Category Archives: coenzyme Q10

Doctor’s Best: CoQ10

What is Coenzyme Q10?

Coenzyme Q10 is a vitamin-like, fat soluble nutrient central to energy production at the cellular level, essential for generating metabolic energy in the form of ATP.

What is ATP?

ATP is the energy currency of every cell in the human body, it is necessary for not only exercise but for life. ATP is produced in the mitochondria, the power-house of cells, where Coenzymes Q10 plays its role.

CoQ10 levels and age

Unfortunately, CoQ10 levels decrease with age. A factor that may actually contribute to the aging process. It is believed that exhaustive, prolonged exercise may further deplete CoQ10 levels. Food content of CoQ10 can be very low, thus many healthcare providers recommend supplementing with Coenzyme Q10. Given CoQ10’s vital role in energy production, supplementation seems to be a wise decision for any athlete engaging in exhaustive exercise.

Clinical trials on Coenzyme Q10

Clinical trials have demonstrated Coenzyme Q10’s usefulness as an ergogenic aid, which are substances that benefit athletic performance. One study demonstrated that only 8 weeks of CoQ10 supplementation at 100mg showed performance improvement and fatigue reduction in repeated bouts of exercise compared to placebo (1).
Another study showed significant improvement in power production in elite, Olympic athletes after 6 weeks of supplementation (2).

In 2008, a clinical trial showed that CoQ 10 supplementation improved time to exhaustion for participants in only 2 weeks (3).

CoQ10 and Athletic Performance

CoQ 10’s use as an ergogenic aid extends beyond its direct improvement of performance markers, it also helps athletes deal with exercise-induced stress. Taking CoQ 10 before strenuous bouts of exercise has been shown to reduce oxidative stress and inflammatory signaling, preventing further damages to the muscles (4).

Scientific References:

  1. Gökbel H, Gül I, Belviranl M, Okudan N. The effects of coenzyme Q10 supplementation on performance during repeated bouts of supramaximal exercise in sedentary men. J Strength Cond Res. 2010;24(1):97-102.
  2. Alf D, Schmidt ME, Siebrecht SC. Ubiquinol supplementation enhances peak power production in trained athletes: a double-blind, placebo controlled study. J Int Soc Sports Nutr. 2013;10:24.
  3. Cooke M, Iosia M, Buford T, et al. Effects of acute and 14-day coenzyme Q10 supplementation on exercise performance in both trained and untrained individuals. J Int Soc Sports Nutr. 2008;5:8.
  4. Díaz-castro J, Guisado R, Kajarabille N, et al. Coenzyme Q(10) supplementation ameliorates inflammatory signaling and oxidative stress associated with strenuous exercise. Eur J Nutr. 2012;51(7):791-9.
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Clarifying CoQ10 supplements

CoQ10 (coenzyme Q10) is a naturally occurring compound, synthesised endogenously and found in small levels in an average diet. Found predominantly in the mitochondria of the cells, this important enzyme plays a key role in energy production and is vital for ensuring normal everyday functioning. In addition to its role in energy production, CoQ10 is a potent antioxidant and is also able to regenerate other antioxidants including vitamin E, vitamin C and lipoic acid. Its ability to quench free radicals is, in fact, key to maintaining the structural integrity and stability of mitochondrial and cell membranes. [1] CoQ10 levels generally peak around the age of 20-30 and decline with increasing age. Significantly decreased levels of CoQ10 are found in a wide variety of diseases, especially those associated with oxidative stress [2] as wells in individuals using statins for cholesterol management. Also known as HMG-CoA reductase inhibitors, statins treat elevated blood cholesterol levels by blocking cholesterol biosynthesis. In doing so, however, they also block CoQ10 biosynthesis, which may lead to symptoms of fatigue and muscle pain (known as statin-induced myopathy). [3]

Ubiquinone and ubiquinol

Ubiquinol
CoQ10 exists in two forms, as ubiquinone (the oxidised CoQ10, spent form) and ubiquinol (the reduced and activated, antioxidant form).

