HPTA

HPTA (hypothalamic-pituitary-thyroid-adrenal axis) names the brain-pituitary-thyroid-adrenal loop that sets metabolic rate and stress-hormone output. Endocrinology often splits this into separate HPA and HPT axes; Peat wrote about them as one stress-energy system.

When the diet has chronically contained more polyunsaturated fats than can be oxidized immediately or detoxified by the liver, the fat stores will contain a disproportionate amount of them... These PUFA stimulate the stress hormones, ACTH, cortisol, adrenaline, glucagon, and prolactin, which increase lipolysis, producing more fatty acids in a vicious circle. In the relative absence of PUFA, the stress reaction is self limiting.

— Ray Peat

The maladaptive sequence, starting from stress or hypothyroidism, would typically involve increased absorption of endotoxin, leading to interference with mitochondrial respiration, a shift to fat oxidation, inflammation, and the increase of a wide range of stress hormones.

— Ray Peat

Chronic Stress keeps thyroid output low and shifts cells toward glycolytic Lactic acid production in Peat's writing. Intense exercise raised cortisol, prolactin, and estradiol acutely in athletes: interval running to exhaustion produced immediate post-exercise increases of 45% in estradiol, 38% in testosterone, and 230% in prolactin. Aspirin blunted several exercise-related pituitary hormone spikes in a human RCT. Recovery themes: adequate Thyroid, Progesterone, Glucose, salt, lower PUFA, Aspirin, niacinamide, reduced gut Endotoxin. See Cortisol, Hypothyroidism, Roadmap/06 - Activities, Harm reduction.