.1
0.8
Treatment effect size*
(T-P)
0.5
0.2
0.3
0.6
0.7
•'• Treatment effect size is calculated by subtracting the Pre-Post effect size for tbe placebo (P) group from the Pre-Post effect size
ofthe Testosterone enanthate (Tj group (13). # = No measure of body mass was taken at the week 3 time point.
140
70
• Testosterone
n placebo
FIGURE 5. One repetition maximum bench press strength for
testosterone (n - 9) and placebo in = 7) groups at weeks 0, 3,
and 6 after weekly intramuscular (im) injection of 3.5 mgkg '
testosterone or placebo. Error bars represent ± SD. * Significantly
different from week 0 for testosterone group (p < 0.01).
"" Significantly different from week 3 for testosterone group (p
< 0,01).
440 -1
410 -
200
• Testosterone
n placebo
FicuRE 6. One repetition maximum leg press strength for
testosterone (n = 9) and placebo (n = 6) groups at weeks 0, 3,
and 6 afler weekly intramuscular (im) injection of 3.5 mg kg '
testosterone or placebo. Error bars represent ± SD. * Significantly
different from week 0, irrespective of group (p < 0,01).
from baseline for the testosterone group was 9% at week
3 and 15% at week 6. Although IRM bench press increased
slightly in the placebo group at both time points,
this did not reach statistical significance. The mean percentage
increase in bench press strength from baseline
for the placebo group was 2% at week 3 and 4% at week
6. The effect sizes for IRM bench press strength are presented
in Table 3.
A significant time effect was identified fbr leg press
strength ip < 0.01). Further analysis of tbis effect indicated
that leg press strength at week 3 was significantly
higher than at week 0 {p < 0.01) and leg press strength
at week 6 was significantly higher than at week 0 (p <
0.01). Leg press strength at week 6 was not significantly
different from week 3. The mean percentage increase in
leg press strength for all subjects from baseline was 13%
at week 3 and 17% at week 6. The effect sizes for IRM
leg press strength are presented in Table 3.
Cycle Sprints
The cycle sprint data are presented in Figures 7 and 8.
A significant time effect was identified for peak power ip
< 0.01). Further analysis of this effect indicated that peak
power at week 6 was significantly higher than at week 0
(p < 0.01) and at week 3 ip < 0.01) irrespective of group.
There was a trend toward peak power being higher at
week 3 compared with week 0, although this failed to
reach statistical significance (p = 0.09). A strong trend
toward a group X time effect was identified, although this
failed to reach statistical significance ip ^ 0.05). The
mean percentage increase in peak power from baseline
for the placebo group was 1% at week 3 and 47c at week
6. The mean percentage increase in peak power from
baseline for the testosterone group was 5% at week 3 and
12% at week 6. The effect sizes for peak power are presented
in Table 3.
A significant group X time interaction was identified
for total work ip < 0.01). Further analysis of this effect
indicated tbat total work was higher in the testosterone
group at week 6 than at weeks 0 and 3 (both, p < 0.01).
Total work was also higher at week 3 as compared with
1800 -,
1600 -
EFFECT OF TESTOSTERONE ENANTHATE ON STRENGTH AND POWER IN YOUNG MEN 359
40-1
36-
30-
• Testosterone
D placebo
S
slU
trca
- 1
25
20
1=;
600
FIGURE 7. Peak power during the 10-second cycle sprint for
testosterone in - 9) and placebo in - 7) groups at weeks 0, 3,
and 6 after weekly intramuscular injection of 3.5 mg-kg ' testosterone
or placebo. Error bars represent ± SD. * Significantly
different from week 0, irrespective of group [p < 0.01). **
Significantly different from week 3, irrespective of group (p <
0.01).
week 0 ip < 0.01). The mean percentage increase in total
work from baseline for the testosterone group was 9% at
week 3 and 14% at week 6. Although total work increased
slightly in the placebo group at week 6, this did not reach
statistical significance. The mean percentage increase in
total work from baseline for the placebo group was 0% at
week 3 and 3% at week 6. The effect sizes for total work
are presented in Table 3.
Urinary Testosterone/Epitestosterone Ratios
At week 0, the T/E ratios for all subjects were within normal
ranges and no urine sample exceeded the 4:1 cutoff
imposed by WADA. At week 6, the urinary T/E ratios of
all subjects in the plaeebo group remained stable and no
subject exceeded the ratio for a positive test according to
WADA criteria (16). At week 6, the urinary T/E ratios in
the testosterone group showed large interindividual variability
(Figure 9). The T/E ratios of 5 of the 9 subjects in
the testosterone group exceeded the WADA cutoff. The
T/E ratios of the remaining 4 subjects in the testosterone
group were below the WADA cutoff, and based on WADA
T/E ratio criteria (16), these subjects would not have tested
positive for testosterone.