CoQ10 exists in two forms, as ubiquinone (the oxidised CoQ10, spent form) and ubiquinol (the reduced and activated, antioxidant form). In order for CoQ10 to play a role in energy production and exhibit an antioxidant effect, the body must metabolise it to its antioxidant form ubiquinol, a process inhibited with increasing age, nutrient deficiency and some health conditions. Taking CoQ10 as ubiquinone is therefore not as effective as taking CoQ10 as ubiquinol (Kaneka QH™) the ‘body-ready’ form which has only been available for use in supplements since 2006. Ubiquinol has numerous advantages over ubiquinone and comparing the two forms in therapeutic outcomes far surpasses its oxidised precursor.

Bioavailability

When addressing the issue of therapeutics, at first glance the dose of ubiquinol may seem particularly relevant; however, it is the blood plasma level achieved by supplementation that is the significant factor in determining the effectiveness of a treatment. [4] As a lipid-soluble nutrient, ubiquinol absorption and bioavailability is generally poor, with as much as 60% eliminated in the faeces. [5] Whilst the structure of ubiquinol renders it more water-soluble than ubiquinone, most common formulations of ubiquinol (found in powder form or dispersed in oil suspensions) are of relatively low bioavailability. [6] As clinical outcomes are dependent on increasing the bioavailability, solubilising ubiquinol is the only method to guarantee that therapeutically viable blood plasma levels are achieved.

VESIsorb® for unprecedented bioavailability

Ubiquinol that utilises the VESIsorb® technology offers unprecedented bioavailability to deliver plasma levels superior to all other forms of CoQ10. [7] When in contact with the aqueous contents of the stomach, this novel delivery system naturally self-assembles into colloidal droplets (micro-emulsion), engulfing the ubiquinol, which is then able to completely dissolve in water. By doing so, ubiquinol is effectively fast-tracked from the gut lumen, through the unstirred water layer barrier that lines the gut wall, directly into the enterocyte cell for immediate transfer to the circulatory system.

Igennus VESIsorb® Ubiquinol-QH

Igennus VESIsorb® Ubiquinol-QH ensures significantly higher plasma concentrations that reach therapeutic levels up to 2 times faster and are sustained for up to 6 times longer than any other delivery system or form of CoQ10. Unlike other delivery forms of CoQ10, this highly advanced delivery system achieves and maintains clinically effective plasma concentrations of CoQ10, supporting cardiovascular function, energy production, reduce the risk of neurodegenerative disease and provide potent antioxidant activity with just one 100 mg capsule daily.

References

1. Rauchova H, Drahota Z, Lenaz G: Function of coenzyme Q in the cell: some biochemical and physiological properties. Physiological research / Academia Scientiarum Bohemoslovaca 1995, 44:209-216.

2. Potgieter M, Pretorius E, Pepper MS: Primary and secondary coenzyme Q10 deficiency: the role of therapeutic supplementation. Nutrition reviews 2013, 71:180-188.

3. Watts GF, Castelluccio C, Rice-Evans C, Taub NA, Baum H, Quinn PJ: Plasma coenzyme Q (ubiquinone) concentrations in patients treated with simvastatin. Journal of clinical pathology 1993, 46:1055-1057.

4. Shults CW, Oakes D, Kieburtz K, Beal MF, Haas R, Plumb S, Juncos JL, Nutt J, Shoulson I, Carter J, et al: Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline. Archives of neurology 2002, 59:1541-1550.

5. Wyman M, Leonard M, Morledge T: Coenzyme Q10: a therapy for hypertension and statin-induced myalgia? Cleveland Clinic journal of medicine 2010, 77:435-442.

6. Bhagavan HN, Chopra RK: Coenzyme Q10: absorption, tissue uptake, metabolism and pharmacokinetics. Free radical research 2006, 40:445-453.

7. Liu ZX, Artmann C: Relative bioavailability comparison of different coenzyme Q10 formulations with a novel delivery system. Alternative therapies in health and medicine 2009, 15:42-46.

 

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Green tea and male fertility

A new study has found that an extract from green tea affects sperm quality (1). The research, published last month in the journal Molecular Nutrition and Food Research, found that low doses of a chemical compound (epigallocatechin gallate or EGCG) which is present in green tea can improve sperm quality.

Sub-fertility among men is common, and numbers of men affected are increasing. Recent data suggests that 1 in 5 men between the ages of 18-25 now have fertility problems linked to semen quality (2). In around 50% of cases, the cause of male subfertility is unknown, and in such cases nutritional and lifestyle measures are often recommended as a means of boosting sperm quality.

