R E S E A R C H A R T I C L E Open Access
Ubiquinol supplementation enhances peak power
production in trained athletes: a double-blind,
placebo controlled study
, Michael E Schmidt
and Stefan C Siebrecht
Background: To investigate the effect of Ubiquinol supplementation on physical performance measured as
maximum power output in young and healthy elite trained athletes.
Methods: In this double-blind, placebo-controlled study, 100 young German well trained athletes (53 male, 47
female, age 19.9 ± 2.3 years) received either 300 mg Ubiquinol or placebo for 6 weeks. Athletes had to perform a
maximum power output test and the performance in W/kg of bodyweight was measured at the 4 mmol lactate
threshold on a cycling ergometer before the supplementation treatment (T1), after 3 weeks (T2) and after 6 weeks
(T3) of treatment. In these 6 weeks all athletes trained individually in preparation for the Olympic Games in London
2012. The maximum power output was measured in Watt/kilogram body weight (W/kg bw).
Results: Both groups, placebo and Ubiquinol, significantly increased their physical performance measured as
maximum power output over the treatment period from T1 to T3. The placebo group increased from 3.64 ±
0.49 W/kg bw to 3.94 ± 0.47 W/kg bw which is an increase of +0.30 ± 0.18 W/kg bw or +8.5% (±5.7). The Ubiquinol
group increased performance levels from 3.70 W/kg bw (±0.56) to 4.08 W/kg bw (±0.48) from time point T1 to T3
which is an increase of +0.38 ± 0.22 W/kg bw or +11.0% (±8.2). The absolute difference in the enhancement of the
physical performance between the placebo and the Ubiquinol group of +0.08 W/kg bodyweight was significant
(p < 0.03).
Conclusions: This study demonstrates that daily supplementation of 300 mg Ubiquinol for 6 weeks significantly
enhanced physical performance measured as maximum power output by +0.08 W/kg bw (+2.5%) versus placebo in
young healthy trained German Olympic athletes. While adherence to a training regimen itself resulted in an
improvement in peak power output, as observed by improvement in placebo, the effect of Ubiquinol
supplementation significantly enhanced peak power production in comparison to placebo.
Keywords: Ubiquinol, Reduced CoQ10, Peak power output, Performance, Elite athletes
Coenzyme Q10 (CoQ10) is synthesized in the human
organism and is a fat soluble, vitamin-like substance
which can exist as Ubiquinone (oxidized CoQ10) or as
Ubiquinol (the unoxidized, reduced form). It plays vari-
ous roles in the energy production of the muscles’cells.
The concentration of the coenzyme in the tissue can
decline, and thus be suboptimal, as a consequence of
different pathological changes. In addition, additional
factors that can negatively influence CoQ10 levels in-
clude intensive training and aging. Long lasting and in-
tensive efforts by sport training likewise contribute to
this reduction. Some existing studies have already shown
that CoQ10 can mitigate muscle damage after high level
training . Previous studies have been conducted utiliz-
ing differing dosage levels of CoQ10 and have shown
conflicting results. Coenzyme Q10 was previously con-
sidered to be an ineffective substance for athletes, as
past studies with CoQ10 did not give consistent results.
This may have been caused by the study design or by an
insufficient dosage of CoQ10.
* Correspondence: email@example.com
Health Ingredient Consultant, Gustavstr. 36, Schwelm 58332, Germany
Full list of author information is available at the end of the article
© 2013 Alf et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Alf et al. Journal of the International Society of Sports Nutrition 2013, 10:24
Energy production in mitochondria via CoQ10 and
CoQ10 is an integral component of the mitochondrial
oxidative phosphorylation system, where it serves as an
essential carrier of reducing equivalents in electron
transport. Oxidative phosphorylation harnesses energy
from nutrients to produce ATP, the energy in each of
our cells and all of our life processes. CoQ10 is critical
for the synthesis of ATP, as 96% of all aerobically pro-
duced energy involves CoQ10. Though it is endogen-
ously synthesized, a small amount of CoQ10 is always
degraded and thus must be replenished from dietary
sources. Organs like the heart and muscles, which re-
quire consistent and robust bioenergetics, depend on a
sufficient supply of CoQ10 and produce less energy and
strength if they are deficient in CoQ10.
