If you’ve been following longevity and performance research in recent years, you’ve likely encountered nicotinamide mononucleotide (NMN) as a hot topic. The promise is compelling: boost your cellular energy, support mitochondrial function, and potentially improve endurance. But what does the science actually say about how NMN impacts VO2 max and aerobic capacity in runners?
This guide breaks down the current evidence, explains what researchers have observed, and helps you make informed decisions about whether NMN supplements belong in your 2026 training toolkit.
Quick Answer: What We Know Today (2021–2025 Studies on NMN & VO2 Max)
Let’s cut straight to the point. Based on the most rigorous human data available—particularly the six week randomized trial conducted at Guangzhou Sport University and published in the Journal of the International Society of Sports Nutrition—NMN supplementation does not appear to increase maximum oxygen uptake (VO2 max) over short-term periods.
However, the picture isn’t entirely negative for endurance athletes. The same research showed statistically significant, dose dependent improvements in ventilatory threshold markers (VT1 and VT2) and oxygen uptake at these thresholds in the medium dosage group and high dosage group. This suggests NMN may enhance aerobic efficiency at submaximal intensities—the kind of effort you sustain during a half-marathon or tempo run—rather than boosting your absolute ceiling.
NMN is not a proven performance-enhancing drug. It’s being studied as a nicotinamide adenine dinucleotide (NAD+) precursor that may support cellular energy metabolism. The difference matters for both expectations and regulatory considerations.
At a Glance:
VO2 max: Little to no change in short-term trials (6 weeks)
Aerobic capacity/ventilatory threshold: Improved in 600mg and 1200mg daily doses
Mechanism: Likely improved skeletal muscle oxygen utilization, not cardiac function
Evidence base: Small, short trials; long-term effects remain unknown
None of this is medical advice. Runners should consult healthcare professionals before starting any supplement.
NMN, NAD+, and Energy Metabolism: Why Runners Care
To understand why researchers are studying NMN for exercise performance, you need to grasp its relationship with nicotinamide adenine dinucleotide NAD.
Nicotinamide mononucleotide NMN is a direct precursor to NAD+, a coenzyme found in every cell in your body. NAD+ plays a critical role in:
Glycolysis and the TCA cycle: Converting carbohydrates and fats into usable energy
Oxidative phosphorylation: The primary ATP production pathway during endurance exercise
Sirtuin activation: SIRT1 and related proteins linked to metabolic adaptation and mitochondrial biogenesis in animal studies
DNA repair: Supporting genome stability and enhancing anti-aging and healthspan by facilitating cellular repair mechanisms
Here’s the problem: NAD+ levels decline with aging and intense training. This decline can impair the oxidative capacity of your skeletal muscle—the very tissue responsible for sustaining pace during long runs.
NMN vs. Nicotinamide Riboside
Both NMN and nicotinamide riboside (NR) are NAD+ precursors. Multiple human trials from 2016–2024 confirm that both compounds raise circulating NAD+ levels. The 2021 amateur runners study used NMN at doses up to 1200 mg/day with no serious adverse events. NR supplementation studies have used doses up to 2000 mg/day in other populations.
Why This Matters for VO2 Max and Endurance:
Higher NAD+ availability may support more efficient ATP production during prolonged exercise. In theory, this could influence fatigue resistance and sustainable power output. However, current human data are limited and not conclusive for direct performance enhancement.
Key Human Study: NMN Supplementation in Amateur Runners (Guangzhou, 2021)
The most relevant research for runners comes from a four arm clinical trial conducted by Bagen Liao and colleagues, published in the Journal of the International Society of Sports Nutrition. The study included participants with varying backgrounds and fitness levels. It is important to note that factors related to each person, such as baseline fitness, fatigue levels, or individual characteristics, can significantly influence test outcomes and interpretations.
Study Design Details
This was a double blind study with placebo controlled methodology—the gold standard for supplement research. Here’s what the researchers set up:
| Group | Daily NMN Dose | Participants |
|---|---|---|
| Control group (Placebo) | 0 mg | 10 male participants, 2 female participants |
| Low dosage group | 300 mg | 10 male participants, 2 female participants |
| Medium dosage group | 600 mg | 10 male participants, 2 female participants |
| High dosage group | 1200 mg | 10 male participants, 2 female participants |
| Each group consisted of amateur runners aged approximately 20-40 years. In total, 48 participants completed the protocol, with two female participants per arm. |
Training Protocol
All four groups followed a structured exercise training program:
Frequency: 5–6 sessions per week
Duration: 40–60 minutes per training session
Modality: Combination of running and cycling
Intensity progression: Started at 90-100% of first ventilatory threshold (weeks 1-2), progressing to 90-120% VT1 (weeks 5-6)
Cardiopulmonary exercise testing was conducted on a cycle ergometer at baseline and after 6 weeks.