In this recent study, researchers exposed human sperm samples to a range of concentrations of EGCG, a chemical compound present in green tea. Results showed that, at low concentrations, EGCG was associated with increased sperm motility, viability, and phosphorylation of proteins controlling cell survival.

The aim of the study was to find out whether the extract from green tea increased the sperm’s ability to fertilise an egg by improving a process called ‘capacitation’. Capacitation is simply a series of biological processes needed to ‘activate’ the sperm so that it can fertilise the waiting egg.

At low and medium doses, the results were positive. The researchers reported that “depending on the used concentration, ECGC/estrogen receptors are able to improve fertilisation potential of the human male gamete, evidencing the specific effects on motility, viability and energy expenditure in human sperm”. In short, the sperm treated with ECGG helped sperm to swim well. It also increased the number of living sperm, and supported essential signalling inside the sperm.

coenzymeQ10
Will CoenzymeQ10 help you?

At very high concentrations, ECGC had the opposite effect. Such results highlight the need for further research in this area.

There is in fact a growing amount of research surrounding the potential benefits of nutrients in boosting male fertility, with previous studies assessing the effectiveness of nutrients such as l-carnitine and coenzyme Q10.

Previous studies support the value of antioxidants in boosting male fertility (3). The high antioxidant value of green tea is well known, and this characteristic may therefore play a role in its fertility-boosting potential. Sperm damage is thought to occur when highly reactive particles called free radicals circulate in the body, causing damage to sperm cells. This damage may reduce fertility by lowering sperm counts or reducing the sperm’s ability to fertilise an egg. For this reason, antioxidants, which fight those free radicals, are thought to be helpful.

Further controlled trials are certainly needed to provide solid guidelines on the benefits of nutrients in treating male fertility. My feeling is that further research will serve to confirm the crucial role for diet and lifestyle in this area.  The European Science Foundation recently reported new figures showing a rapid increase in male reproductive disorders. This indicates that these fertility issues are caused by environmental factors or changes in our lifestyle rather than genetic factors, meaning that they may be entirely preventable with the a natural approach focussing on nutrition and lifestyle.

Written by Nadia Mason, BSc MBANT NTCC CNHC.

References

1.De Amicis et al (2012) Epigallocatechin gallate affects survival and metabolism of human sperm Mol Nutr Food Res Nov;56(11):1655-64.

2. Male Reproductive Health – Its impacts in relation to general wellbeing and low European fertility rates. ESF Science Policy Briefing 40, October 2010.

3. Showell et al (2011) Antioxidants for male subfertility. Cochrane Database Syst Rev. Jan 19;(1):CD007411.

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Can CoEnzyme-Q10 combat statin side-effects?

A new study (1) confirms long-standing concerns about the side-effects of cholesterol-lowering statins. The study suggests that statin drugs can cause significant problems with energy levels and general fatigue, especially in women.

Statins are routinely prescribed to individuals with raised cholesterol levels and are among the most widely prescribed drugs in the UK. These drugs lower cholesterol levels by inhibiting a liver enzyme (HMG-CoA reductase) which plays a role in cholesterol production. Unfortunately this enzyme is also important for the production of Co-enzyme Q10. CoQ10 is a nutrient found in almost every cell in the body and is essential for energy production in the muscles.

The study, published in Archives of Internal Medicine, followed a group of individuals who were randomised to take one of two statins (simvastatin at 20 mg per day or pravastatin at 40 mg per day) or placebo for six months. Participants were rated at regular intervals through the study for their perceived fatigue on exertion, general fatigue and energy levels.

Overall, statins did indeed appear to cause a significant change in energy and worsen fatigue on exertion. Women were more affected than men.

In fact, 40% of the women receiving statins reported either a reduction in energy or a worsening of fatigue on exertion. 10% of the women reported that both of these issues were ‘much worse’.

Nuts contain CoQ10
Nuts contain Co-Enzyme Q10 (CoQ10) which is beneficial towards energy levels

Co-enzyme Q10 is essential for the ‘battery’ in each cell to power our muscles and organs. It is not surprising that depletion of CoQ10 can cause muscle weakness and fatigue. CoQ10 is also vital for heart function. According to one recent study (2), 71% of healthy people develop heart rhythm abnormalities when given statins.

It is important for those taking statins to be aware of the side-effects such as fatigue and muscle weakness, as these symptoms may only appear after some months or years after beginning statin treatment.