Antioxidant function of CoQ10 and Ubiquinol in cell
CoQ10 is the most important lipid soluble antioxidant
in the body along with vitamin E. They are structurally
linked to one another and both are part of the cell mem-
branes which they protect from deleterious radicals. In
fact, CoQ10 in the Ubiquinol form is depleted before
vitamin E, as it reacts first with radicals and is destroyed
by them . CoQ10 in the Ubiquinol form is a potent
antioxidant that has the capacity to protect Vitamin E,
and also helps to regenerate depleted vitamin E and
Vitamin C. Oxidized CoQ10 (ordinary CoQ10) must
first be converted to the Ubiquinol form in order to
exert this antioxidant effect. CoQ10 should not be com-
pared with the multitude of water soluble antioxidants,
which move freely in the blood and have a rather non-
specific effect. Along with vitamin E, CoQ10 has the
special task of protecting the very sensitive cell mem-
branes and this gives it a unique position amongst all
Studies have shown that the reduced form of CoQ10
known as Ubiquinol is 6–10 times more bioavailable than
oxidized CoQ10 [3,4]. Plasma levels of 6–8μg/ml plasma
can be achieved in humans with 300 mg Ubiquinol .
With 450 –600 mg Ubiquinol, CoQ10 plasma levels of
8–10 μg/ml plasma can be achieved . Studies are
currently underway, also with trained elite athletes in
Germany, to determine whether athletes in particular can
benefit from such elevated CoQ10 plasma levels.
The optimal plasma level for athletes is not known to
date. It appears that athletes need more CoQ10 due to
their higher metabolic requirement, and CoQ10 supple-
ments may benefit them by increasing their plasma and
muscular CoQ10 levels. The necessary and effective
dosages for athletes remain unknown yet. A typical
plasma level of 1 μg CoQ10 per milliliter of plasma
may not be enough to optimize physical performance.
Previous studies have shown that only athletes with a
CoQ10 Plasma level greater than >2.5 mg/L (=2,5 μg/ml)
or more showed an increase in physical performance. Ath-
letes want to get the highest possible CoQ10 plasma levels
of greater than >3.5 mg/L (=3,5 μg/ml) .
Despite de novo synthesis of CoQ10, it appears to be
lost during the sustained exertion required in sports
training. Trained athletes often have lower CoQ10
plasma levels than untrained people . Heavy training
and exercise leads to a decrease in plasma levels of
athletes . The athletes had lower plasma levels during
periods of heavy training than in training free periods
. This may be caused by different mechanisms. Ath-
letes appear to have a higher metabolic requirement of
CoQ10, which is not compensated by normal food in-
take and biosynthesis in the body. Highly trained ath-
letes can therefore exhibit lower CoQ10 levels in tissue
and blood, and this can limit their performance. So it is
especially important for athletes to monitor their CoQ10
plasma level and to supplement their CoQ10 as neces-
sary. To date, there is no recommended CoQ10 plasma
level for athletes. But the latest studies show a link be-
tween the CoQ10 plasma level and performance cap-
acity: the higher the CoQ10 plasma level, the higher the
performance capacity. Higher CoQ10 plasma levels may
translate into higher CoQ10 levels in muscles and liver.
Kon et al.  demonstrated that CoQ10 supplementa-
tion increased total CoQ10 concentration significantly in
slow-twitch muscles (soleus and gastrocnemius deep
portion) and liver. Additionally, plasma creatine kinase
was significantly decreased after exercise by CoQ10 sup-
plementation as opposed to placebo. Coenzyme CoQ10
deficiency in athletes could be triggered by:
Increased consumption and increased requirement
for CoQ10 due to sustained, heavy physical exertion
Reduced CoQ10 uptake due to vegetarian diet
Limited CoQ10 biosynthesis due to deficiencies of
nutrients like selenium, vitamin B6, magnesium etc.
