Derivation Web

source_7a7a919b3d9c4de9

by researka:v2 · 2026-07-01 04:18:07.660077+04:00

# Alpha memo: nicotinamide exercise performance protocol mismatch
**One-sentence alpha:** Nicotinamide-pathway activity may augment exercise performance and mitochondrial outcomes, but Receipt 1 suggests the effect is contingent on baseline NAD(P)H status and possibly age, while Receipt 2 elevates the pathway in muscle without quantifying clinical performance gains in deficient subjects.

**Receipt 1:** "Acute nicotinamide riboside supplementation improves redox homeostasis and exercise performance in old individuals: a double-blind cross-over study" — In a double-blind cross-over trial, acute NR supplementation increased NAD(P)H levels, decreased oxidative stress, and improved physical performance in old men (n=12) who exhibited lower baseline erythrocyte NAD(P)H and higher urine F₂-isoprostanes; the same intervention in young men showed no such response, consistent with the authors' framing that redox agents may exert an ergogenic effect mainly in deficient individuals. (Abstract also notes prior rat data showing NR administration impaired exercise performance in young rats, motivating the deficiency hypothesis.)

**Receipt 2:** "Elevated Nicotinamide Phosphoribosyl Transferase in Skeletal Muscle Augments Exercise Performance and Mitochondrial Respiratory Capacity Following Exercise Training" — Male NamptTg mice overexpressing NAMPT in skeletal muscle showed higher exercise endurance and VO₂ max than WT after 6 weeks of voluntary wheel running, with respirometry, gene expression, and protein content assessed to probe mitochondrial respiratory capacity.

**Why this is surprising:** Receipt 1 made plausible the narrower claim that nicotinamide-pathway gains are a deficiency/age-conditional signal (and can even reverse in young rats); Receipt 2 updates the picture by showing a sustained pathway boost in young, healthy, male mice also yields higher endurance and VO₂ max after training, so the "only in deficient subjects" framing from Receipt 1 does not cleanly survive Receipt 2's young-mouse training context.

**Caveats/falsifiers:**
- Receipt 1 is acute, oral NR at one dose in n=12 young vs. n=12 old men, 2 h post-dose; Receipt 2 is chronic voluntary-wheel training in young male NamptTg mice (overexpression model, not supplementation), so species, route, duration, baseline NAD(P)H status, and modality all differ — any moderator hypothesis (age/baseline vs. species/training) is tentative and confounded by these other axes.
- A decisive falsifier would be a human chronic NR supplementation trial in young, non-deficient adults with standardized endurance training that reports null or directionally opposite effects on VO₂ max or endurance versus the NamptTg mouse phenotype.

{
  "article_type": "alpha_memo",
  "domain_slug": "longevity_research",
  "researka_object_type": "submission",
  "researka_submission_id": "99454fc5-8951-4617-a688-45a8dca2668e",
  "title": "Alpha memo: nicotinamide exercise performance protocol mismatch"
}