NMN vs NR: Which NAD+ Booster Actually Helps Athletes?

I had a 38-year-old triathlete—let's call him Mark—come into my performance clinic last spring. He'd been hitting a wall in his training for months. His VO2 max was plateauing, his recovery between sessions was dragging, and his bloodwork showed elevated inflammatory markers that didn't match his clean diet. He was already taking half the supplements on the shelf. When he asked about adding an NAD+ booster, he looked at me and said, "Marcus, I've read everything. Do I go with NMN or NR?"

Look, I get this question at least twice a week now. The whole NAD+ space has exploded with claims about reversing aging, boosting energy, and enhancing athletic longevity. Your social media feed is probably full of influencers pushing one or the other. But here's the thing—your body doesn't read marketing copy. It responds to biochemistry, bioavailability, and what actually shows up in human trials.

I've worked with athletes from Olympic hopefuls to weekend warriors for over a decade. I bought into the protein timing myth for years before the data caught up. So I'm careful about jumping on supplement trends. With NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside), we've got decent human data now—but it's messy, and the practical implications for athletes are what matter.

Quick Facts: NMN vs NR for Athletes

What the Research Actually Shows

Let's cut through the hype. NAD+ (nicotinamide adenine dinucleotide) is a coenzyme in every cell that declines with age and stress. For athletes, that matters because NAD+ is crucial for mitochondrial function—your cellular power plants. More NAD+ should mean better energy production, better recovery, and potentially delayed fatigue. The question is which precursor gets you there reliably.

Nicotinamide Riboside (NR) – The Human Data Leader

NR has the most robust human exercise studies. A 2022 randomized controlled trial published in Cell Reports (PMID: 35081345) really caught my attention. Researchers gave 500 mg twice daily of NR to 40 recreationally active adults (n=40) over 6 weeks. The NR group showed a 17% increase in NAD+ levels in skeletal muscle compared to placebo (p=0.008). More importantly for athletes, they had improved mitochondrial respiration—meaning their muscle mitochondria were producing energy more efficiently.

But here's where it gets practical. Another study—this one from 2021 in Nature Communications (doi: 10.1038/s41467-021-22112-4)—looked at older adults (ages 55-79) taking 1,000 mg NR daily. After 6 weeks, they saw significant reductions in inflammatory cytokines (IL-6 decreased by 40%, 95% CI: 32-48%). For athletes dealing with training-induced inflammation, that's potentially huge.

I had a 45-year-old cyclist client—former collegiate rider—who added NR (300 mg daily of Jarrow Formulas' NR) during his base training phase. After 8 weeks, his perceived recovery scores improved by 22%, and his post-ride muscle soreness (measured via VAS scale) dropped noticeably. Was it all the NR? No—but it was part of a targeted protocol.

Nicotinamide Mononucleotide (NMN) – The Promising Contender

NMN gets more buzz lately, partly because of high-profile proponents. The biochemistry makes sense—NMN is one step closer to NAD+ in the conversion pathway. But—and this is a big but—human data is thinner.

A 2023 study in GeroScience (PMID: 36738476) gave 250 mg NMN daily to 80 middle-aged adults (n=80) for 12 weeks. They reported improved insulin sensitivity and lipid profiles, but no significant changes in exercise performance metrics. That's important context.

Where NMN shows potential is in older or sedentary populations. A 2022 Japanese trial (doi: 10.18632/aging.204460) with 65-80 year olds found that 250 mg NMN daily improved walking speed and grip strength over 12 weeks. But for athletes in their 30s-50s? The data just isn't as compelling yet.

Honestly, the NMN research frustrates me. The animal studies are fantastic—mice running farther, living longer. But human athletes aren't oversized mice. We need sport-specific outcomes: time to exhaustion, power output, recovery markers.

Dosing & Practical Recommendations

Here's where most people mess up. They underdose or take it inconsistently.

For NR:

• Effective dose: 300-500 mg daily for maintenance, 500-1,000 mg daily during intense training blocks
• Best form: NR chloride (the form used in most studies)
• Timing: Split dose—morning and early afternoon. Don't take late—it can interfere with sleep in some people.
• What I use: With my athletes, I typically start with 300 mg daily of Thorne's ResveraCel (which combines NR with other mitochondrial supporters) and adjust based on training load.

For NMN:

• Effective dose: 250-500 mg daily based on current studies
• Absorption note: Some evidence suggests sublingual or liposomal forms might bypass digestion issues
• Brand consideration: If going NMN, I'd look at ProHealth Longevity's NMN or Life Extension's NAD+ Cell Regenerator—both have third-party testing.

Point being—you need consistency. Taking 100 mg every other day won't move the needle. These aren't stimulants; they're nutrient precursors that need to accumulate.

One more thing—cost. NR typically runs $40-60 per month at effective doses. NMN can be $50-80. If that's prohibitive, focusing on foundational nutrition (adequate protein, magnesium, B vitamins) gives you more bang for your buck.

Who Should Avoid or Be Cautious

Neither NMN nor NR is risk-free, despite what supplement companies imply.

Hold off if:

• You're pregnant or breastfeeding (no safety data)
• You have active cancer or are undergoing treatment (theoretical risk of feeding tumor growth—though unproven)
• You have severe kidney or liver disease (clearance concerns)
• You're on chemotherapy drugs (potential interactions)

Start low if:

• You're sensitive to supplements (begin with 100 mg NR or NMN)
• You have autoimmune conditions (monitor inflammatory responses)
• You're taking multiple medications (check with your doctor—especially if on blood pressure or diabetes meds)

I had a 50-year-old tennis player develop mild headaches when starting NR at 500 mg. We dropped to 150 mg for a week, then ramped up slowly. Her system adjusted. Your body will tell you—listen to it.

FAQs

1. Can I take both NMN and NR together?
Some products combine them, but we lack data on synergistic effects. I prefer picking one and assessing response over 8-12 weeks. Stacking them mostly just increases cost.

2. How long until I notice effects?
Most studies show NAD+ level changes in 2-4 weeks, but functional benefits (recovery, endurance) take 6-12 weeks. This isn't a pre-workout—it's a cellular support supplement.

3. Should younger athletes (under 30) take NAD+ boosters?
Probably not worth it unless you're under extreme training stress. Your NAD+ levels are naturally higher. Focus on sleep, nutrition, and training periodization first.

4. What about NMN banned by the FDA?
That was specific to NMN being marketed as a drug before being sold as a supplement. It's still available, but regulatory status is messy. NR has generally recognized as safe (GRAS) status.

Bottom Line

Back to Mark, my triathlete. We went with NR at 300 mg daily, along with some adjustments to his training periodization. Three months later, his inflammatory markers dropped into optimal range, and he set a half-Ironman PR. Was it all the NR? No—but it was part of a targeted approach based on what the human data actually shows.

Look, the research will evolve. Five years from now, I might be recommending something entirely different. But right now, for athletes asking about NAD+ boosters, the evidence points toward NR as the more reliable choice. Just don't expect miracles—expect subtle, cellular-level support that shows up in your recovery metrics over time.