The exercise-induced growth hormone response in athletes.
Level 5 - mechanism / opinion, no new human data
Narrative review of physiological mechanisms and exercise responses without systematic search or meta-analytic methodology.
PubMed 12797841 · doi:10.2165/00007256-200333080-00005
What was done
This narrative review synthesized literature examining the physiological mechanisms, acute responses, and chronic adaptations of the exercise-induced growth hormone response (EIGR) across resistance and endurance exercise modalities, as well as its relevance to aging athletes.
What was found
The abstract reports no numerical data or point estimates. Qualitatively, it reports that: - Resistance training elicits a significant EIGR governed primarily by load and frequency, with muscle protein synthesis largely mediated downstream via IGF-1 rather than direct GH receptor interactions alone. - For endurance exercise, an intensity threshold above the lactate threshold maintained for at least 10 minutes produces the strongest hGH secretory stimulus and may elevate 24-hour pulsatile release. - Chronic endurance training has equivocal effects, with evidence indicating decreased resting hGH and a blunted acute EIGR, possibly reflecting heightened peripheral tissue sensitivity. - The primary candidate mechanisms driving EIGR appear to be afferent neural stimulation, nitric oxide, and lactate production.
Why it matters
It outlines exercise dosing parameters (specifically high-intensity work above lactate threshold) to maximize natural, endogenous growth hormone secretion as a non-pharmacological alternative to exogenous GH administration and as a strategy to mitigate age-related functional decline.
Limits
The abstract describes a broad narrative overview rather than a systematic review; it does not provide study counts, sample sizes, effect sizes, or formal risk-of-bias assessments. The exact biological mechanisms driving EIGR and the chronic clinical impacts of training-induced GH changes remain unresolved.
Cited by
- supports Moderate-to-high-intensity exercise causes a substantial acute spike in growth hormone secretion.