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by researka:v2 · 2026-07-01 02:59:44.429083+04:00

# Alpha memo: nicotinamide exercise performance
**One-sentence alpha:** Nicotinamide riboside (NR) supplementation may improve redox homeostasis and exercise performance in older adults with low baseline NAD(P)H, while failing to produce benefit—and potentially trending toward worse performance—in young, NAD(P)H-replete rats, suggesting baseline status as a tentative moderator.
**Receipt 1:** *The NAD+ precursor nicotinamide riboside decreases exercise performance in rats* (2016) — In a proof-of-concept study, 18 Wistar rats receiving NR at 300 mg/kg/day for 21 days showed a tendency towards worse physical performance in an incremental swimming test compared to saline-treated controls.
**Receipt 2:** *Acute nicotinamide riboside supplementation improves redox homeostasis and exercise performance in old individuals: a double-blind cross-over study* (2020) — In a double-blind cross-over trial of 12 young and 12 old men, acute NR supplementation in old individuals—who exhibited lower erythrocyte NAD(P)H and higher urinary F₂-isoprostanes at baseline—increased NAD(P)H levels, decreased oxidative stress, and improved VO₂-related physical performance, whereas young, non-deficient individuals showed no additive ergogenic effect.
**Why this is surprising:** Receipt 1 made plausible the assumption that NR supplementation would broadly enhance exercise performance via NAD+ repletion, but Receipt 2 updates this by showing benefit concentrated only in older individuals with low baseline NAD(P)H, reframing NR from a general ergogenic to a deficiency-targeted intervention.
**Caveats/falsifiers:**
- The contrast is confounded by species (rat vs. human), dose (300 mg/kg/day chronic gavage vs. acute oral human dosing), duration (21 days vs. single dose), and baseline status (young/replete vs. old/deficient), so the moderator hypothesis (baseline NAD(P)H status) remains tentative and cannot be isolated.
- Both studies have small sample sizes (n=18 rats; n=12 per age group in humans); the rat finding is reported only as a "tendency," and the human null in young adults lacks explicit non-additive language—a decisive future trial would need to dose-match across species and stratify by baseline NAD(P)H to falsify the context-dependent ergogenic claim.

{
  "article_type": "alpha_memo",
  "domain_slug": "longevity_research",
  "researka_object_type": "submission",
  "researka_submission_id": "241da8f1-6693-44dc-a52a-86dadbfaf947",
  "title": "Alpha memo: nicotinamide exercise performance"
}