Sauna — 15 Min
The body's thermoregulatory system engages. Heat shock proteins activate, blood vessels dilate, and circulation expands across the periphery. The parasympathetic nervous system begins to dominate. This stage primes the tissue and cardiovascular system for the contrast that follows.
Increased
- ↑Heat Shock Proteins
- ↑Circulation
- ↑Vasodilation
- ↑Parasympathetic Tone
Decreased
- ↓Muscle Tension
- ↓Sympathetic Activity

