Mitoquinol and Endurance Training Adaptations
Written by Tyla Cornish (BNatMed), Naturopath. Reviewed by Dr. Siobhan Mitchell (PhD), Neuroscience.
Reactive oxygen species (ROS) are central to exercise adaptation, functioning as signalling molecules that promote mitochondrial and vascular changes in response to training. A key concern with antioxidant supplementation has been whether suppressing ROS — even partially — might blunt these adaptive signals and reduce the gains achieved through endurance training. This study investigated whether a mitochondria-targeted antioxidant influences training-induced adaptations in healthy individuals, helping to clarify whether targeted approaches carry the same theoretical risk as general antioxidants.
Research Summary
Evidence type: Randomised, double-blind, placebo-controlled trial
Claim strength: Causal, negative
Population: 20 healthy young men
Intervention: Mitoquinol 10 mg/day vs placebo + endurance training (3 week period)
Primary outcomes: VO₂max, mitochondrial capacity, circulating angiogenic cells
Observed outcome: Exercise improved VO₂max and mitochondrial capacity; Mitoquinol had no effect on these adaptations
Causality: Not supported for modifying training adaptations
Primary source: Journal of Physiology
What you’ll learn
Whether mitochondria‑targeted antioxidants interfere with endurance training adaptations
How reactive oxygen species (ROS) function as both signalling molecules and stressors in exercise
Why MitoQ does not blunt or enhance physiological adaptations in healthy individuals
The importance of population context when evaluating antioxidant effects on training outcomes
What the Study Observed
Following three weeks of endurance training with either Mitoquinol or placebo, participants in both groups showed comparable improvements in VO₂max and mitochondrial capacity. Mitoquinol neither enhanced nor impaired these training-induced adaptations, indicating that mitochondria-specific antioxidant supplementation at 10 mg daily does not interfere with — or augment — exercise-driven physiological improvements in healthy young men.
What Are the Implications for Training?
This is a practically important null finding, and it can be read in two directions simultaneously. On one hand, it provides reassurance that Mitoquinol does not blunt training adaptations — a concern prompted by evidence that general antioxidant supplementation can interfere with ROS-dependent exercise signalling. On the other hand, it confirms that at this dose, in this population, Mitoquinol confers no additional adaptive benefit beyond what training alone achieves.
The population enrolled here is the most likely explanation for both findings. Healthy young men undergoing endurance training have highly responsive mitochondrial and vascular systems, robust endogenous antioxidant defences, and training-induced ROS signals that are functioning normally as drivers of adaptation. There is no excess oxidative burden for Mitoquinol to correct, and no impaired signalling that it needs to restore. The molecule appears to sit in the background without disrupting the training response — neither helping nor harming a system that is already working well.
The low dose of 10 mg is also worth noting. This is the lowest dose used in any of the published Mitoquinol trials, and it is possible that mitochondrial accumulation was insufficient to produce detectable effects on any endpoint in a healthy exercising population.
Critical Considerations for Future Research
To determine whether Mitoquinol can genuinely augment training adaptations, future studies should look beyond healthy young adults. Populations with elevated resting oxidative stress — older athletes, individuals with metabolic syndrome, or those in very high training loads where mitochondrial ROS production is chronically elevated — represent more appropriate targets. A higher dose (20 mg or above) should be used to ensure adequate mitochondrial accumulation. Longer training periods of eight to twelve weeks would also provide more time for any molecular effects to manifest in functional outcomes, and the inclusion of submaximal performance metrics alongside VO₂max would increase sensitivity to modest effects.
Read the full paper:Mitochondria-specific antioxidant supplementation does not influence endurance exercise training adaptations
DOI: 10.1113/JP272491