Primary Outcomes Measured
VO2 max (absolute and relative)
First ventilatory threshold (VT1) and second ventilatory threshold (VT2)
Oxygen uptake at thresholds
O2-pulse (a proxy for stroke volume)
Peak power output
Work rate relationships
Body composition markers
How NMN Affected VO2, VO2 Max, and Ventilatory Thresholds
Understanding the difference between VO2 max and ventilatory threshold is essential for interpreting these results.
VO2 max represents your ceiling—the maximum rate of oxygen consumption during exhaustive effort. It’s a measure of your integrated cardiovascular, respiratory, and muscular capacity.
Ventilatory threshold marks the point during exercise where breathing rate and lactate production increase disproportionately. This threshold closely predicts sustainable race pace for events from 10K to marathon.
Major Quantitative Findings
VO2 Max Results:
The researchers found no statistically significant change in VO2 max across any group over the 6-week period. Baseline values ranged from approximately 2.48-2.64 L/min, and post-intervention values showed similar ranges (2.34-2.56 L/min) with no significant differences between NMN groups and the placebo group.
This directly answers the question: Does NMN raise VO2 max? Based on this study, it does not—at least not within 6 weeks.
Ventilatory Threshold Results:
Here’s where things get interesting. The high dosage groups compared to control showed significant increases in:
Oxygen uptake at VT1
Percentage of VO2 max achieved at threshold (%VO2max)
Power output at VT1
Power output at VT2
The improvements were dose dependent, with 1200 mg showing superior gains over 600 mg in some markers. The low dosage group (300 mg) showed no significant benefits.
Cardiac Function Markers:
O2-pulse (an indicator of stroke volume) and the VO2/work rate relationship remained unchanged. This suggests NMN did not enhance cardiac pumping capacity or central cardiovascular function.
Interpretation for Runners
The researchers concluded that NMN likely enhanced oxygen utilization and metabolic efficiency in skeletal muscle rather than altering heart function. For runners, this translates to:
Better performance at submaximal intensities (tempo runs, steady-state efforts)
No improvement in all-out maximal capacity
Safety outcomes were reassuring: no serious adverse events and no ECG abnormalities over 6 weeks. However, this doesn’t guarantee long-term safety for all populations.
Mechanistic Insights: How Might NMN Influence Aerobic Capacity?
Most mechanistic data come from animal and cell studies, so these mechanisms remain somewhat hypothetical in humans.
Skeletal Muscle Mechanisms
Animal research from 2013–2020 has shown that NMN administration:
Increases NAD+ levels specifically in skeletal muscle tissue
Improves mitochondrial function and oxidative metabolism
Restores skeletal muscle capillary density toward more youthful levels in older mice
Increases capillary-to-myofiber ratio when combined with exercise
Link to Endurance Effects
These findings suggest potential pathways for improved functional capacity:
More capillaries per muscle fiber could enhance oxygen delivery during sustained efforts
Better mitochondrial function could improve fat and carbohydrate oxidation
Together, these changes might raise ventilatory threshold and delay fatigue
Human Evidence Outside Running
Other trials have reported improved walking speed in older adults, reduced fatigue, and improved muscle insulin sensitivity in prediabetic women following NMN supplementation. However, sample sizes are small (often ten male participants or fewer per group) and durations short (typically 60 days or less).
Critical Limitation: Translating mouse and in vitro results to human athletes remains uncertain. Doses, duration, and baseline health status differ substantially between laboratory conditions and real-world runners.
VO2 Max vs Aerobic Efficiency: What Runners Should Actually Focus On
Performance in races from 5K to marathon depends on multiple factors beyond raw VO2 max:
| Factor | What It Measures | Why It Matters |
|---|---|---|
| VO2 max | Maximum oxygen consumption | Absolute ceiling of aerobic capacity |
| Ventilatory threshold | Sustainable intensity before lactate accumulation | Predicts race pace for longer events |
| Running economy | Oxygen cost per kilometer | Efficiency at any given pace |
| Pacing strategy | Energy distribution over race distance | Practical performance optimization |
| In the 2021 NMN trial, ventilatory threshold and power at VT2 improved in the NMN groups—metrics arguably more relevant to race performance than marginal VO2 max changes alone. |
Practical Translation
An improved ventilatory threshold could allow a runner to hold a faster pace at the same perceived effort during a half-marathon or marathon. However, the study did not directly measure race times or long-term adaptations in competitive settings.
Important Caveat: NMN should not be seen as a substitute for structured training, adequate sleep, and proper nutrition. Even if NMN supports cellular metabolism, traditional training principles—progressive overload, periodization, recovery—remain the primary drivers of VO2 max gains and aerobic capacity improvements.