The good news is that those taking statins may be able to protect themselves from these side-effects by including good sources of CoQ10 in their diet. The richest dietary sources of this nutrient are organ meats such as liver and kidney, as these are the bodily organs that naturally store high levels of CoQ10. Other sources include oily fish, eggs, nuts and spinach.

For many individuals, dietary sources of CoQ10 may be inadequate to combat the draining effect of statins. In these cases I would recommend would be to supplementing 50 – 100 mg of CoQ10 each day.

Written by Nadia Mason, BSc MBANT NTCC CNHC

References

1. Golomb BA, et al. Effects of Statins on Energy and Fatigue With Exertion: Results From a Randomized Controlled Trial. Arch Int Med epub 11 June 2012

2. Silver MA, Langsjoen PH, Szabo S, Patil H, Zelinger A. (2004) Effect of atorvastatin on left ventricular diastolic function and ability of coenzyme Q10 to reverse that dysfunction. Am J Cardiol, 94(10):1306-10.

3. Image courtesy of Zole4

 

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CoQ10 aids male fertility

A new study involving 287 infertile men suggests that the nutrient Coenzyme Q10 improves both sperm quality and pregnancy rate.

The study, published in the International Urology and Nephrology Journal, assessed men with idiopathic oligoasthenoteratozoospermia (OAT), meaning that the men had unexplained reduced sperm count and reduced sperm quality.

CoEnzyme Q10
CoEnzyme Q10 may be useful in supporting male infertility and sperm motility

The trial measured the effects on pregnancy rate of supplementation with 300mg of CoQ10 twice a day for 12-months. Over the 12-month period, the overall pregnancy rate was 34.1%. In contrast, the pregnancy rate in non-supplemented infertile men during the same time is around 6.4%.

Sperm samples were also collected before and after supplementation. The results showed that supplementation with CoQ10 improved mean sperm concentration by 113.7%. It also improved motility (forward movement of the sperm) by 104.8% and raised the number of normal forms by 78.9%.

There are a number of reasons why CoQ10 may boost male fertility. In sperm cells, CoQ10 is concentrated in the midpiece of each sperm, acting as an energy promoting agent. The energy for movement and all other energy-dependent processes in the sperm cell depend on this crucial nutrient. CoQ10 is also an antioxidant, preventing lipid per oxidation thereby reducing damage to sperm membranes.

In cases where couples are having difficulty conceiving, it is very common for medical treatment to be focussed on the female partner only. This treatment pathway fails to address the health of the male partner which could be addressed with nutritional changes.  It does appear that couples are short-changed when they are referred for invasive medical treatments, when nutritional changes could in fact be a far less invasive and stress-free alternative. A recent review of male subfertility concluded that “The concept of unilateral care of the female partner, which has gained momentum in the reproductive health community, especially with the advent of in vitro fertilization and intracytoplasmic sperm injection, is counterproductive, and should be discouraged.”

This trial was open-label, meaning some caution is needed in interpreting the results. However, the study will hopefully pave the way for future research in this area.

While couples may not wish to rely exclusively on nutritional supplements and dietary changes to address subfertility, this approach could be used alongside medical treatment to improve chances of success. “Medical treatment with nutraceuticals helps improve sperm parameters, and even if the response is not adequate, increases the response to assisted reproductive technology.” (2)

Coenzyme Q10 is present in beef, pork, oily fish and nuts. However, to reach therapeutic levels of this nutrient, supplementation would be necessary. The recommended dose range of CoQ10 for male subfertility is 60 mg to 200 mg daily.

Written by Nadia Mason, BSc MBANT NTCC CNHC

References

1. The effect of coenzyme Q10 supplementation on partner pregnancy rate in infertile men with idiopathic oligoasthenoteratozoospermia: an open-label prospective study. MR Safarinejad. Int Urol Nephrol. Vol 44, no3 (2012) 689-700.

2. S. Kalra, B. Kalra, N. Agrawal: Nutraceutical Management Of Male Subfertility: An Update  . The Internet Journal of Family Practice. 2010 Volume 8 Number 2. DOI: 10.5580/1c4a

3. Image Courtesy of graur codrin

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Can CoQ10 be helpful for preventing post exercise pain?

