Overview of Flotation-REST Research (2025)

A 2024 systematic review identified 63 studies encompassing 1,838 participants from 1960 to May 2024 [1], categorizing flotation-REST research into nine main areas: pain, athletic performance, physiology, stress, consciousness, psychology, creativity, clinical anxiety, sleep, smoking cessation, and miscellaneous applications.

Key Research Findings by Domain for Flotation-REST

1. Mental Health & Anxiety (Strongest Evidence)

   Studies with anxious participants showed substantial reductions in state anxiety with effect sizes greater than 2, accompanied by significant decreases in stress, muscle tension, pain, depression, and negative affect [2]. A randomized controlled trial for generalized anxiety disorder (GAD) found that 12 flotation sessions produced strong beneficial effects, with 43% of participants becoming "good sleepers" at post-treatment compared to 27% in controls, and the treatment showed the strongest effect for depression with 42% of participants achieving full remission compared to 9% in the control group [3].

   
   

   The first neuroimaging study of flotation-REST revealed decreased functional connectivity between somatomotor and default-mode networks, suggesting the intervention reduces bodily self-awareness and mental rumination [4]. Relative to a comparison condition, flotation-REST generated significant anxiolytic effects characterized by reductions in state anxiety and muscle tension and increases in feelings of relaxation and serenity, with all variables showing significance at p < .001 [5].

   
   

2. Pain Management

   Flotation-REST treatment elevated participants' optimism and reduced anxiety or depression; at nighttime, patients who underwent flotation fell asleep more easily, with patients suffering from chronic pain reporting they had forgotten their pain while floating [6]. Analyses of 88 patients with chronic stress-related muscle tension pain indicated that flotation-REST treatment had beneficial effects on stress, anxiety, depression, sleep quality and pain, with few sex differences between men and women [7].

   
   

   However, one rigorous single-blind randomized clinical trial comparing flotation-REST with an indistinguishable placebo and wait-list control found that patients with chronic pain experienced no long-term benefits from five flotation-REST interventions, with clinically relevant short-term changes in pain occurring in the placebo group as well, suggesting improvements may not be caused by environmental stimulus restriction or effortless floating as previously thought [8].

   
   

3. Cardiovascular & Physiological Effects

   Flotation-REST significantly reduced blood pressure throughout the float session, with average systolic blood pressure reducing by approximately 5 mm Hg and diastolic blood pressure showing a more pronounced reduction of approximately 13 mm Hg that occurred quite rapidly, often within the first 5 minutes of the float session, reaching the lowest point during the diastole phase with an average reduction greater than 12 mm Hg [5]. Studies generally found flotation-REST produced various physiological effects indicative of decreased sympathetic arousal, such as reduced blood pressure, slowed breathing rate, and decreased cortisol levels [1].

   
   

   A controlled study measuring electromyogram (EMG), galvanic skin response (GSR), peripheral skin temperature, and blood pressure found that flotation REST significantly enhanced point-to-point relaxation, breathing techniques, and visual imagery techniques, with the experimental group showing greater reductions in systolic and diastolic blood pressure from pre-test to post-test [9].

   
   

4. Athletic Performance & Recovery

   A study examining flotation-REST following maximal eccentric exercise found that it had a significant impact on blood lactate and perceived pain compared with a 1-hour passive recovery session in untrained healthy men, though no difference was found between conditions for muscle strength, blood glucose, muscle soreness, heart rate, or perceived exertion [10].

   
   

   Elite international-level athletes across nine sports who completed approximately 45-minute flotation sessions following exercise training showed improvements in mood-state variables and perceived muscle soreness, with 27 athletes napping during the session [11]. Because no adverse effects and significant and meaningful benefits were observed in trained men following high-intensity resistance exercise, flotation-REST may prove a valuable intervention for managing soreness and enhancing performance readiness after exercise [12].

   
   

5. Creativity & Cognitive Function

   Five studies investigating the effects of flotation-REST on creativity found that it generally enhances creativity, with one study showing improvements in scientific creativity, one showing increased divergent thinking, one showing improved technical musical ability, and two showing increased originality, though one also found flotation-REST may impair creative problem-solving, with all five studies (100%) finding at least some significant result in favor of creativity-enhancing effects [13].

   
   

   Studies using chain puzzles, paper-and-pen tests measuring fluency, obvious answers, original answers, elegance and deductive thinking found impaired creative problem-solving ability and higher originality for the floating group, interpreted as an indication of cognitive function where the primary process still dominates over the secondary process [14].

   
   

6. PTSD & Trauma

   This was the first flotation-REST trial in individuals across the spectrum of anxiety and depression, with results showing clear signs of short-term benefit in PTSD, generalized anxiety disorder, panic disorder, agoraphobia, social anxiety disorder, and major depression [2]. In clinical settings, REST has been proposed as a treatment for various conditions, including anxiety disorders, chronic pain, and post-traumatic stress disorder (PTSD), with flotation sessions potentially used as a complementary therapy for a range of psychological and mental health conditions combined with other therapies such as counseling and medication [13].

