Advances in Physical Education
2011. Vol.1, No.1, 1-5
Copyright © 2011 SciRes. DOI:10.4236/ape.2011.11001
The Effects of Pre-exercise High Energy Drink on Exercise
Performance in Physically Active Men and Women
Marko D. Stojanovic, Mirjana V. Stojanovic, Kristina Kanostrevac,
Dragoljub Veljovic, Bojan Medjedovic, Sergej M. Ostojic
Faculty of Sport Sciences and Tourism, Metropolitan University, Serbia
Received August 1st, 2011; revised August 14th, 2011; accepted August 17th, 2011.
The effect of a pre-exercise energy sport drink on the exercise performance was examined in twenty re-
creationally active subjects. A randomized, double-blind, placebo-controlled research study design was con-
ducted. Subjects underwent two testing session separated by 7 days, consisted of handgrip strength test, coun-
rmovement (CMJ) and vertical jump (VJ) as well as incremental test to exhaustion on motorized treadmill.
Before the second trial, they were randomly provided either a placebo (PLA;maltodextrin) or the supplement
(NP; commercially marketed as Ultimate Nox PumpTM,). Analysis of variance revealed no differences between
supplement and placebo g r o u p in strength, CMJ, VJ and maximal oxygen uptake (VO2max) (p > 0.05). Significant
difference between groups over time was observed in maximal heart rate, heart rate recovery and time to
exhaustion (p < 0.05). The present study indicate that a high energy drink consumed 40 minutes before exercise
can enhance exercise performance by increasing the total time to fatigue during incremental testing.
Keywords: Caffeine, Endurance, Heart Rate, Ergogenic Aid
Several physiological and pharmacological agents have been
used by both athletes and recreationally active population to
enhance exercise performance. In addition, there is a growing
number of sports supplements commercially promoted as effec-
tive nutritional ergogenic aids nowadays, with annual sale ex-
pected to surpass 9 bilion dollars by the year 2011 in US alone
(Report Buyer, 2007). However, there is often a lack of objec-
tive evidence to support those claims (Juhn, 2003). During the
past decade, the high-energy drinks have been introduced by
sport supplement industry. The main ingredients of such bev-
erages are caffeine, creatine, carbohydrates, B vitamins and
amino acids, with most of them proved to have ergogenic effect
(Graham, 2001; Bemben & Lamonte, 2005; Jeukendrup et al.,
1999). High-energy drinks also contain taurin and glucuro-
nolactone, ingredients that have been found to elevate mood,
alertness, and concentration (Mandel et al., 1985; Alford, 2001)
and therefore might also contribute to enhanced performance.
Although the ergogenic potential of these ingredients has been
established, effects of their combination on exercise perform-
ance have not been extensively examined. A recent study has
suggested that when stimulants or energy compounds are pro-
vided in more complex combination (e.g. high energy drinks),
the ergogenic effect may be enhanced (Hoffman, 2007). Anec-
dotally, it appears that recreational population uses high energy
drinks for both endurance and power/strength performance en-
hancement. They believe that using high energy supplements
will result in increased overall performance. Unfortunately,
most information available is based upon empirical evidence.
There has been little research to examine the ergogenic effects
of such drinks, particularly when administered pre-exercise.
While it has been presented that upper body strength training
volume significantly increased in 15 healthy young adults
(Forbes et al., 2007), no differences in bench press and leg
press 1-repetition maximum, total weight lifted and anaerobic
power were also reported (Astorino et al., 2007; Hoffman et al.,
2009). Furthermore, though high energy drink have been found
to augment endurance performance and aerobic power in rec-
reationally active subjects (Walsh et al., 2010; Byars et al.,
2010), no differences in run time-to-exhaustion, perceived exer-
tion or maximal blood lactate concentration were observed in
17 physically active university students (Candow et al., 2009).
As previous studies are equivocal, additional research appears
warranted. Moreover, none of the above mentioned studies
controlled the subject’s nutrition during the study and espe-
cially 48 h preceding testing, which could bias the obtained
results. Therefore, the purpose of the present study is to exam-
ine the effects of pre-exercise high energy drink on wide range
of exercise performance indices in recreational athletes con-
ducting study with controlled pre-exercise diet regimens. We
hypothesized that single dose of pre-exercise high energy drink
will increase handgrip strength, anaerobic power, aerobic power
and time to exhaustion in physically active young men and
Twenty healthy, recreationally active subjects (M=10; F=10)
were recruited to participate in this study. The physical
characteristics of the subjects are presented in Table 1.
Following an explanation of all procedures, risks, and benefits,
each subject gave his informed consent before participation in
this study. Subjects were advised to refrain from physical
Table 1.
