A six-week study of 54 healthy men found that ubiquinol supplementation increased CoQ10 blood levels and improved cellular energy efficiency, but did not improve exercise performance or endurance capacity. According to Gram Research analysis, while ubiquinol is better absorbed than regular CoQ10, this absorption advantage doesn’t translate to better athletic results in healthy, active people.
Researchers tested whether a special form of CoQ10 called ubiquinol could help healthy, active men exercise longer and harder. Fifty-four men took either 300 mg of ubiquinol or a placebo pill every day for six weeks. While the supplement did increase CoQ10 levels in the blood and improved how efficiently cells use oxygen, it didn’t actually help people exercise longer or perform better during intense cycling tests. The findings suggest that even though ubiquinol gets into the body better than regular CoQ10, it may not translate to real-world exercise benefits for already-healthy, active people.
Key Statistics
A 2026 randomized controlled trial of 54 healthy males found that six weeks of 300 mg daily ubiquinol supplementation increased plasma CoQ10 levels but failed to improve exercise time to exhaustion or oxygen uptake during intense cycling tests.
Ubiquinol supplementation improved oxidative phosphorylation coupling efficiency in muscle cells by enhancing cellular energy production efficiency, yet this microscopic improvement did not translate to measurable gains in exercise performance in healthy, recreationally active men.
In a double-blind study published in the European Journal of Applied Physiology, ubiquinol showed no effect on mitochondrial leak proteins (ANT1+2 and UCP-3) or oxygen uptake kinetics during severe-intensity exercise compared to placebo.
The Quick Take
- What they studied: Whether taking ubiquinol (a form of CoQ10) for six weeks could improve how well muscles use oxygen and help people exercise longer and harder
- Who participated: 54 healthy, recreationally active men (people who exercise regularly but aren’t professional athletes) were randomly assigned to take either ubiquinol or a placebo
- Key finding: Ubiquinol increased CoQ10 levels in the blood and improved cellular energy efficiency, but didn’t help people exercise longer or improve their oxygen use during intense exercise
- What it means for you: If you’re already healthy and active, taking ubiquinol supplements probably won’t make you a better athlete, even though it does get into your body. People with specific health conditions might see different results, but this study only looked at healthy people
The Research Details
This was a randomized controlled trial, which is considered one of the strongest types of research. Fifty-four healthy men were randomly split into two groups: one group took 300 mg of ubiquinol (the reduced form of CoQ10) daily, while the other group took a placebo (fake pill) for six weeks. Neither the researchers nor the participants knew who was taking the real supplement—this is called “double-blind” and helps prevent bias.
Before and after the six weeks, researchers measured how well the men’s muscle cells could use oxygen by taking tiny muscle samples. They also measured specific proteins in the cells that affect energy production. Finally, the men completed an intense cycling test where they pedaled as hard as they could until they couldn’t continue, and researchers measured how long they lasted and how much oxygen their bodies used.
This design is strong because the random assignment and blinding reduce the chance that results are due to luck or expectations rather than the actual supplement.
This research matters because previous studies using the regular form of CoQ10 (ubiquinone) showed no benefits for exercise, so scientists wanted to test the newer form (ubiquinol) that the body absorbs better. If ubiquinol worked, it could help athletes and active people improve their performance. Understanding how supplements affect the tiny energy factories in our cells (mitochondria) helps us know which supplements are actually worth taking.
This study has good quality because it used a randomized, double-blind design with a control group, which is the gold standard for supplement research. The sample size of 54 people is reasonable for this type of study. The researchers measured actual cellular changes, not just what people reported. However, all participants were already healthy and active, so results might be different for people who are less fit or have health conditions. The study was published in a respected scientific journal (European Journal of Applied Physiology), which means it passed peer review by other experts.
What the Results Show
The ubiquinol supplement did exactly what it was supposed to do in one way: it significantly increased CoQ10 levels in participants’ blood compared to the placebo group. The supplement also improved something called “oxidative phosphorylation coupling efficiency,” which is a fancy way of saying the cells’ energy-making machinery worked more efficiently at converting fuel into usable energy.
However, these improvements didn’t translate into better exercise performance. When the men completed the intense cycling test, there were no differences between the ubiquinol group and the placebo group in how long they could exercise (called “time to limit of tolerance”) or how much oxygen their bodies used during the test. The supplement also didn’t change specific proteins in the cells that affect energy production and heat generation.
This disconnect is important: even though ubiquinol improved cellular efficiency on a microscopic level, it didn’t help people actually exercise better in real-world conditions.
