Exercise ageing research: mitoquinol (MitoQ) and leg power in older adults

Written by Georgia Truman (MSc), Molecular and Cellular Biology. Reviewed by Dr. Siobhan Mitchell (PhD), Neuroscience.

Ageing is associated with progressive declines in motor function, including reductions in strength, balance, endurance, and power. Among these, declines in muscular power occur earlier and are more strongly associated with loss of physical function, mobility limitations, and increased risk of disability. Mitochondrial dysfunction and increased production of reactive oxygen species (ROS) have been proposed as contributing factors to these age-related changes.

This study investigated whether a mitochondria-targeted antioxidant (Mitoquinol, also known as MitoQ) could improve motor function, with a specific focus on leg-extension power, in healthy late middle-aged and older adults.

Research Summary

• Evidence type: Randomised, placebo-controlled, crossover trial

• Claim strength: Causal (physiological endpoint), positive (specific outcome)

• Population: 18 healthy late middle-aged and older adults (60–79 years)

• Intervention: Mitoquinol 20 mg/day vs placebo (6 weeks)

• Primary outcomes: Leg-extension power; motor function (NIH toolbox); VO₂max

• Observed outcome: Increased leg-extension power (~11% vs placebo), no change in strength, balance, endurance, or VO₂max

• Causality: Supported for leg power improvement

• Source: The Faseb Journal

What you’ll learn

• Whether mitochondrial-targeted antioxidants can improve muscle power in ageing

• Why declines in power are critical determinants of mobility and functional capacity

• How improvements in specific motor domains may occur independently of overall fitness

• The relationship between baseline function and responsiveness to intervention

Why mitochondrial function was targeted

Age-related declines in physical function have been linked in part to increased mitochondrial oxidative stress. Excess production of reactive oxygen species may impair muscle function and reduce the efficiency of energy production, contributing to declines in power and mobility. Targeting mitochondrial ROS offers a mechanistically distinct approach to supporting physical function beyond traditional exercise or strength-based interventions.

What the study observed

Participants completed 6 weeks of supplementation with Mitoquinol or placebo in a crossover design, with motor function assessed using both targeted measures and broader functional tests.

Mitoquinol supplementation resulted in a significant increase in leg-extension power, with average output approximately 11% higher compared to placebo conditions. Importantly, the improvement was more pronounced in individuals with lower baseline power, suggesting a differential response based on initial functional status.

In contrast, no improvements were observed in other domains of physical function, including leg strength, balance, endurance, or aerobic capacity. These findings indicate that the effects of Mitoquinol were specific to muscular power rather than generalised across all aspects of motor performance.

What are the implications for ageing and physical function?

This study highlights a highly targeted effect of mitochondrial antioxidant supplementation: improvement in muscular power without broader changes in overall fitness or functional capacity. Given that declines in power are among the earliest and most functionally relevant changes with ageing, this finding is clinically meaningful despite the absence of broader performance effects.

The selective improvement in power also reinforces a recurring theme across the MitoQ Mitoquinol literature — that mitochondrial-targeted interventions may influence specific physiological domains rather than producing uniform, whole-system effects. In this case, leg-extension power, which is closely linked to mobility, fall risk, and independence, appears more responsive than strength or aerobic capacity.

Taken together, these findings suggest that mitochondrial-targeted supplementation may be most relevant for addressing early functional decline, particularly in individuals with reduced baseline capacity. The greater response observed in lower-functioning participants supports the idea that interventions targeting mitochondrial dysfunction may be most effective where oxidative burden is elevated and functional reserve is already compromised. In practical terms, this positions mitochondrial support as a potential adjunct strategy for maintaining mobility and delaying disability in ageing populations, while also reinforcing that improvements may be domain-specific rather than global.

What should practitioners know about dosing and use?

Participants took 20 mg daily for 6 weeks. The intervention improved leg power without affecting other measures of physical performance, suggesting that mitochondrial-targeted supplementation may influence specific aspects of motor function rather than overall fitness. These findings highlight the importance of selecting appropriate outcome measures when assessing functional benefits in ageing populations.

Read the full paper: MitoQ supplementation improves leg-extension power in healthy late middle-aged and older adults

DOI: 10.1096/fasebj.31.1_supplement.lb852