Research

Hormonal

GH improves exercise capacity in GHD through increased oxygen delivery (cardiac output, blood volume) and substrate availability (fat oxidation), not primarily through increased muscle strength.

GH replacement works by improving how your heart pumps blood and how your body burns fat during exercise, rather than just building bigger muscles.

GoodSupportsHIGH confidence
probably through some combination of increased oxygen delivery to exercising muscle, increased fatty acid availability with glycogen sparing, increased muscle strength, improved body composition, and improved thermoregulation.
James Gibney et al. · Endocrine Reviews · 2007

Why this rating

Supported by multiple physiological studies cited.

Source

The Growth Hormone/Insulin-Like Growth Factor-I Axis in Exercise and Sport

James Gibney et al. · Endocrine Reviews · 2007

DOI 10.1210/er.2006-0052

narrative_reviewCited 177×
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DOI resolved against Crossref · corpus check 2026-06-10

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