Glutamine for Exercise Recovery
Despite a plausible mechanism, glutamine has not been shown to meaningfully improve exercise recovery or athletic performance, and major regulators and sports-nutrition bodies regard it as ineffective for this purpose. The few positive trials are very small and mostly show changes in blood markers rather than real-world recovery.
Why this grade7-layer evidence engine
The strongest evidence points away from a benefit. A 2019 systematic review and meta-analysis pooling 25 trials (PMID 29784526) found no effect of glutamine on athletic performance, aerobic capacity, immune function, or body composition, with only a small drop in body weight. An earlier 6-week resistance-training RCT (PMID 11822473, n=31) likewise found no effect on strength, lean mass, or muscle-protein breakdown.
The positive signals are thin and fragile. Small crossover trials reported less soreness and faster strength recovery (PMID 25811544, n=16) and lower muscle-damage markers like creatine kinase (PMID 34204359, n=12). But samples are tiny, the soreness trial used a very high dose (~21 g/day, far above typical 5 g supplements), and a triathlete study (PMID 36685057, n=9) bundled glutamine with whey protein, so glutamine's own contribution cannot be isolated.
Authorities are consistently skeptical. The EU's EFSA rejected claims for muscle repair and post-exercise glycogen recovery, NIH's Office of Dietary Supplements states research does not support glutamine alone for performance, and the ISSN and IOC classify it as a non-effective supplement. Cleveland Clinic calls the evidence insufficient. Hence the weak, disputed C grade. (FDA approval of glutamine is only for sickle cell disease, not exercise.)
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.67
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (1 篇 > 0 negative)
- tier_strict_requirement_check — | B→C 因 scope.conflation_risk=true 且 L11 獨評較低 (B7-2 tier cap)
- detect_disputes — 偵測到 1 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status