NMN for Walking Speed, Muscle Function & Exercise Capacity: Trials
Educational summary — not medical advice. This is general walking-distance and aerobic-capacity evidence in non-elite populations, not elite-athlete performance data, and not a substitute for exercise or strength training. This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
The honest answer
The strongest, most-replicated pocket in the NMN evidence base — real, but narrower than "boosts performance." Five separate trials measured walking distance, gait speed, grip strength, or aerobic capacity, and four found a positive signal: dose-dependent 6-minute walk gains in middle-aged adults (Yi 2023), gait speed and grip strength in older men (Igarashi 2022, high dropout), dose-dependent aerobic capacity in recreational runners (Liao 2021), and secondary walking-speed improvements in older adults whose primary endpoints were null (Kim 2022, Morifuji 2024). None of this is elite-athlete or strength-training evidence.
Five trials, read carefully
This is the pocket of NMN evidence that replicates most consistently across independent research groups — which is exactly why it deserves the most careful reading, not the least. "Consistent signal in small trials" is not the same as "settled." Every trial here measured a walking, gait, or aerobic-capacity outcome in a healthy or generally healthy population; none tested elite athletes, and none tested strength or power outcomes.
| Study | Population & design | Dose & duration | Result |
|---|---|---|---|
| Yi 2023 PMID 36482258 | RCT, n=80, healthy adults 40-65y, multicenter (India) | 300/600/900 mg/day, 60 days | 6-min walk distance ↑ significantly in ALL dose groups at day 30 & 60 (p<0.01); 600-900 mg longest distances, 300 mg weakest. Co-authors affiliated with Abinopharm (NMN ingredient company). |
| Igarashi 2022 PMID 35927255 | RCT, n=42 randomized, only 20 completed, healthy older men | 250 mg/day, 6-12 weeks | Blood NAD+ ↑ significantly; nominally significant gait-speed and left-hand-grip improvements; no body-composition effect. Mitsubishi Corporation-funded. Half the cohort did not complete — high dropout, small completer-n. |
| Liao 2021 PMID 34238308 | RCT, n=48 recreationally-trained runners | 300/600/1200 mg/day, 6 weeks | Aerobic capacity (peak O2 uptake, ventilatory threshold) improved dose-dependently. No industry funding. Recreational, not elite, cohort; single-country. |
| Kim 2022 PMID 35215405 | RCT, n=108 randomized (105 completed), Japanese adults ≥65y | 250 mg/day (AM or PM), 12 weeks | Primary 5-times-sit-to-stand test: NO significant difference. PM-dosing group showed largest effect sizes for drowsiness and sleep-quality subscores (secondary). |
| Morifuji 2024 PMID 38789831 | RCT, n=60, older adults | 250 mg/day, 12 weeks | Primary stepping-test outcome: NO significant difference. Secondary: 4-meter walking time significantly shorter at 12wk vs placebo (which slowed); sleep quality improved. |
What "works" actually means here
Read precisely, the strongest version of this claim is: in several independent small trials, NMN supplementation was associated with improved walking distance, gait speed, or aerobic capacity, most consistently in middle-aged and older adults, at doses from 250 to 1200 mg/day over 6 to 12 weeks. It does not support "NMN builds muscle," "NMN increases strength," or any claim about competitive athletic performance — none of those outcomes were tested. Two of the five trials (Kim 2022, Morifuji 2024) found their primary outcome was null, with the walking-speed benefit only showing up as a secondary or subgroup result — that ordering matters, and skipping straight to the secondary finding overstates what the trial actually showed. And Igarashi 2022's positive result comes from a trial where half the randomized participants didn't finish, which shrinks the reliable sample considerably.
If you're taking it for walking speed or exercise capacity
If you want to try NMN for this specific reason with realistic expectations, 250 mg/day is the dose with the broadest single-dose trial support (see the dosage guide), while the dose-ranging data (Yi 2023, Liao 2021) suggests 600 mg and up may do more for walking distance and aerobic capacity specifically — though neither trial tested past 1200 mg, and going that high moves you closer to a safety ceiling that's only been tested for 4 weeks. None of these trials substitute for the intervention with by far the strongest evidence for walking speed and muscle function in older adults: structured exercise, particularly resistance training. If mobility decline, unexplained muscle loss, or a fall risk is the underlying concern, that's worth raising with a clinician rather than addressing with a supplement alone.
Frequently asked questions
Does NMN improve walking speed and muscle function?
NMN's strongest evidence pocket: 4 of 5 trials found positive signals on walking distance, gait speed, grip strength, or aerobic capacity at 250-1200 mg/day. Two had null primary endpoints with positive secondary findings.
Is NMN proven to boost athletic performance?
No. The strongest exercise trial (Liao 2021) studied recreational runners, not elite athletes. No trial tested strength, power, or competitive performance.
Can NMN replace exercise or strength training?
No trial tested or supports that. All trials measured walking/aerobic outcomes as endpoints, not as a comparison against or substitute for exercise.
Why did two trials have null primary endpoints?
Kim 2022 (sit-to-stand test) and Morifuji 2024 (stepping test) were both null on their primary outcome; walking-speed and sleep findings were secondary, hypothesis-generating results.
Related
- NMN: what it is & who it's for
- NMN dosage guide — the 250-1200 mg range in context
- Best NMN — ranked by purity/testing disclosure, then cost per mg
- NMN vs NR — and the full FDA story
Sources
- Yi L, et al. "The efficacy and safety of β-nicotinamide mononucleotide supplementation in healthy middle-aged adults." GeroScience. 2023. PMID: 36482258
- Igarashi M, et al. "Chronic nicotinamide mononucleotide supplementation elevates blood NAD+ in healthy middle-aged and older adults." NPJ Aging. 2022. PMID: 35927255
- Liao B, et al. "Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners." J Int Soc Sports Nutr. 2021. PMID: 34238308
- Kim M, et al. "Nicotinamide mononucleotide supplementation influences sleep quality in Japanese older adults." Nutrients. 2022. PMID: 35215405
- Morifuji M, et al. "Effects of a 12-week nicotinamide mononucleotide supplementation on physical function in older adults." GeroScience. 2024. PMID: 38789831