Intake of high doses of vitamin E inhibits CoQ10
uptake from food and lowers the CoQ10 plasma
Statin therapies limit CoQ10 biosynthesis and
deplete the CoQ10 plasma level
Normally, training can increase the number of mito-
chondria in heart and muscles. The mitochondria are
rich in CoQ10 and therefore training also increases the
CoQ10 content in heart and muscle . Training also
increases the biosynthesis of CoQ10 and therefore there
is also a higher requirement for ingredients that are
needed for the CoQ10 biosynthesis. On the other hand,
the mitochondria normally do not reach the CoQ10 sat-
uration level . This practically means that at the
Alf et al. Journal of the International Society of Sports Nutrition 2013, 10:24 Page 2 of 8
actual concentrations of CoQ10 in these membranes the
velocity of the respiratory complexes is not the maximal
one. There is still capacity to increase the CoQ10 con-
tent in the mitochondria, and this could explain the in-
crease of maximal oxygen uptake (VO2-max) by CoQ10
supplementation . Heavy physical training leads to a
decrease in plasma CoQ10. Plasma CoQ10 is inversely
correlated to the intensity of training or exercise.
The muscle CoQ10 content is linear dependent on the
content of Type I, oxidative muscle fibers . In a
study by Fiorella and Bargossi , the CoQ10 Plasma
level increased less after supplementation when the
athletes exercised heavily. It seems that the CoQ10 in
the plasma is immediately absorbed by the exercising
muscle. Exercise may stimulate the muscular uptake of
CoQ10 from the plasma.
CoQ10 dosage for athletes
In animal models, administration of CoQ10 has shown
an increase in CoQ10 concentrations in organs, in par-
ticular the heart and muscle. In these studies it was also
shown that CoQ10 supplementation also increased Vita-
min E content in heart muscle and liver .
In humans, a dosage of 120 mg CoQ10 given to ath-
letes was unable to increase the muscle CoQ10 content
. To increase the human muscle CoQ10 content, it
is necessary to increase the CoQ10 plasma to a greater
extent over a longer period of time, so that the muscle
tissues have enough time to absorb the CoQ10 from the
plasma. Higher dosages of 200–300 mg CoQ10 or more
of Ubiquinol per day over a 4–12 week period is needed
to increase muscle CoQ10 content. In one trial, 200 mg
CoQ10 supplementation for 14 days lead to a trend of in
increased muscle CoQ10 content . Based on these
observations, 100 mg CoQ10 per day for athletes may be
insufficient to achieve any enhancement in performance.
Indeed, earlier studies were likely unsuccessful because
of inadequate dosing, resulting in suboptimal CoQ10
plasma levels. In an earlier Italian study, a dosage of
100 mg CoQ10 per day only increased the plasma level
to a value of 1.34 μg/ml , which is too low to achieve
any effects for athletes.
In a later Italian study the same 100 mg dose raised
the CoQ10 plasma level to 2.23 μg/ml.
After 2 months of CoQ10 supplementation, greater
exertion was required to induce exhaustion and overall
performance improved. Another study found the dose of
100 mg CoQ10 exerted no effect, but a 300 mg dosage
of CoQ10 and raising plasma level to 3.29 μg/ml signifi-
cantly increased endurance and protected against ex-
haustion in a maximum speed test on the ergometer
. In a crossover study of 15 cyclists in which each
participant received both 300 mg of CoQ10 and placebo,
each for four weeks in random order, a moderate to
strong correlation between the significant increase in total
blood CoQ10 and total workload was observed . Given
the small sample size and the crossover study design that
administered CoQ10 at different phases of the athletes’
overall training regimen, the correlation between total
blood CoQ10 and performance improvement suggests
that a sufficiently powered study with a traditional
placebo-controlled design where the 300 mg dosage was
administered for at least four weeks or more could evalu-
ate whether CoQ10 affects performance output.
Based on the available data, it appears that the CoQ10
dosages in earlier studies were insufficient to achieve
any significant positive results for athletes. Clinical
studies with athletes are increasingly proving positive
effects for a dosage of 300 mg CoQ10 or CoQ10 plasma
levels >3.3 μg/ml. With Ubiquinol, the reduced form of
CoQ10, higher CoQ10 plasma levels can be achieved
with lower dosages than with oxidized CoQ10 which
might be metabolically superior. This study extends the
findings of previous studies by enrolling a study popula-
tion with greater statistical power and administering
either CoQ10 at 300 mg daily or placebo for six weeks
to elite athletes in a variety of sports at a similar stage in
their training regimen in preparation for the Olympic
Games of 2012.
