What does Flotation-REST do to the body?
In studies of people floating for chronic muscle-tension pain, blood pressure has been measured to decrease, alongside a fall in MHPG, a breakdown product of the stress chemical noradrenaline that tracks how activated the nervous system is (Kjellgren et al., 2001), (Bood et al., 2005). Endorphin levels stayed unchanged in the same work, which argues against a simple painkiller effect. In the body, this downshift often feels like a heavy, warm settling, the shoulders and jaw letting go, and a sense that the background push to stay alert has quieted.
Blood Pressure
direct EVIDENCE
Many floaters feel a heavy, warm settling through the body, as if the constant push to stay alert has quieted. In people who floated regularly for stress-related muscle pain, blood pressure, the force of blood pushing against the vessel walls, has been measured to fall, alongside a drop in a noradrenaline breakdown product that tracks how activated the nervous system is (Kjellgren et al., 2001), (Bood et al., 2005).
Sympathetic Activation
moderate EVIDENCE
During a float, the wired, on-guard feeling tends to ease. In people with chronic, stress-related muscle-tension pain, floating was measured to lower sympathetic arousal, the body's fight-or-flight setting, with reduced blood pressure and less of a noradrenaline breakdown product, the stress chemistry behind feeling revved up (Kjellgren et al., 2001), (Bood et al., 2005). Practitioners often describe this as the body downshifting out of high gear: shoulders dropping, breathing slowing, and the sense of bracing letting go.
Normalised Stress Hormone Levels
moderate EVIDENCE
The wired, on-alert feeling of stress can ease during floating. In a small study of people with chronic muscle-tension pain, a marker of adrenaline-type arousal called MHPG decreased and blood pressure dropped after flotation sessions, while endorphin levels stayed the same (Kjellgren et al., 2001), (Bood et al., 2005), changes practitioners often experience as the body feeling less revved-up and tension quietly letting go.
Muscle Tension
moderate EVIDENCE
The braced, tight feeling in the neck, shoulders, and jaw can ease as the warm salt water carries your full weight. In small studies of people with chronic neck and back pain, the flotation group reported lower muscle-tension pain alongside a reduced marker of nervous-system arousal, while a comparison group did not (Kjellgren et al., 2001), (Bood et al., 2005).
