Flotation-restricted environmental stimulation technique (Flotation-REST), is a form of sensory deprivation originally derived in the 1950s to investigate human consciousness in
the absence of external stimuli, including light, sound, and touch (Suedfeld, John Jr, and Fine,
2012). Floatation-REST involves lying supine in a light and soundproof tank with a shallow
saline solution of water and Epsom salts (Mg2SO4), maintained at approximate skin
temperature (~34°C), thus reducing visual, auditory, and sensory stimuli (Morgan, Salacinski
and Stults-Kolehmainen, 2013; Fine and Borrie, 2016).
This unique environment purportedly facilitates a relaxation response and the onset of sleep, alongside decompression of the musculoskeletal system and the restoration of homeostasis within the body (Bood et al., 2006; Driller and Argus, 2016; Hutchison, 2017).
Many studies have previously identified the health-related benefits of flotation-REST
in non-athletic populations including those suffering from stress, chronic pain, generalised
anxiety disorder and insomnia (Ballard, 1989; Kjellgren et al., 2001; Van Dierendonck and Te
Nijenhuis, 2005; Jonsson and Kjellgren, 2016).
The efficacy of flotation-REST as a stress management tool is generally accepted and well supported within literature as the intervention displays favourable psychophysiological adaptations including reduced cortisol, blood pressure and perceived stress in the only meta-analysis of the practice (Van Dierendonck and Te Nijenhuis, 2005).
It is worth noting that this standalone meta-analysis was faced with limitations including small sample sizes from the studies selected, consequently resulting in a high error variance. Moreover, the influence of sample bias is present, potentially due to studies without significant findings failing to get published.
The reduction of stress-related muscle tension and pain alongside sleep latency reduction and sleep quality enhancement are also documented within previous research (Ballard, 1989; Kjellgren et al., 2001). Additionally, flotation-REST has been shown to facilitate sport performance enhancement when combined with psychological interventions such as imagery and when used exclusively as a performance recovery intervention following athletic training (McAleney, Barabasz and Barabasz, 1990; Wagaman, Barabasz and Barabasz, 1991; Broderick, Uiga and Driller 2019).