One hundred subjects (gender of the athletes: 53 males
and 47 females) were recruited among the young
German athletes training regularly at the Olympic Train-
ing Camp Rhein-Ruhr in Essen, many of whom are dir-
ectly competing at the Olympic Games 2012 in London.
No monitoring or control of diet (e.g., fasting) was im-
posed on study participants to mimic the circumstances
under which supplements are typically ingested by ath-
letes, both elite and recreational. This investigation
sought to compare the performance effect of 50 athletes
on Ubiquinol supplementation versus 50 other athletes
who received placebo capsules.
All athletes received 5 brown colored liquid filled hard
gelatin capsules every day. These capsules contained
either lactose in medium chain triglycerides (MCT) Oil
(placebo group) or 60 mg Ubiquinol in MCT oil
(KanekaQH) per liquid filled hard gelatin capsules cap-
sule. The liquid filled hard gelatin capsules were pro-
duced by Capsugel (Colmar, France). The athletes came
from the training pool of the following respective sports:
canoe, rowing, swimming, hockey, golf, track and field.
At study entry the athletes were randomly assigned to
receive liquid filled hard-gelatin capsules containing
Ubiquinol or placebo. The average age of the tested
people was 19.2 years (±2.3 years). The average height
was 181 cm (±10.5 cm) and the average weight 78 kg
Alf et al. Journal of the International Society of Sports Nutrition 2013, 10:24 Page 3 of 8
The performance is expressed in Watts per kilogram
body weight (W/kg bw), and measured at the beginning
of the Ubiquinol supplementation and of the placebo
group, after 3 weeks and after 6 weeks. Lactate levels
were checked in parallel with blood samples. The tests
were performed on the IAS 150 from the company
Ergoline, which measures Watt performance. Based on
performance time, the work load per kg of body weight
was calculated (W/kg bw).
Physical performance is usually measured by a gradual,
continuous or intermittent shaped rising stress test during
spirometry determined on a bicycle or treadmill [20-22].
The data were derived from a placebo-controlled, ran-
domized, two-arm study which was initiated to investi-
gate the effect of Ubiquinol in improving the physical
fitness of trained athletes (a total of 100 young healthy
athletes, ratio of control to experimental subjects = 1:1,
n = 50 in experimental and n = 50 in control group, re-
spectively). The physical performance of the athletes was
measured at three different time points (T1, T2, T3) in
watts per kilogram of body weight (W/kg bw). The pri-
mary endpoint of the study was defined as the difference
of the mean fitness increase of both groups measured
from time point T1 to time point T3.
After determining the individual fitness increase from
time point T1 to time point T3 the significance of the
difference of the group means (experimental: mean =
0.38, standard deviation = 0.22; control: mean = 0.24,
standard deviation = 0.34) was calculated using a Stu-
dent’st-test for independent samples and pooled vari-
ances. The test statistic revealed significant differences
between the control and experimental groups with a
p-value of 0.018 on an error level of α= 0.05.
The variables set included the fitness measurements at
the time points T1, T2, and T3 as well as the subject
identification number. In the univariate analysis, line
graphs depict the individual’s fitness level at different
time points throughout the study and the fitness means
of both groups including one standard deviation. Histo-
grams are used for screening of outliers, checking nor-
mality, or suggesting another parametric shape for the
distribution. The two-sided Student’st-test for independ-
ent samples and pooled variances was applied for testing
the statistical significance of the difference between the
mean fitness increases of the two groups based on
log-transformed values. The Fisher’s F-test was used to
compare two variances. The goodness of fit of the
sample to a normal distribution was assessed using the
Kolmogorov-Smirnov test and Q-Q plot (not shown).
Finally, a linear mixed-effects model was fitted simul-
taneously to all measurements of both groups. The stat-
istical testing’s were conducted using an exploratory
approach, the maximum type I error probability associ-
ated with all statistical tests in the analyses is 0.05. The
biometric analyses were performed with the statistical
programming environment GNU R, version 2.14.0, and
the post hoc power analysis was computed using PS
Power and Sample Size Calculations, version 3.0.