The study measured several other variables related to how muscles use oxygen during exercise, including oxygen uptake kinetics (how quickly the body ramps up oxygen use when exercise starts) and end-exercise oxygen consumption. None of these measures showed differences between the ubiquinol and placebo groups. The supplement was well-tolerated with no reported side effects, suggesting it’s safe to take at this dose.
This finding aligns with previous research on regular CoQ10 (ubiquinone), which also showed no benefits for exercise performance in healthy people. The key difference is that ubiquinol has better bioavailability, meaning the body absorbs it better and gets more of it into the bloodstream. This study confirms that better absorption doesn’t necessarily mean better results. Some older studies suggested CoQ10 might help people with heart disease or age-related decline, but this study focused on healthy, active young men.
The biggest limitation is that all participants were already healthy and recreationally active, so results might be different for people who are less fit, older, or have health conditions like heart disease or diabetes. The study only lasted six weeks, so we don’t know if longer supplementation might eventually show benefits. The study measured cellular changes in muscle biopsies, which is good, but these don’t always predict real-world performance. Finally, the sample size of 54 is moderate—larger studies might detect smaller effects that this study missed.
The Bottom Line
For healthy, active people: ubiquinol supplementation is probably not worth the cost if your goal is to improve exercise performance. The evidence is strong (from a well-designed study) that it won’t help. For people with specific health conditions like heart disease, mitochondrial disorders, or age-related muscle loss: talk to your doctor, as this study doesn’t apply to you. If you’re already taking CoQ10 for other reasons, ubiquinol is better absorbed than regular CoQ10, but don’t expect exercise benefits.
Athletes and active people wondering if supplements can boost performance should know this won’t help. People with heart disease, age-related decline, or mitochondrial conditions might want to discuss CoQ10 with their doctor (though this study didn’t test those populations). People selling ubiquinol supplements for athletic performance should note this research doesn’t support those claims.
This study ran for six weeks, which is a reasonable time for CoQ10 to build up in the body and show effects. If ubiquinol was going to help exercise performance, six weeks would likely be enough time to see it. Don’t expect benefits from taking this supplement for exercise, whether you take it for six weeks or longer.
Frequently Asked Questions
Does CoQ10 help you exercise longer and harder?
For healthy, active people, research shows CoQ10 supplementation doesn’t improve exercise performance or endurance. A 2026 study of 54 men found ubiquinol increased blood CoQ10 levels but didn’t help them exercise longer during intense cycling tests.
Is ubiquinol better than regular CoQ10 for athletes?
Ubiquinol is absorbed better by the body than regular CoQ10, but a 2026 trial found this advantage doesn’t translate to better athletic performance in healthy people. Both forms showed no exercise benefits in research studies.
How long does it take for CoQ10 supplements to work?
Six weeks is typically enough time for CoQ10 to build up in your body and show effects. This 2026 study ran for six weeks and found cellular changes but no performance improvements, suggesting if it were going to help, you’d see it within that timeframe.
Can CoQ10 improve mitochondrial function?
Ubiquinol can improve how efficiently mitochondria produce energy at the cellular level, according to a 2026 study. However, this microscopic improvement didn’t translate to better exercise performance, suggesting cellular efficiency gains don’t always mean real-world benefits.
Who should take ubiquinol supplements?
This study only tested healthy, active people and found no exercise benefits. People with heart disease, age-related muscle loss, or mitochondrial disorders might benefit differently, but should consult their doctor rather than relying on athletic performance research.
Want to Apply This Research?
- If users are considering ubiquinol supplementation, track weekly exercise performance metrics (cycling time to exhaustion, max heart rate, perceived exertion) and compare before/after six weeks to see if the supplement helps them personally, even though population research suggests it won’t
- Users interested in optimizing mitochondrial function should focus on proven methods: consistent aerobic exercise, strength training, and adequate sleep—all of which improve mitochondrial health more reliably than supplements
- Track actual exercise performance (time, distance, intensity) rather than relying on how you feel, since cellular improvements don’t always translate to noticeable performance gains
This research applies specifically to healthy, recreationally active men and should not be interpreted as medical advice for people with heart disease, mitochondrial disorders, or other health conditions. CoQ10 supplementation may have different effects in these populations. Always consult with a healthcare provider before starting any supplement regimen, especially if you take medications or have existing health conditions. This study measured performance in laboratory conditions; individual results may vary. The findings do not support using ubiquinol as an ergogenic aid for healthy athletes.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.