   
   

7. Sleep (Limited Evidence)

   A study investigating flotation-REST as an insomnia treatment in six participants with insomnia diagnosis showed mixed results, with flotation-REST potentially beneficial for young adults with sleep-onset insomnia but warranting more research [15]. In general, flotation-REST was found to bring about positive effects on pain, athletic performance, stress, mental well-being, and clinical anxiety, while having limited to no effect on sleep-related disorders and smoking cessation [1].

   
   

Mechanisms of Action

Research suggests flotation-REST works through multiple pathways:

• The float environment significantly enhanced awareness and attention for cardiorespiratory sensations, inducing a state of relaxation and heightened interoceptive awareness in a clinical sample with high anxiety sensitivity [5].

• Functional neuroimaging investigation found that flotation-REST leads to altered patterns of resting-state functional connectivity, with decreased functional connectivity between somatomotor and default-mode networks [4].

• Flotation-REST produces physiological effects indicative of decreased sympathetic arousal, such as reduced blood pressure, slowed breathing rate, and decreased cortisol levels [1].

• The intervention reduces sensory input to the nervous system through floating supine in water saturated with Epsom salt, with sensory signals from visual, auditory, olfactory, gustatory, thermal, tactile, vestibular, gravitational and proprioceptive channels minimized, as is most movement and speech [2].

  
  

Current Limitations

A limitation of the systematic review is the relatively small number of studies available, which limits the generalizability of certain findings and highlights the need for additional research in this area [1]. Additional concerns identified across studies include:

• Small sample sizes in many studies

• Lack of long-term follow-up data

• Inconsistent treatment protocols (session duration, frequency, total number)

• Limited placebo-controlled designs, with one study noting this was the first to compare flotation-REST directly with an indistinguishable placebo in patients with chronic pain [8]

• Unclear optimal dosing parameters

  
  

Critical Future Research Needs

High Priority Areas:

1. Mechanism Studies: More research is needed to better understand the mechanisms underlying these effects and to identify optimal treatment protocols for different populations [1]. This includes:

   • Additional functional neuroimaging investigations beyond the first study [4]

   • Biomarker studies (cortisol, inflammatory markers, neurotransmitters)

   • Investigation of whether improvements are caused by environmental stimulus restriction or effortless floating versus placebo effects [8]

2. Dose-Response Research: Determine optimal:

   • Session duration (30, 60, 90+ minutes)

   • Treatment frequency and total number of sessions, building on the 12-session protocol used for GAD [3]

   • Maintenance protocols for sustained benefits

3. Large-Scale RCTs: Well-powered randomized controlled trials with:

   • Adequate sample sizes beyond current studies

   • Active and placebo control conditions, following the model of placebo-controlled designs [8]

   • Long-term follow-up (6-12+ months)

   • Standardized outcome measures

   • Cost-effectiveness analyses

4. Population-Specific Research:

   • Children and adolescents

   • Elderly populations

   • Further investigation of sex differences in treatment response [7]

   • Specific clinical populations (fibromyalgia, chronic fatigue, autoimmune conditions)

   • Special Operations Forces Operators and elite athletes [16]

5. Combination Therapy Studies: Integrating flotation with mindfulness practices, Cognitive Behavioral Therapy, yoga, breathwork techniques, massage, creative expression through art or music therapy, acupuncture, and biofeedback techniques [17].

6. Sleep Disorder Research: Despite limited current evidence for sleep-related disorders [1], the relationship between flotation and sleep requires deeper investigation with objective sleep measurements and larger samples.

7. Safety & Contraindications: Comprehensive safety and feasibility trials to assess adherence rates, tolerability via duration of REST utilization, overall study dropout rates, and incidence of serious or non-serious adverse events across different formats [18].

8. Implementation Science: Research on:

   • Scalability and accessibility

   • Training requirements for practitioners

   • Integration into existing healthcare systems

   • Patient adherence and dropout factors

     
     

Emerging Areas:

• Neuroplasticity: Long-term brain changes with regular flotation

• Immune Function: Effects on inflammatory markers and immune response

• Addiction Treatment: Building on limited effectiveness for smoking cessation [1]

• Performance Enhancement: Applications beyond athletics (cognitive, creative professionals)

  
  

While flotation-REST appears to induce various benefits for physical and mental well-being, particularly when it comes to managing states like pain and stress [1], the field requires more rigorous, large-scale research to establish flotation-REST as an evidence-based intervention across its proposed applications.

References

1. Lashgari E, Winnubst P, Poirazi P, Roelfsema PR, Guo K. A systematic review of flotation-restricted environmental stimulation therapy (REST). BMC Complement Med Ther. 2025 Jul 3;25(1):188. doi: 10.1186/s12906-025-04973-0. PMID: 40611079.

2. Feinstein JS, Khalsa SS, Yeh HW, Wohlrab C, Simmons WK, Stein MB, Paulus MP. Examining the short-term anxiolytic and antidepressant effect of Floatation-REST. PLoS One. 2018 Feb 2;13(2):e0190292. PMID: 29394251.

