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Beta-hydroxybutyrate / Exogenous Ketones for Endurance

Verdict: Taiwan Regulatory Restriction

Across 4 PubMed studies, the evidence for Beta-hydroxybutyrate / Exogenous Ketones in Endurance grades Tier D — counter-evidence.

D 🔴 D Counter-Evidence Taiwan Regulatory Restriction

🔬Why this grade7-layer evidence engine

⚖️

Scoring transparency

All scores computed by a 7-layer evidence engine — fully auditable
Raw score 0.42
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
D · Taiwan Regulatory Restriction
Confidence
84%
Highly consistent evidence
Evidence level
E3
Single high-quality meta-analysis

How strongly each layer supports this effect

lower = less supportive
L1 ExamineGlobal benchmark
0.30
L11 AI re-checkIndependent read
0.30
L2 PubMedPrimary literature
0.45
L3 MechanismPlausibility
0.45
L5 Clinical bodiesAuthoritative stance
0.46
Against Mixed Supports
▸View the full decision path (audit trail)
  1. compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.422
  2. tier_from_score — 依分數區間映射至 tier letter
  3. apply_hec_rules — 高階證據未達主導 (0 positive vs 1 negative)，由 raw_score 決定
  4. tier_strict_requirement_check — Tier 條件達標，未降階
  5. detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
  6. decide_status — 依 tier + dispute 結果決定 status

📄PubMed studies (4)L2 · primary research & systematic reviews

Nutritional Ketosis Alters Fuel Preference and Thereby Endurance Performance in Athletes (Cox)
PMID: 27475046 2016 隨機對照試驗 n = 39
Finding: Ketone ester drink increased TT distance by ~2% (~400 m further) vs isocaloric carbohydrate control (p<0.05); shifted fuel use to ketones/fat.
Mixed funding Effect size: MD +411 m over 30 min TT (~2%)
View on PubMed
Effect of acute ingestion of beta-hydroxybutyrate salts on the response to graded exercise in trained cyclists (Evans/O'Malley)
PMID: 29338584 2017 RCT (double-blind) n = 10
Finding: BHB salts did not improve and tended to impair high-intensity exercise; time to exhaustion reduced (~2 min shorter, NS-trend); GI distress reported.
Academic Effect size: MD -7% TTE (NS)
View on PubMed
Utility of Ketone Supplementation to Enhance Physical Performance: A Systematic Review
PMID: 31586177 2021 統合分析 n = 184
Finding: Pooled effect of exogenous ketones on endurance performance was not significant (SMD 0.21, 95% CI -0.01 to 0.44, p=0.06); heterogeneity moderate; no clear ergogenic effect.
🟢 High quality Government Effect size: SMD 0.21 (95% CI -0.01 to 0.44)
View on PubMed
Ketone Monoester Followed by Carbohydrate Ingestion after Glycogen-Lowering Exercise Does Not Improve Subsequent Endurance Cycle Time Trial Performance
PMID: 38612966 2024 RCT (double-blind) n = 12
Finding: Ketone monoester did not improve TT performance vs CHO control (MD +14 s, NS); raised blood BHB to ~3-4 mM but no ergogenic effect.
Academic Effect size: MD +14 s on ~50 min TT (NS)
View on PubMed

🏛️Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …

L4a US FDA
Supportive
FDA has no questions source↗
L4b EU EFSA
Cautious
L5a NIH Office of Dietary Supplements
Cautious
L5c Cleveland Clinic
Neutral
Ketone supplements can help an athlete consuming carbohydrates last longer during an activity without having to re-fuel source↗
L5e Specialty Society (condition-mapped)
Cautious
Meta-analyses fail to show benefits to sports performance. source↗
✓PMID 100% verifiedevery citation checked via NCBI Entrez
🔬4 PubMed studiesindependently re-checked by multiple sub-agents
engine_version: v1.0 claim_id: CLM-COND-endurance-INT-beta-hydroxybutyrate-001 繁體中文版 →