Results and discussion
The individual fitness levels measured in Watt/kg
bodyweight at time points T1, T2 and T3, and stratified
by study group, are illustrated in Figure 1. As one can
see from the graph, two athletes of the control group
show normal increases of their values at time point T2,
but are followed by implausible deep declines at time
point T3. The drop in physical performance was due to
an infection, therefore the two individuals are considered
to be protocol non-compliers, and the corresponding re-
cords are dropped from computations, otherwise these
two data would have had a quite negative impact of the
performance of the placebo group and would have cre-
ated a wrong and too positive difference in performance
towards the Ubiquinol supplement group. Thus, in total
n = 50 athletes of the experimental group and n = 48 ath-
letes of the control group finally remained for further
The arithmetic means of the power output measure-
ments increased from 3.70 W/kg bodyweight (±0.56) at
time point T1 to 4.08 W/kg bodyweight (±0.48) at time
point T3 in the experimental group and from 3.64 W/kg
bw (± 0.49) to 3.94 W/kg bw (±0.47) in the control
group, respectively (Figure 2). This corresponds to mean
differences between the time points T1 and T3 of
0.38 W/kg bodyweight (±0.22) in the experimental group
and of 0.30 W/kg bodyweight (±0.18) in the control
group. Accordingly, the mean percentage increases at
time point T3 calculated with respect to time point T1
are 11.0% (±8.2) in the experimental (ubiquinol) group
and 8.5% (±5.7) in the control (placebo) group. For both
study groups, the calculated statistical parameters are
summed up in Table 1.
Before performing tests of significance, a log-trans-
formation of the computed fitness differences between
time point T1 and time point T3 was applied to make
the variable’s distribution closer to normal. Hence, no
significant deviation from the normal distribution could
be detected (Kolmogorov-Smirnov test: experimental
p = 0.995, control p = 0.381), and the variances were
homogenous (F-test: p = 0.112), which is considered to
be a precondition for performing a t-test. The t-test
revealed a significant difference of the mean fitness
Alf et al. Journal of the International Society of Sports Nutrition 2013, 10:24 Page 4 of 8
Figure 1 Individual physical fitness by time point and study group. Individual performance output measured in W/kg bw at time points T1,
T2 and T3, stratified by placebo group (Control group) and Ubiquinol group (Experimental group).
Figure 2 Mean Measured fitness by time point and study group. Progress of fitness (absolute values in W/kg bw and percentage values) at
time points T1, T2 and T3 plotted as means and one standard deviation, stratified by study group.
Alf et al. Journal of the International Society of Sports Nutrition 2013, 10:24 Page 5 of 8
increases between experimental and control groups
(p = 0.03).
A linear mixed effects model was used to analyze the
resulting figures, controlling for time and group effects.
The model includes the fitness values in Watt per kg
bodyweight on the original scale as response variable,
with repeated measurements at time points T1, T2, T3
and study group as fixed factors. The number of the ath-
letes was added to the model as a random variable to ac-
complish an individual level estimation. Time point T1
and the control group were used as reference category.
The parameter estimates for the predictor variables were
obtained using restricted maximum likelihood technique
with stepwise forward selection. The results of the main
effect analysis indicate a highly significant influence of
training time regarding progress of physical fitness (T2
and T3 p < 0.001). Furthermore, the interaction between
study group and time point T3 is noticeably significant
(p = 0.010). Thus, multivariate analysis also demonstrates
that both study groups experienced a substantial in-
crease in physical fitness. However, this training effect is
significantly more apparent in the experimental group
(Ubiquinol supplementation) than in the control (pla-
Among these 100 young and healthy elite German
Olympic athletes, a continuous increase of physical fit-
ness was observed in the Ubiquinol supplemented group
as well as in the control group during the study course,
expressed in absolute values or in percentage units. This
effect is attributed to the individual physical training
program of each athlete, and matches the expectation.
However, the objective of the study was to investigate to
what extent the effect of physical training can be
positively influenced by additional intake of 300 mg
Ubiquinol daily for six weeks as a dietary supplement.