On July 28 I wrote about coenzyme Q10 and the ability it has to potentially boost exercise performance.  Today I want to look into the antioxidant capabilities of this coenzyme and how these may relate to post exercise muscle pain.  A study published recently in the British Journal of Nutrition (1) found that CoQ10 supplementation reduced exercise-induced muscular injury in athletes.



When we exercise intensively we may actually cause damage to our muscle tissue.  This damage is believed to be causal in post-exercise muscle fatigue, pain and inflammation.  Intense exercise seems to be linked to the production of free radicals (unstable oxygen molecules).  These free radicals are quite destructive and can cause all kinds of problems within the body if they are not dealt with properly by natural bodily antioxidant systems.  These destructive free-radicals are believed to be behind some of the post-exercise issues in intense exercisers.



The body does produce its own antioxidants but also relies on vitamins, mineral and phytochemicals (bioactive plant chemical) from the diet, especially from colourful vegetables and fruits, for additional valuable supplies.



The production of free radicals within the muscles seems to increase in proportion to the intensity of exercise, as you push yurself harder during exercise more free radicals will be produced, and as mentioned above these free radicals may be responsible for some of the muscle damage, inflammation and pain experienced post-exercise(2).  Normally during the day, whilst we move around and at times of gentle and moderate exercise free radicals are generated at a low rate and are taken care of by our well developed antioxidant systems.  However, during intense exercise a greatly increased rate of free radical production may exceed the capacity of our natural antioxidant defence system.  Consequently, a substantial attack of free radicals on our cell membranes may lead to cell damage and could initiate inflammation and then pain or fatigue. 


 
Coenzyme Q10 is naturally produced by the body and was first isolated in 1957, it is essential for energy production in all bodily cells and also acts as an antioxidant in the body.  The study mentioned at the start of this post (1) found that individuals who were supplemented with CoQ10 had less evidence of free radical damage after intensive exercise than those who were not supplemented.



Exercisers who have a high intensity exercise regimen (exercise for over an hour 4 or more times a week) may want to look at the possibility of taking extra antioxidant supplements (to boost the natural antioxidant systems in the body), which could include a Co Q10 supplement.  It is also important to ensure the diet includes a minimum of 5 portions of vegetables and fruits.  These foods are naturally packed with antioxidant vitamins, minerals and flavonoids which are easily absorbed by the body and are also associated with reducing the risk of a number of diseases (including heart disease and cancer).



Coenzyme Q10 itself is found in many foods but is particularly concentrated in nuts and oils.  The body does produce this nutrient naturally and does not rely on external sources.  In order to produce CoQ10 we require various essential cofactors.  These include a variety of vitamins especially of the B group (Folic Acid, Vitamin B2, The Niacinamide form of Vitamin B3, Vitamin B5,Vitamin B6, Vitamin B12) and Vitamin C .  Hence a healthy diet rich in fruits, vegetables, wholegrain cereals and lean proteins will aid the natural production of this coenzyme and help to keep our circulating levels high.



(1)Michihiro K et al.  2008.  Reducing exercise-induced muscular injury in kendo athletes with supplementation of coenzyme Q10.  BJN.  100:903-909
(2) Sjodin B et al.  1990.  Biochemical mechanisms for oxygen free radical formation during exercise.  Sports Medicine.  10(4):236-254.


Written by Ani Kowal

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Coenzyme Q10 may help to boost your exercise performance

As I have mentioned before, I love to walk.  I can walk for hours!  Put me in a gym however and I tire quickly.  Personally I think this has more to do with boredom than my fitness!  A recent study seems to suggest that taking coenzyme Q10 supplements may increase the amount of time an individual can exercise before they become fatigued. 



Coenzyme Q10 is a type of fat-soluble coenzyme (the Q stands for Quinone), the most important Q coenzyme for humans.  A coenzyme is a compound that is necessary for the functioning of enzymes, protein substances produced in the body that act to accelerate biochemical reactions -enzymes are vital for all cellular processes in the body. 



Coenzyme Q10 is naturally produced by the body and was first isolated in 1957, it is essential for energy production in all bodily cells and is especially abundant in the heart – heart cells use a lot of energy in order to beat over 100,000 times a day!  Around the world it has become one of the most popular dietary supplements, with individuals reporting many health benefits such as increased energy and memory improvement.  Many trials (too many to reference here) have investigated this supplement and it seems to be beneficial for the prevention and treatment of many conditions from heart disease to blood pressure, cancer, circulatory conditions, gum disease, Alzheimer’s disease, Parkinson’s disease, immune related disorders and age related conditions.