3. Jonsson K, Kjellgren A. Promising effects of treatment with flotation-REST (restricted environmental stimulation technique) as an intervention for generalized anxiety disorder (GAD): a randomized controlled pilot trial. BMC Complement Altern Med. 2016 Mar 25;16:108. doi: 10.1186/s12906-016-1089-x. PMID: 27016217.

4. Al Zoubi O, Misaki M, Bodurka J, Kuplicki R, Wohlrab C, Schoenhals WA, et al. Taking the body off the mind: Decreased functional connectivity between somatomotor and default-mode networks following Floatation-REST. Hum Brain Mapp. 2021;42(10):3216-27. doi: 10.1002/hbm.25429.

5. Feinstein JS, Khalsa SS, Yeh H, Al Zoubi O, Arevian AC, Wohlrab C, Pantino MK, Cartmell LJ, Simmons WK, Stein MB, Paulus MP. The Elicitation of Relaxation and Interoceptive Awareness Using Floatation Therapy in Individuals With High Anxiety Sensitivity. Biol Psychiatry Cogn Neurosci Neuroimaging. 2018 Jun;3(6):555-562. doi: 10.1016/j.bpsc.2018.02.005. PMID: 29656950.

6. Kjellgren A, Sundequist U, Norlander T, Archer T. Effects of flotation-REST on muscle tension pain. Pain Res Manag. 2001 Winter;6(4):181-9. doi: 10.1155/2001/768501. PMID: 11854763.

7. Kjellgren A, Bood SÅ, Axelsson K, Norlander T, Saatcioglu F. Treating stress-related pain with the flotation restricted environmental stimulation technique: are there differences between women and men? Pain Res Manag. 2004 Winter;9(4):176-84. doi: 10.1155/2004/768501. PMID: 19714269.

8. Kjellgren A, Sundequist U, Sundholm U, Norlander T, Archer T. Flotation Restricted Environmental Stimulation Therapy for Chronic Pain: A Randomized Clinical Trial. JAMA Netw Open. 2021 May 3;4(5):e219627. doi: 10.1001/jamanetworkopen.2021.9627. PMID: 33988708.

9. Jacobs GD, Heilbronner RL, Stanley JM. The effects of short term flotation REST on relaxation: a controlled study. Health Psychol. 1984;3(2):99-112. PMID: 6399246.

10. Morgan WP, Salacinski AJ, Stults-Kolehmainen MA. The acute effects of flotation restricted environmental stimulation technique on recovery from maximal eccentric exercise. J Sports Med Phys Fitness. 2013 Oct;53(5):511-20. PMID: 23478477.

11. Driller MW, Argus CK. Flotation restricted environmental stimulation therapy and napping on mood state and muscle soreness in elite athletes: A novel recovery strategy? Perform Enhanc Health. 2016 Oct;5(2):60-65. doi: 10.1016/j.peh.2016.08.002.

12. Caldwell LK, Post EM, Beeler MK, Dickerson RM, Kraemer WJ. Acute Floatation-REST Improves Perceived Recovery After a High-Intensity Resistance Exercise Stress in Trained Men. J Strength Cond Res. 2022 Aug;36(8):2248-2254. doi: 10.1519/JSC.0000000000003783. PMID: 35389942.

13. Lashgari E, Winnubst P, Poirazi P, Roelfsema PR. A systematic review of Flotation-Restricted Environmental Stimulation Therapy (REST). medRxiv. 2023 Nov 30. doi: 10.1101/2023.11.29.23299203.

14. Norlander T, Bergman H, Archer T. Effects of Flotation REST on Creative Problem Solving and Originality. J Environ Psychol. 1998;18(4):399-408. doi: 10.1006/jevp.1998.0112.

15. Norell-Clarke A, Jonsson K, Blomquist A, Ahlzén R, Kjellgren A. A study of flotation-REST (restricted environmental stimulation therapy) as an insomnia treatment. Sleep Sci. 2022 Apr-Jun;15(Spec 2):361-368. doi: 10.5935/1984-0063.20210012. PMID: 35371408.

16. Barton JL, Kearney EP, Crowley SK. Flotation-Restricted Environmental Stimulation Technique: A Proposed Therapy for Improving Performance and Recovery in Special Forces Operators - A Narrative Review. J Spec Oper Med. 2022 Winter;22(4):86-94. doi: 10.55460/FHRU-WXRS. PMID: 36525015.

17. Lashgari E, Winnubst P, Poirazi P, Roelfsema PR, Guo K. A systematic review of flotation-restricted environmental stimulation therapy (REST). BMC Complement Med Ther. 2025;25(1):188.

18. Khalsa SS, Moseman SE, Yeh HW, Upshaw V, Persac B, Breese E, Simmons WK, Paulus MP, Feinstein JS. A randomized controlled safety and feasibility trial of floatation-REST in anxious and depressed individuals. Sci Rep. 2023 Jun 14;13(1):9657. doi: 10.1038/s41598-023-36306-3. PMID: 37316540.