Based on the available data, the results of the study sug-
gest that Ubiquinol may have positively impacted the
observed elevated level of training success, a fact that
was statistically significant for absolute differences and
in multivariate analysis but slightly missed the signifi-
cance level using percentage values. However, the nu-
merical difference between experimental and control
groups regarding the effect of Ubiquinol might be
regarded as relatively small, but this can make a very
significant difference for elite athletes.
Elite athletes are training on such a high level that per-
formance enhancements often fail to impart any add-
itional ergogenic benefit. In other studies for example it
was shown that caffeine can increase mean power out-
put in a similar range as we found here for Ubiquinol. In
one double blind, randomized crossover study, a supple-
mentation with 6 mg or 9 mg caffeine per kg body
weight increased performance by +2.7% (+0.4 to +5.0%)
and decreased performance time in rowers 2000-m dis-
tance by −1.2% (−0.4 to −1.9%) vs placebo . The used
dosage in this study is quite high and bears some health
risks especially for the cardiovascular system. Both doses
of caffeine had a similar ergogenic effect relative to pla-
cebo. So there is no benefit of consuming more caffeine,
but the negative side effects of caffeine are increasing.
The magnitude of the performance enhancement is
already achieved by 3 mg caffeine per kg bodyweight
and was found to be around +0.4 to +5% in different
Though caffeine generally accepted as an ergogenic
aid, it was on the official doping list for decades and
banned since 2004. Because high caffeine consumption
may cause serious side effects especially for athletes, the
World Anti-Doping Agency is considering banning caf-
feine again to avoid potential health risks for athletes.
Nutrients such as Ubiquinol are a safe and healthy alter-
native to caffeine as on one hand it supports and in-
creases physical performance of the athletes in a similar
range like caffeine and secondly is also beneficial for the
health of the athletes, especially for the heart. Addition-
ally, Ubiquinol may in particular benefit the antioxidant
status of athletes which often compromised by the ele-
vated presence of reactive oxygen species.
The results of the test statistics have been advanta-
geously affected by the small variability of increase of
physical fitness among the two study groups despite the
range of intensity of physical activity inherent to the
Table 1 Summary Statistics
Parameter Experimental group
N Mean 95% CI Std Min Med Max
T1 50 3.70 3.54-3.86 0.56 2.14 3.77 4.88
T2 50 3.81 3.66-3.96 0.53 2.65 3.90 4.92
T3 50 4.08 3.94-4.21 0.48 2.85 4.24 4.99
Diff. abs. T1-T3 50 0.38 0.32-0.44 0.22 0.07 0.34 1.13
Diff. perc. T1-T3 50 11.03 8.71-13.55 8.16 1.62 8.58 41.09
Parameter Control group
N Mean 95% CI Std Min Med Max
T1 48 3.64 3.50-3.78 0.49 2.42 3.86 4.28
T2 48 3.75 3.60-3.89 0.49 2.72 3.89 4.38
T3 48 3.94 3.80-4.07 0.47 2.80 4.08 4.52
Diff. abs. T1-T3 48 0.30 0.25-0.35 0.18 0.03 0.28 0.76
Diff. perc. T1-T3 48 8.54 6.89-10.20 5.70 0.84 7.20 21.97
Summary statistics of the measured fitness in W/kg bw at time points T1, T2
and T3, and the fitness increases expressed as absolute (Diff. abs.) and
percentage values (Diff. perc.) including number of probands (n), arithmetic
mean (Mean), 95% confidence limits of mean (95% CI), standard deviation
(Std), minimum (Min), median (Med) and maximum (Max), stratified by
Alf et al. Journal of the International Society of Sports Nutrition 2013, 10:24 Page 6 of 8
sports in which each athlete was training (e.g., golf vs.
track and field). The plot of the individual performance
output (Figure 1) suggests that individuals exist in
the experimental group who benefitted more from an
Ubiquinol supplement compared to others. Two partici-
pants of the control group were initially excluded from
the analysis. If these two participants had remained in
the study, the effect differences between the two study
groups would have been larger, resulting in considerably
higher statistical significance. Further insight could be
provided, if the enhancement of performance output
could be correlated with other biological parameters, e.g.
the individual Ubiquinol plasma levels of the athletes.