As I mentioned at the start of this post the most recent research(1) on supplemental coenzyme Q10, also called CoQ10, suggests that it may enhance athletic performance and increase the time you can exercise before tiredness sets in.  The scientists involved in this study wanted to determine whether supplementation of CoQ10 could improve exercise performance in both trained and untrained individuals.  The study was small and involved 22 trained and 19 untrained individuals (male and female).  They received either a 100mg placebo or a CoQ10 supplement twice a day for 14 days.  Blood samples and muscle biopsies were taken.  On the first day the subjects were given a single dose of 200mg of the placebo or CoQ10.  One hour after being given the supplement the individuals were given a variety of endurance tests.  Additional blood samples and a second muscle biopsy were taken after completion of the tests.  After this first day the subjects were given 100mg of placebo or CoQ10 twice a day, once in the morning and once in the evening, for 14 days.  They then returned to the lab for more tests.



The levels of Coenzyme Q10 in the blood plasma were significantly increased following 2 weeks of the supplementation (compared to placebo group).  Following the one high dose of CoQ10 on day one muscle levels of CoQ10 were significantly higher and this was related to increased time to exhaustion on the treadmill (individuals could run for longer before tiring).  After two weeks of supplementation there was also a trend towards increased time to exhaustion.  Tests also revealed that the CoQ10 seemed to be acting as an antioxidant (individuals taking the CoQ10 had lower levels of oxidative stress).



The results make sense since Coenzyme Q10 is involved in the conversion of carbohydrates into energy.  This may explain why people who regularly take the supplement report an increase in their feelings of energy.  A previous small study(2) found that coenzyme Q10 supplementation at 150mg twice a day for two months increased blood levels of the nutrient and significantly increased the subjective perceived level of vigour in middle-aged men when compared to placebo.  A small study in cross country skiers(3) demonstrated the ability of coenzyme Q10 (90 mg per day) to increase all measures of physical performance.  In the study, 94% of skiers receiving coenzyme Q considered that their treatment has been beneficial in improving their performance.  In endurance runners(4) levels of CoQ10 were found to be lower than normal at rest (probably due to the increased need for energy production in such athletes) and further depleted after exercise training.  Supplemental CoQ10 improved the blood plasma levels in the runners and also seemed to help prevent the muscle damage that often occurs as a result of intensive exercise or endurance exercise(4).



If you are a regular gym-goer or generally training to improve fitness levels you may wish to try a coenzymeQ10 supplement to see if it benefits your training schedule.  50mg-100mg of the supplement twice per day is usually recommended.  As CoQ10 is fat soluble look for supplements that contain an oil base as these are more efficiently absorbed.



Coenzyme Q10 is found in many foods but is particularly concentrated in nuts and oils.  The body does produce this nutrient naturally and does not rely on external sources.  In order to produce CoQ10 we require various essential cofactors.  These include a variety of vitamins especially of the B group (Folic Acid, Vitamin B2, The Niacinamide form of Vitamin B3, Vitamin B5,Vitamin B6, Vitamin B12) and Vitamin C .  Hence a healthy diet rich in fruits, vegetables, wholegrain cereals and lean proteins will aid the natural production of this coenzyme and keep our circulating levels high. 



Just in case you are wondering, the research has not tempted me into the gym, I am more than happy with my walking (and the occasional hula-hooping)!



(1)Cooke M et al.  2008.  Effects of acute and 14-day coenzyme Q10 supplementation on exercise performance in both trained and untrained individuals. J Int Soc Sports Nutr.  4;5:8.
(2)Porter DA et al.  1995.  The effect of oral coenzyme Q10 on the exercise tolerance of middle-aged, untrained men.  Int J Sports Med.  16(7):421-427.
(3)Yikoski T et al.  1997.  The effect of coenzyme Q10 on exercise performance of cross-country skiers.  Molecular Aspects of Medicine (United Kingdom).  18(Supplement):S283-S290.
(4) Bargossi, A M et al.  1993.  Antioxidant effects of exogenous ubiquinone (Q10) in high level endurance runners.  Free Radicals and Antioxidants in Nutrition.  1993:63-74.


Written by Ani Kowal

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