• Testosterone
n placebo
FIGURE 8. Total work during the 10-second cycle sprint for
testosterone in = 9) and placebo in = 7) groups at weeks 0, 3,
and 6 after weekly intramuscular injection of 3.5 mg-kg ' testosterone
or placebo. Error bars represent ± SD. * Significantly
different from week 0 for testosterone group (p < 0.01). '-''•
Significantly different from week 3 for testosterone group (p <
0.01).
1 0 •
5 •
Teslostefone Placebo
Group
FIGURE 9. The individual urinary testosterone/epitestosterone
(T/E) ratios for each volunteer in tbe testosterone in = 9) and
placebo (n - 7) groups collected 4 days after the final testosterone
or placebo injection in week 6. Tbe dashed line represents
tbe 4:1 T/E ratio defined by the World Anti-Doping
Agency (WADA) as the upper limit for T/E ratios. * Subjects in
the testosterone group witb T/E ratios below tbe 4:1 cutoff imposed
by WADA, after 6 weeks testosterone use prescribed at
a weekly dose rate of 3.5 mg-kg '.
DISCUSSION
This is the first double-blind, placebo-controlled study to
report a significant increase in strength and athletic performance
after only 3 weeks' use of testosterone enanthate.
Crist, Stackpole, and Peake (6) reported no consistent
effect of testosterone propionate on upper or lower
hody isokinetic strength after 3 weeks. However, the dose
of testosterone used (100 mg-wk ') was low in comparison
with that of the present study. Given that testosterone
administration causes a feedback inhibition of endogenous
luteinizing hormone and testosterone (10), it is unlikely
that the administration protocol used by Crist,
Staekpole, and Peake (6) increased testosterone eoneentrations
outside of normal physiological ranges. In eontrast,
the dosage used in the present study (200-300
mg-wk ') can be considered a supraphysiological dose.
Previous research administering supraphysiological
doses of testosterone also have reported ergogenic effects.
In agreement with this study, Giorgi et al. (9) reported
that testosterone enanthate administered at a dose of approximately
300 mg-wk"' facilitated gains in lRM bench
press after 6 weeks. Likewise, Bhasin and coworkers (2)
reported significant gains in lRM bench press and squat
following the administration of testosterone enanthate at
a dose of 600 mg-wk ' for 10 weeks. More recently, Storer
and eoworkers (14) reported a dose-dependent increase in
maximum voluntary strength in healthy young men. It
was reported that improvements in leg strength and power
were significantly higher in subjects receiving 300 and
600 mg-wk ^ testosterone enanthate compared with those
receiving doses of 25, 50, or 125 mg wk ' (14). The data
from previous studies combined with the findings in this
study suggest that supraphysiological doses of testosterone
are necessary to elicit measurable increases in
strength and power and that the ergogenic benefits are
evident in as little as 3 weeks.
The greater gains in bench press strength, but not leg
press strength, in the testosterone enanthate group likely
360 ROGERSON, WEATHERBY, DEAKIN ET AL.
are attributed to the training background ofthe subjects.
The resistance training backgrounds of the subjects indicated
that most followed programs that favored their
upper bodies. Consequently, the subjects can be considered
more highly trained in the upper body and therefore
less likely to experience rapid gains in upper body
strength. This was evident in the strength gains between
the upper and lower body. After 6 weeks, the mean percentage
strength gains in the bench press exercise were
4 and IS'/r for the placebo and testosterone enanthate
groups, respectively. In contrast, the mean percentage
strength gains in the leg press exercise were 13 and 15%
for the placebo and testosterone enanthate groups, respectively.
The leg press was selected as tbe lower body
IRM testing exercise, because it requires less skill to perform
than a squat does, and therefore reduced the likelihood
of injury during IRM testing. The greater gains in
strength observed in the leg press in comparison to the
bench press may have masked a testosterone effect.
Giorgi et al. (9) reported tbat during 12 weeks of testosterone
enanthate administration, the greatest gains in
bench press strengtb were during tbe first 6 weeks, suggesting
that the body quickly responds to the presence of
testosterone enanthate. As indicated in Figures 5 and 8,
the greatest gains in bench press strength and total work
during the 10-second cycle occurred during the first 3
weeks, whicb would indicate that the actions of testosterone
enanthate occur more quickly than was thought previously.
The effect sizes for IRM bench press and total
work are only slightly larger at week 6 as compared witb
week 3 (Table 3). Consequently, it may be that the initial
weeks of testosterone enanthate administration are the
most beneficial in the context of gains in strength and
athletic performance.
A significant increase in body mass was recorded for
the testosterone enanthate group at week 6, with no significant
increase in the placebo group. Although total energy
intake was not controlled in the present study, all
food was supplied to the subjects. Consequently, both the
steroid and placebo groups had equal access to the same
dietary source. Previous research also has reported significant
gains in body mass after 6 weeks (9) and 10
weeks (2) of testosterone enantbate administration. Consequently,
tbis study provided further support for the
ability of supraphysiological doses of testosterone enanthate
to facilitate gains in body mass, which may be advantageous
to athletes participating in sports in whicb
higb body mass is considered beneficial.