Evidence Gaps, Risks, and How to Think About NMN in 2026
Before drawing conclusions, consider the limitations of current research:
Main Evidence Gaps
Small sample sizes: Most trials involve tens of participants, not hundreds
Short durations: Typically 6–10 weeks; long-term efficacy and safety are unknown
Surrogate markers: Many studies track NAD+ levels or 6-minute walk distance rather than actual race performance
Limited population diversity: The Guangzhou study focused on young amateur runners; applicability to masters athletes or elite competitors is unclear
Methodological Concerns
Some critics have raised issues with:
Use of tools like Aging.AI 3.0 to estimate “biological age” in certain studies
Reliance on the 6-minute walk test (designed for frail or clinical populations) in healthy adult research
What Can Be Said Responsibly
| What We Know | What We Don’t Know |
|---|---|
| NMN raises blood NAD+ in a dose dependent fashion | Long-term effects on health or performance |
| Ventilatory threshold improved in medium/high doses | Whether effects persist beyond 6-10 weeks |
| No serious adverse events in short trials up to 1200 mg | Interactions with other supplements common among runners |
| Skeletal muscle appears to be primary target | Impact on actual race times |
Safety and Regulatory Notes
Regulatory status for NMN varies by country and may change over time. Check current rules in your region. Individuals with medical conditions, those taking medications, and those who are pregnant or breastfeeding should speak with a healthcare professional before considering NMN.
Practical Tips for Runners Considering NMN (Non-Medical, Informational)
This section is informational only—not a recommendation to start NMN. Consult a sports medicine professional or healthcare provider for personalized guidance.
Dose Ranges Used in Human Trials
Amateur runner study (Liao et al., 2021): 300–1200 mg/day
Aging/metabolic studies: 300–900 mg/day over approximately 60 days
Typical duration studied: 6–10 weeks
Training Integration Considerations
If researching NMN for personal use:
Pair any self-experiment with consistent training blocks to avoid confusing supplement effects with training variability
Track objective variables: pace at a given heart rate, time to exhaustion in standardized workouts, perceived exertion
Monitor recovery markers like heart rate variability
Foundational Strategies That Remain Primary
Before considering any supplement, ensure these basics are optimized:
Periodized endurance training: Base building, intensity blocks, appropriate tapers
Threshold-specific work: Interval and tempo sessions targeting both VO2 max and ventilatory threshold
Nutrition fundamentals: Adequate carbohydrate around key sessions, sufficient protein, proper hydration
Recovery practices: Sleep quality, stress management, strategic rest days
Evidence-Based Decision Making
Follow updates from reputable exercise physiology and sports nutrition journals
Maintain healthy skepticism toward marketing claims linking NMN to dramatic VO2 max or performance boosts
Remember that researchers at institutions like Guangzhou Sport University are conducting ongoing work—further information will emerge
Future Directions: What Research Runners Should Watch For
Several important questions remain unanswered as of 2026:
Key Unanswered Questions
Does NMN improve actual race performance (5K, 10K, half-marathon, marathon) in randomized controlled trials?
Are there meaningful long-term changes in VO2 max or running economy with NMN use beyond 6–10 weeks?
How do age, sex, training status, and baseline NAD+ levels influence individual responsiveness?
Desirable Features of Next-Generation Studies
Future trials should ideally include:
Larger sample sizes with balanced representation of male and female participants
Longer follow-up periods (6–12 months or more)
Standardized training programs across groups
Multiple performance endpoints: VO2 max, ventilatory threshold, time trials, actual race results, and recovery metrics
Related Research Areas
Keep an eye on:
NR supplementation studies in older adults and clinical populations
Metabolomics work exploring NAD+ dynamics during prolonged endurance exercise
Combination studies pairing NAD+ precursors with other interventions
Measured Perspective
NMN is a promising research tool for understanding how cellular metabolism interacts with exercise training. For now, its impact on VO2 max and real-world performance in healthy humans remains an open scientific question rather than a settled fact.
Conclusion: Where NMN Fits in the 2026 Runner’s Toolkit
Here’s what the current body of evidence tells us:
NMN is a NAD+ precursor that, in small short-term studies, improves ventilatory threshold but not VO2 max in amateur runners
The benefit appears to be aerobic efficiency at submaximal intensities, likely via skeletal muscle adaptations rather than cardiac function changes
Data are preliminary with substantial gaps regarding long-term use, safety in diverse populations, and real-world performance outcomes
Training quality, nutrition, and recovery remain the core drivers of both VO2 max and aerobic capacity—no supplement changes this fundamental truth
Significant increases in threshold-related markers occurred only at 600mg+ daily doses, showing clear dose dependent responses
NMN represents an evolving area of research—not a guaranteed performance enhancer. The science is interesting, the mechanisms are plausible, but the evidence isn’t yet strong enough to make definitive claims about race-day benefits.
Stay informed. Prioritize the fundamentals that have always worked. And if you’re considering NMN, do so with realistic expectations and professional guidance.
Train smart. Recover well. Stay curious about the science.
Further Reading
Explore more articles related to this topic:
- Is NMN Safe for Your Liver? Analyzing the Latest 2026 Hepatotoxicity Data
- Can NMN Replace Your Pre-Workout? A Look at Endurance and Muscle Recovery
- NMN and Urolithin A: The New Frontier of Mitochondrial Health in 2026
- Does NMN Interfere with Sleep? 5 Tips to Stop NMN-Induced Insomnia
- NMN and Coffee: Does Caffeine Synergize or Interfere with NAD+ Production?