Future studies might benefit from being designed to pro-
vide CoQ10 at individualized doses that achieve a
consistent range of plasma Ubiquinol concentration.
Physical training leads to an increase in muscle mass
and also to an increase in mitochondria containing Q10.
Increased demand for Q10 by muscle could explain why
plasma Ubiquinol levels have been observed to decrease
in trained athletes [6,7].
Certain data measured in previous studies (e.g., plasma
Ubiquinol concentration and oxidative stress) were not
collected in this study due to lack of available funds to
perform these relatively expensive assays multiple times
in a study population of 100. Another consideration in
the choice not to measure oxidative stress was that its
link with physical performance has not been established.
The goal of this study was to focus on CoQ10’s energetic
effects and not on its antioxidant properties. Another
difference between this study and some previous studies
is the lack of control or monitoring of dietary intake;
however, Q10 intake via food consumption ranges be-
tween 5–10 mg per day, a level that is insignificant rela-
tively to the administered dose of 300 mg per day. So,
while there may have been variance among study partici-
pants with regards to diet, oxidative stress, and plasma
concentrations of Ubiquinol, such variances were insuffi-
cient to negate the statistical significance of the findings on
CoQ10’s effects on physical performance as reported here.
In this study, CoQ10 supplementation resulted in in-
creased short term maximum performance, which im-
plies anaerobic output, perhaps via an increase in ATP
and creatinine phosphate synthesis. An alternative ex-
planation is that CoQ10 supplementation could work via
a direct increase in muscular Q10 levels, suggesting
that aerobic energy conversion might be improved by
inhibiting ammonia production from AMP. When ATP
levels decrease during exercise, 2 ADP are converted
into ATP and AMP. Higher mitochondria activity pro-
duces more continuous ATP and a higher level on
Ubiquinol in the mitochondria contributes to increased
ATP synthesis. Such mechanisms are consistent with the
observation of improved performance with CoQ10
supplementation over a study population that included
both endurance and strength athletes.
Older athletes and “weekend warriors”might profit
even more from CoQ10 supplementation than young,
well-trained athletes. Aging reduces the number of mito-
chondria and the level of Q10 in all tissues decreases
with age. Increasing the Q10 content of remaining mito-
chondria might at least partly compensate for the lower
number of mitochondria. Untrained athletes’muscles
are not as adapted to changing energy needs during
exercise as are those of elite athletes. Other supplements
have elicited stronger effects in increasing physical per-
formance in recreational athletes and CoQ10 might be
another such example.
This study demonstrates that daily supplementation of
300 mg Ubiquinol for 6 weeks significantly enhanced
physical performance measured as maximum power out-
put by +0.08 W/kg bw (+2.5%) versus placebo in young
healthy trained German Olympic athletes. While adher-
ence to a training regimen itself resulted in an improve-
ment in peak power output, as observed by improvement
in the placebo group, the effect of Ubiquinol supplementa-
tion significantly enhanced peak power production in
comparison to placebo.
ATP: Adenosine triphosphate; CoQ10: Coenzyme Q10; kg: Kilogram; l: Liter;
μg: Microgram; mg: Milligram; mL: Milliliter; T1: Timepoint prior to
supplementation treatment (either experimental or control); T2: Three weeks
after initiation of supplementation treatment; T3: Six weeks after initiation of
supplementation treatment; VO2-max: Maximal oxygen uptake or maximal
aerobic capacity; W/kg bw: Watt/kilogram body weight.
The study was funded by the companies and Capsugel an Kaneka Pharma
DA carried out the study and collected the data, MS made all the statistical
calculations, SS participated in the sequence alignment and drafted the
manuscript. All authors read and approved the final manuscript.
Olympiastützpunkt Rhein –Ruhr, Wittekindstrasse 62, Essen 45131, Germany.
Biostatistics, Roentgenstr. 25, Planegg 82152, Germany.
Consultant, Gustavstr. 36, Schwelm 58332, Germany.
Received: 30 July 2012 Accepted: 22 April 2013
Published: 29 April 2013
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Cite this article as: Alf et al.:Ubiquinol supplementation enhances peak
power production in trained athletes: a double-blind, placebo
controlled study. Journal of the International Society of Sports Nutrition
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