Selected physical characteristics of the subjects.
Variables Nox-pump (n = 10) Placebo (n = 10)
Age 20.40 ± 4.56 22.60 ± 4.55
Height (cm) 172.71 ± 9.75 174.51 ± 7.65
Weight (kg) 67.47 ± 14.23 70.03 ± 3.87
Note: Values are mean ± SD. No significant differences were found between
groups at p < 0.05
activity for 24 hours, food and drink for 2 hours before exercise
testing, and instructed not to engage in additional physical
activity during the study. All research procedures were approved
by the institutional review board.
Experimental Procedures
The study was conducted using a randomized, double-blind,
placebo-controlled research design. Three days prior to the
baseline testing subjects met a nutritionist who instructed them
how to maintain normal dietary pattern during the study. Each
participant was given a balanced general isoenergetic dietary
plan (roughly based on estimated basal metabolic rate and phy-
sical activity) for the 48h period before each testing. Com-
pliance was monitored by analysing 3-d food records with av-
erag e daily energy intake, macronutrient content, and B complex
vitamins intake calculated (Nutribaze, Phoenix, AR, USA).
Subjects were strongly instructed not to use any performance-
enhancing nutritional supplementation between trials. Each
subject reported to the laboratory for 2 identical experimental
testing sessions at the same time of day (Winget et al.,1985)
and the same day of the week, one week apart. Total par-
ticipation time for each testing session was approximately 1
hour. During the first visit to laboratory, weight and height
were measured for each subject. Body mass was measured
using BC-554 body composition monitor (Tanita Corp., Tokyo,
Japan) to the nearest 100 g, and height was determined with
portable stadiometer (SECA, Hamburg, Germany) to the
nearest millimeter, with barefoot subjects wearing underwear
only. All anthropometric measures were carried out by the same
investigator. Subjects underwent a battery of tests consisted of
hand grip test, countermovement (CMJ) and vertical jump (VJ)
test as well as an incremental test to exhaustion on a motorized
treadmill. Handgrip strength (kg) was measured with a Jamar
hydraulic hand dynamometer (J. A. Preston Corporation,
Clifton, NJ, USA). After the individual size adjustment, the
subject maximally squeezed the grip twice with every hand,
while being in the upright stance and dynamometer holding
close to body (arms fully extended). The higher value was
included in further analysis.CMJ and VJ were estimated using a
contact mat (Jump Mat, Axon, USA). Before testing, the sub-
jects were allowed to warm up on their own (e.g., jogging,
calisthenics) but were requested not to engage in static
stretching. During a warm-up period, several familiarization
jumps were conducted. CMJ requires the individual to begin in
an upright posture with their feet shoulder width apart and with
hands on the hips. After a brief downward phase (semi squat
position) subjects jump straight up in the air with an all-out
effort, maintaining hands on the hips to prevent arms from
contributing to the jump and landing with extended legs on
both feet at the same time. VJ has basically the same kinematical
pattern, with arms allowed to swing thus contributing to jump
height as only difference. Three attempts for each jump type
were allowed with the highest value included in further analysis.
Jump height was calculated from the time the subject was off
the mat by the computer which was connected to the platform.
Incremental pseudo-ramp test protocol was conducted on a
computer-driven motorized treadmill (13620 treadmill, Va-
cumed, California, USA) with heart rate monitored continuously
throughout the test session with a Polar S-810 (Polar ElectroOY,
Finland). Expired air was collected and analyzed through a
2-way valve using VistaVo2Lab automated gas analysis system
(VacuMed, California, USA). The gas analyzer and volume
transducer were calibrated according to manufacturer’s
specification. Following warm-up (3 min of running at 3.8
mph), incremental protocol was applied until volitional fatigue.
The highest heart rate (HR) at the end of the test was recorded
as HRmax, while decrease of HR in the first minute after the test
was recorded as heart rate recovery (HRR) index (Shetler et al.
2001). In addition, time to exhaustion (END) and maximal
oxygen uptake (VO2max) were obtained. VO2max was defined as
the average of the two highest single consecutive 20-s VO2
mean values attained toward the end of the test.
Before the second trial, subjects were randomly assigned to
high energy drink (NP) or placebo (PLA). Either drink was
administered 40 minutes before the testing session. Men and
woman were equally represented in both groups. NP is com-
mercially marketed as pre-workout energy drink (Ultimate
Nox-pumpTM, Dorian Yates Ultimate Formulas Ltd, Los
Angeles, USA) consisted 15 g of a powder conta ining 6000 mg
of carbohydrates (fructose, ribose, sucralose), 1500 mg of
L-carnitine, 2000 mg of amino acids (trimetylglicine, choline,
N-acetyl-L-tyrosine, L-phenylalanin), 3800 mg of creatine, 500
mg of taurine, 350 mg of glucuronolactone, 150 mg of caffeine,
200 mg of B vitamins , and mixed with 250ml of water. The
nutritional composition per serving of the supplement was 49
calories. Placebo consisted of an equivalent amount of cellulose
mixed with water. Beverages were administered in uniform
containers and identifiable only by numeric code to both the
investigators and the subjects.
