Growth hormone release during acute and chronic aerobic and resistance exercise: recent findings.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing physiological findings without systematic review methodology.
PubMed 12457419 · doi:10.2165/00007256-200232150-00003
What was done
This narrative review summarizes research on acute and chronic growth hormone (GH) secretory responses to aerobic and resistance exercise across different age groups, sexes, and body composition profiles.
What was found
Acute GH secretion increases linearly with exercise intensity regardless of age or gender, rather than requiring a threshold intensity. Acute GH release is higher in young women than in young men and is reduced 4- to 7-fold in older individuals compared with younger individuals. A single aerobic bout does not usually elevate 24-hour integrated GH concentrations due to a subsequent transient decrease in secretion, but repeated bouts within 24 hours do increase 24-hour integrated levels. In young women, chronic aerobic training above the lactate threshold led to a 2-fold increase in 24-hour GH release. Resistance exercise produces acute increases in GH release similar to aerobic exercise, but data on 24-hour pulsatile responses are limited.
Why it matters
This review clarifies how exercise modality, intensity, and frequency modulate endogenous GH secretion, demonstrating that modifying sustained 24-hour GH output requires repeated daily sessions or high-intensity chronic training.
Limits
As a narrative review, it lacks systematic search methodology and risk-of-bias evaluation. Methodological challenges, including maintaining patent intravenous catheters during resistance exercise, limited available 24-hour pulsatility data. Long-term clinical outcomes and causal links between exercise-induced GH changes and health endpoints in aging or obesity remain unestablished.
Cited by
- supports Moderate-to-high-intensity exercise causes a substantial acute spike in growth hormone secretion.