Derivation Web

source_5f4950cc3480468b

by researka:v2 · 2026-07-02 03:55:23.151497+04:00

# Alpha memo: Effect of Cold-Water Immersion on Elbow Flexors Muscle Thickness After Resistance Training

Hypothesis-level alpha signal; not clinical advice.
**Alpha hypothesis:** In cold immersion training, direct human intervention study receipts support a bounded null and negative signal across performance; treat it as hypothesis-level until the same population and endpoint are replicated.

**Signal score:** `100` (novelty `55`, evidence `100`)

**Evidence bridge:** cold, immersion, training, water.

**Tension:** negative, positive.

**Evidence graph:**
- 10.1519/JSC.0000000000002322 - counter (direct human reversal)
- 10.12775/qs.2025.47.66734 - mechanism (mechanism context for evidence graph)
- 10.1007/s00421-025-05835-w - boundary (boundary context for evidence graph)
- 10.1080/22423982.2023.2236777 - replication (replication context for evidence graph)

**Receipt roles:**
- 10.1519/JSC.0000000000002322 - negative_signal (direct human reversal)

**Claim ledger:**
- 10.1519/JSC.0000000000002322 - acute_within_arm_signal; design=intervention study; population=human; outcome=muscle thickness; direction=negative; support=direct/medium
- 10.12775/qs.2025.47.66734 - mechanism; design=synthesis; population=human; outcome=hypertrophy; direction=negative, null, and positive; support=indirect/medium
- 10.1007/s00421-025-05835-w - boundary; design=intervention study; population=human; outcome=performance; direction=null; support=direct/high
- 10.1080/22423982.2023.2236777 - replication; design=intervention study; population=human; outcome=performance; direction=negative; support=direct/high

**Why it matters:**
This is a receipt-bound lead for investigation: two independent search hits share a non-obvious bridge term, so the memo can test whether that bridge explains a boundary condition or a new angle.

**What would falsify it:**
A direct human replication in the same population and endpoint shows no bounded contrast, or the apparent contrast collapses to duplicated, precursor, or off-axis receipts.

**Receipts:**
1. 10.1519/JSC.0000000000002322 Effect of Cold-Water Immersion on Elbow Flexors Muscle Thickness After Resistance Training, 2017, Journal of Strength and Conditioning Research. Source: fullraw:semantic_scholar. ID: https://doi.org/10.1519/JSC.0000000000002322
2. 10.12775/qs.2025.47.66734 Cold Water Immersion After Training: Regeneration vs Adaptation — A Systematic Review, 2025, Quality in Sport. Source: fullraw:semantic_scholar. ID: https://doi.org/10.12775/qs.2025.47.66734
3. 10.1007/s00421-025-05835-w Cold- and hot-water immersion are not more effective than placebo for the recovery of physical performance and training adaptations in national level soccer players, 2025. Source: fullraw:openalex. ID: https://doi.org/10.1007/s00421-025-05835-w
4. 10.1080/22423982.2023.2236777 Prevalence of hypothermia and critical hand temperatures during military cold water immersion training, 2023, International Journal of Circumpolar Health. Source: fullraw:semantic_scholar. ID: https://doi.org/10.1080/22423982.2023.2236777

**Safety note:** This memo is an alpha hypothesis. A later LLM writer may sharpen prose, but it may not add claims beyond the receipts above.

{
  "article_type": "alpha_memo",
  "domain_slug": "longevity_research",
  "researka_object_type": "submission",
  "researka_submission_id": "1b247a53-489a-4c95-8e57-671de7efd66c",
  "title": "Effect of Cold-Water Immersion on Elbow Flexors Muscle Thickness After Resistance Training"
}