Statistical Analysis
The data are expressed as means (SD). Statistical sig-
nificance was assessed using Student’s t test for correlated
samples. Two-ways analysis of variance with repeated mea-
sures was used to assess changes in exercise performance
indices between groups over time. Statistical significance was
set at p < 0.05. Data were analyzed using SPSS software
(version 13.0; SPSS, Inc., Chicago, IL).
All results are shown in Table 2. There were no significant
differences in strength, CMJ, VJ and VO2max within or between
trials (p > 0.05). Significant difference in HRmax and HRR
were observed in experimental group between trials (p < 0.05;
Table 2), with mean change of 3,1 and 8,3 beats/min,
respectively. No significant difference in HRmax, HRR were seen
in placebo group between trials. Endurance (END) signi ficantly
increased in experimental group (p < 0.05) after supple-
Table 2.
Results of physiologica l tests during the study.
Nox-pump (n = 10) Placebo (n = 10)
Variables Trial 1 Trial 2 Trial 1 Trial 2
Hand grip strength (kg) 83.80 ± 27. 32 83.80 ± 26. 03 82.00 ± 28. 39 81.60 ± 28.50
CMJ (cm) 30.67 ± 5.47 32.01 ± 5.02 31.11 ± 7.94 31.71 ± 7.96
VJ (cm) 36.73 ± 6.44 38.36 ± 6.67 37.67 ± 9.18 38.00 ± 9.39
VO2max (ml/kg/min) 44.74 ± 4.91 46.14 ± 4.01 43.18 ± 7.18 43.41 ± 8.15
HRmax (beats/min) 190.5 ± 9.61 193.6 ± 9.93*† 194.5 ± 9.55 193.1 ± 8.87
HRR (beats/min) 151.8 ± 9.36 160.2 ± 11.01*† 161 ± 9.97 158.6 ± 15.94
END (sec) 546 ± 90.54 594.00 ± 76.48*† 501 ± 91.83 505.5 ± 83.15
Note. Values are means ± SD. CMJ - Countermove ment jump; VJ - Verti cal j ump; VO 2max - maximal oxygen consumption; HRmax - maximal heart rate; HRR - recovery
heart rate. * Indicates significant difference trial 1- versus trial 2 at p < 0.05; † signif ica nt di ffere nce n ox- pump vs. placebo at p < 0.05.
mentation as compared with initial results (p < 0.05), with
mean change of 48s. END was similar within the Placebo group
at pre- and post-supplementation trials (p > 0.05). Finally,
significant difference between groups over time was observed
in HRmax, HRR and END. There were no side effects reported
from the exercise testing or high energy drink ingestion.
The results of the study indicate that the pre-exercise high
energy drink does enhance exercise performance by improve-
ment in endurance performance represented by the time to
exhaustion (END). In addition, higher maximal heart rate
(HRmax) and slower heart rate recovery (HRR) after endurance
test, evidenced by higher values of recovery heart rate one
minute after exercise, were obtained. Results showed no
significant improvement in anaerobic performance indices.
Carbohydrate ingestion within 60 minutes prior to exercise
has been reported to have a negative or positive effect on
endurance exercise performance, depending on carbohydrate
content of the supplement. Furthermore, if carbohydrate-rich
supplement is consumed, as was the case in our study, decline
in endurance performance should be expected, (Coombes &
Hamilton, 2000). The rise in blood glucose concentration
causes a peak in insulin-blood concentration at the beginning of
exercise, with consequent extraordinary high muscle glucose
uptake-rate during the performance. However, this mechanism
have been proved detrimental for long term endurance
performance ( 1 hour), with substrate availability unlikely to
play a significant role in exercise performance lasting 30
minutes (Kuipers et al., 1999). Amino-acids are usual high
energy drink ingredient, proposed to enhance post exercise
recovery. This is linked with enhanced magnitude of protein
synthesis after the session, with additionally improved effect if
combined with carbohydrate (Wolfe, 2006). However, acutely
ingested amino acids are not known to have any effect on acute
exercise performance (Hoffman et al., 2008). Majority of stud-
ies suggested that creatine supplementation is effective for im-
proving performance in high-intensity exercise tasks, with no
evidence of any affect on endurance running performance
(Tarnopolsky et al., 2005). The performance-enhancing effects
of Cr have been attributed to several factors, including
improved Cr phosphate (CrP) resynthesis, increased buffering
capacity, and greater shuttling of mitochondrial ATP into the
cytoplasm (Bemben & Lamont, 2005). However, creatine
loading scheme,with 20 to 30g/day for 3 days all longer, must
be conducted in order to obtain ergogenic effects (Demant, &
Rhodes, 1999). Considering that acutely ingested amino acids
and creatine are not known to have an effect on acute exercise
performance, improved exercise performance in our study is
likely the result of the high energy compounds (e.g. caffeine,
taurine and glucuronolactone) found in the high energy drink.