The significant increase in total work in the testosterone
enantbate group and strong trend toward a group x
time effect on peak power in the cycle test is in line with
the findings of Bhasin and coworkers (3), who reported
that leg power increased significantly in men receiving
300 and 600 mg of testosterone enanthate per week, but
not in men receiving 25-, 50-, or 125-mg weekly doses.
Likewise Weatherby et al. (15) reported an ergogenic effect
of testosterone enanthate on 30-m running sprints.
The data from this study, with that of previous work, suggest
that testosterone enanthate can enhance athletic
performance on tests requiring rapid force development
and short maximal efforts.
Detection of exogenous testosterone abuse is monitored
by way of the urinary T/E ratio. Normally tbe urinary
T/E ratio is approximately 1:1, and if the ratio exceeds
4:1, an athlete is investigated further to determine
if a doping infraction has occurred (16). No previous study
investigating the ergogenic effects of testosterone enanthate
has reported urinary T/E ratio data. This study has
raised some serious concerns as to how effective the urinary
T/E ratio is at identifying athletes using moderate
doses of testosterone esters. The dose of testosterone
enanthate used in this study clearly enhanced performance
in as little as 3 weeks, however 4 ofthe 9 subjects
in the testosterone group (44%) would not have tested
positive to testosterone according to tbe latest WADA urinary
T/E ratio criteria (16). The large interindividual variability
in the T/E ratios following testosterone enanthate
administration suggests that some individuals may be
able to use supraphysiological doses of testosterone enantbate
and display only small increases in their urinary
T/E ratios.
The long-term use of anabolic androgenic steroids is
associated with adverse health effects (17). In this study,
the subjects were monitored for side effects ofthe testosterone
enanthate. No changes in blood pressure or beart
rate were detected in subjects in either the steroid or placebo
group. In the placebo group, mild acne occurred in 5
of tbe 7 subjects for periods of 1 to 2 weeks; in the testosterone
enanthate group, however, acne occurred in 6
of the 9 subjects, was more severe, and lasted for more
than 4 weeks after appearing in the first 1 to 2 weeks
after the first dose was administered. Six ofthe 7 placebo
subjects had periods of mild moodiness and irritability; 6
of the testosterone group, however, had more severe
moodiness and irritability over several weeks. Subjects
were asked about their libido during the 6-week study.
Four ofthe placebo group reported small changes, but for
7 of the 9 testosterone subjects, a pattern of decreased
libido in the first week witb an increase in the third and
successive weeks was reported. One reported no change,
and the remaining subject reported a small decrease in
the third week only. One symptom reported by the testosterone
group (5 out of 9) was nipple tenderness from
week 3 until the conclusion of the study. Three subjects
in the testosterone group felt tbat tbeir testicular size had
decreased, whereas one subject reported that he had increased
body hair. Three of the subjects in the testosterone
group reported that the area around the injection site
was sore afber some injections. Overall, the placebo group
did not report side effects of any seriousness; those in the
testosterone group, however, reported adverse effects consistent
with testosterone administration (9) that generally
appeared from weeks 2—3 of the administration period,
Tbe manifestation of these adverse effects appears
to parallel the ergogenic effects produced.
In any study investigating testosterone or other anabolic
androgenic steroid, the possibility of a placebo effect
must be acknowledged. Previous research has reported
that when elite power lifters were given placebo capsules
and were told they were oral anabolic steroids, their
strength levels increased significantly in only 7 days (11).
Testosterone can be associated with side effects such as
acne that may not be seen with a placebo (9). Therefore,
the effectiveness of the blinding procedures needs to be
carefully monitored and reported in researcb investigating
athletic performance or any other variable that may
be influenced by the subjects' expectations. Not all previous
studies have reported the success of their blinding
procedures and consequently, the infiuence of a placebo
effect in these studies cannot be ruled out. In the present
study, the majority of subjects were unable to confidently
determine the group to whicb they had been assigned,
suggesting that this study was conducted under strict
EFFECT OF TESTOSTERONE ENANTHATE ON STRENGTH AND POWER IN YOUNG MEN 361
double-blind conditions and that the results are unlikely
to have been influenced hy expectancy effects.
PRACTICAL APPLICATIONS
This study provides evidence ofthe ability of anaholic androgenic
steroids to enhance muscle strength and power
within weeks of beginning administration. Additionally,
the WADA-imposed urinary T/E ratio of 4:1 did not identify
all athletes who were administered testosterone
enanthate in this study. The findings of this study suggest
that some athletes may be able to use testosterone
enanthate to significantly enhance their performance
without testing positive.
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Acknowledgments
This study was funded by a grant from Mentorn London Television
Corporation. Protein supplements and meal replacement
powders utilized in this study were supplied by Body Science
Australia. Appreciation is expressed to Associate Professor N.
Travis Triplett for her constructive feedback and proofreading
of the manuscript. The results of the present study do not constitute
endorsement of the product by the authors or the National
Strength and Conditioning Association.
Address correspondence to Dr. Shane Rogerson,
[email protected].