Glutamine and the effects of exhaustive exercise upon the immune response.
Level 5 - mechanism / opinion, no new human data
Narrative review of previous studies and mechanistic rationale without systematic review methodology.
PubMed 9839078 · doi:10.1139/cjpp-76-5-524
What was done
The authors reviewed the physiological rationale and findings from a series of studies investigating oral glutamine supplementation versus placebo in sedentary individuals, marathon runners, and ultramarathon runners before and after prolonged, exhaustive exercise. Outcomes examined in those studies included the incidence of post-exercise infections (notably upper respiratory tract infections) and markers of the acute-phase response.
What was found
The abstract reports no numerical values, effect sizes, or statistical significance levels. It reports qualitatively that prolonged exhaustive exercise reduces plasma glutamine concentrations and that oral glutamine administration appeared to reduce the incidence of post-marathon infections reported by runners compared with placebo.
Why it matters
It outlines the hypothesis linking exercise-induced plasma glutamine depletion to transient immunosuppression, suggesting oral glutamine as a potential nutritional countermeasure for endurance athletes susceptible to upper respiratory infections.
Limits
As a narrative review, the abstract provides no specific sample sizes, trial quality assessments, or quantitative data. Infection rates in the referenced studies appear to rely on self-reported symptoms, and specific dosing regimens, baseline nutritional status, and objective immune markers are not quantified in the text.
Cited by
- supports Glutamine supplementation reduces the incidence of upper respiratory tract infections in endurance runners.