Although the design of this study does not permit isolation of
the cause of the ergogenic effect, it seems that mechanism
underlying performance enhancement could be mostly
attributed to ergogenic effect of caffeine. Ergogenic potential of
caffeine has been studied extensively, with most of data
supporting the ingestion of caffeine to augment endurance for
long term exercise activities. In addition, studies that have
examined pre-exercise caffeine’s ingestion effects on endurance
in short-term exercise reported considerable variability within
studies, with general finding that caffeine either has positive
effects or causes a nonsignificant improvement in exercise time
(Mohr et al., 2008; Graham, 2001; Cox et al., 2002; Meyers &
Cafarelli, 2005; Slivka et al. 2008). Limited data considering
caffeine ingestion effects on progressive exercise protocol
performance have been published. Perkins et al. (1975)
reported no effects of caffeine ingestion on time to exhaustion.
However, several authors, (Dodd et al., 1991; Powers et al.,
1983; Flinn et al., 1990), showed small (0.3 and 0.5 minutes) or
significant (from 14.9 to 17.5 minutes) increase in endurance
time after caffeine intake.
Caffeine has been proposed to improve exercise performance
by 1) increasing mobilization of fat and possible sparing of
muscle glycogen, 2) affecting calcium release from the sar-
coplasmic reticulum, and 3) increasing excitatory neuron-
transmitter activity as a consequence of adenosine receptor
antagonism. (Spriet, 2002). Considering that exercise
performance in this study is not limited by carbohydrate
availability, other mechanisms must explain its ergogenic effect.
Caffeine administration could influence high intensity short
term performance by increasing intracellular calcium concen-
tration (Doherty et al., 2004). It should be noted, however, that
these effects occurred during in vitro (James et al. 2004) or in
vivo experiments (Powers et al., 1983) with either above toxic
level caffeine doses, or caffeine concentrations that are not
regularly observed in high energy drinks (> 7 mg/kg). Thus it is
likely that ergogenicity of caffeine in this study is the result of
its role as an adenosine receptor antagonist (Graham, 2001).
Recent researches imply that caffeine affects endurance per-
formance largely through its antagonist effect on adenosine
receptors in the brain (Davis et al., 2003) modulating central
fatigue and ratings of perceived exertion (RPE). Indeed, one
consistent outcome of caffeine ingestion during exercise testing,
regardless of intensity, or duration of exercise, is an alteration
in participants’ perceptual response. A recent study (Doherty &
Smith 2005) revealed that caffeine appears to reduce rates of
perceived exertion (RPE) during exercise, by an average of 7%.
Althouth RPE was not monitored in our study, it could be
hypothesized that reduction in RPE at all levels of intensity
enables experimental group–subjects to sustain higher power
outputs and consequently improve time to exhaustion during
pseudo ramp test protocol. Finally, results across studies
suggest that caffeine dose found in high energy drink used in
this study (150 mg/l) could be effective for increasing exercise
performance in recreationally active subjects. Although
caffeine is the main purported ergogenic ingredient this
commercially available energy drink also contains other
potential ergogenic compounds. For example, taurine supple-
mentation has been shown to increase exercise
time-to-exhaustion, with doses of 2-6 g/day for one week sug-
gested to be beneficial (Zhang et al., 2004). For the present
study, the amount of taurine (500 mg) with just pre-exercise
administration, may have been too low to elicit an improvement
in endurance performance. No studies appear to have examined
the effect of glucuronolactone ingestion on exercise
performance. However, when ingested with taurine and
caffeine, it has been shown to improve cognitive function,
alertness, and physical performance (Alford et al., 2001). In
addition, the B vitamins are known to play an important role in
energy metabolism (Manore, 1994). Additional researches are
warranted to determine the contributions of each ingredient to
exercise performance.
The results of this study support the use of high energy drink
before exercise in order to improve endurance performance in
recreationally active subjects There are several possible mecha-
nisms that could account for this improvement, with suggested
high energy compound effect on CNS most likely responsible.
In effort to substantiate or refute the findings of this research,
additional studies are warranted.
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