For people who don't want the brochure. The science, the experience, the things floaters swear by — and the honest line between what's been proven and what hasn't.
This page is not for the casual reader.
If you're new to floating, start with the main Floating page. It covers what the tank is, what to expect your first time, and why people walk out lighter than they walked in. Read that first. This page assumes you've been there.
Here, I want to go further. I'll walk through what 30 days of daily floating did to my body and brain — measured, not estimated. Then we'll go into what science has actually proven about floating, and what it hasn't. Finally, we'll look at what people consistently report — athletes, entrepreneurs, performers, clinical patients — even where the research hasn't caught up yet.
This is a long read. There are citations, dropdowns, and places where I tell you what science doesn't yet know as much as what it does. If you're looking for a quick pitch on floating, you won't find one here — and that's the point. Float Boston exists because floating is worth taking seriously. So that's how I'm going to talk about it.
I'm Mark. I own Float Boston. In February and March of 2026, I floated every day for 30 days and tracked everything — Oura ring data, blood draws at Quest Diagnostics, daily journal entries. Real numbers, not vibes. Here's what I'm comfortable saying about what changed.
30-day deltas — Oura ring averages and Quest Diagnostics blood draw comparison.
My high-sensitivity C-reactive protein went from 6.4 mg/L to 2.0 mg/L over 30 days. hs-CRP is one of the most well-studied markers of systemic inflammation, and mine started in the higher cardiovascular-risk range. After a month of daily floating, it had dropped into the average range. That's not a small move. That's a measurable change in how my body was managing inflammatory load.
I want to be honest about what this means and what it doesn't. I didn't change my diet. I didn't take new supplements. I worked more, not less. The one thing I did differently was float every day. That's not proof of mechanism — that's a personal experiment. But the data is what it is.
My HRV trend climbed 33%. My readiness score climbed 8 points. Stress minutes fell. Restorative minutes jumped 43% — during a week I worked more than the previous several months combined. That's the part that matters most to me. Nothing in my life slowed down. I responded to it differently.
Here's what surprised me, day to day: I stopped needing background noise. Podcasts in the car. TV on at home. I had been running constant audio for years. By week two I'd stopped. I was reading more and watching less. I wasn't yelling at Boston drivers. The world felt slower without anything in it actually slowing down.
On day three, I had what I'd call the best float of my life. Total quiet. I came out and stayed calm for hours — life moving at an absurdly slow pace, almost like I was on an island somewhere. On day six, in the first 15 minutes, I solved a persistent operations problem that had been bothering me for months. I watched my brain assemble it like a 3D puzzle. Then everything went purple. Faces, shapes, a hue that wrapped my body. I sat in our massage chair afterward in the dark for 20 minutes processing what had just happened.
This isn't unusual. Researchers have documented altered states of consciousness during floating across multiple studies — visual phenomena, distorted time perception, the dissolution of body boundaries. The science is starting to catch up to what floaters have been describing for 50 years. More on that in section two.
I've always been a creative person — if only you could see my dreams. But I've always had a difficult time putting my ideas and thoughts to paper. I'd tried and failed at writing at least five books, because what I could put down was never what I saw in my head.
Then I floated. Within eight months of regular floating, I turned my 20-year dream of publishing a book into reality and self-published my first one. Self-plug here — you can read a little of it at thehumbeneatheverything.com.
That's just one of dozens of examples of how floating has helped my creativity. It's helped me solidify marketing strategies for Float Boston and my other ventures. It's let me work through complex problem-solving. It's even helped me articulate my feelings to other people — which, let's face it, isn't easy.
When I first started floating, all I saw was darkness, and my mind never stilled. Now I've learned to control the float narrative. What I've found are three phases — though I'm sure there are more I haven't cracked into yet.
This is where my mind won't stop. I think about everything and nothing all at once. Although the mind is racing, the body is healing. Aches, pains, stressors, tension — all of it starts to melt away. Most first-time floaters spend the entire session here, and that's exactly as it should be.
There comes a point where everything turns off. A lot of people come to this darkness and stay there, and that's absolutely perfect. This is where your mind quiets, your body becomes completely still, and you can almost hear the blood pumping through your veins. This is where emotional and spiritual healing get added to the physical. If you're floating for insomnia, stress, anxiety, or any emotional disorder, phase two is exactly where you want to be.
Phase three is different. I've learned that once you're in phase two, if you control your breath — slow inhale, hold, slow exhale, hold — and keep your eyes open, that's where the creative starts. You'll know you're there because you'll start to see things float above you. Stars, shapes, even faces. I've seen my body turn purple, red, and green in this state, and I've even learned how to control whatever it is I'm seeing. For lack of a better term: it's a trip.
So much more has happened in this phase that I can't articulate, and for those of you who get here — you know the feeling. If there's more, and you've experienced it, I'd love to hear about it. Email me at mark@floatboston.com.
After 30 days, the floater's high arrives in five minutes instead of twenty. My brain knows the shortcut now.
If you want the day-by-day account with every Oura score, every blood marker, and every odd thing that happened in the tank, the full 30-day record is here.
Floating has been studied since the 1950s. The research has been uneven — small sample sizes, inconsistent protocols, lots of self-reported outcomes — but the body of evidence has grown substantially in the last decade, particularly through the work of the Float Clinic and Research Center at the Laureate Institute for Brain Research, which has been running clinical trials on floating since 2014 and recently celebrated its 10th anniversary.
I'm dividing this into two buckets: what floating does inside (mental, emotional, nervous system) and what it does outside (physical, performance, recovery). I'll cite the studies. Where the evidence is strong, I'll say so. Where it's mixed or weak, I'll say that too.
This is the most well-supported clinical finding. A 2018 open-label trial at the Laureate Institute, led by Dr. Justin Feinstein, took 50 participants across the full spectrum of anxiety disorders — generalized anxiety, PTSD, panic disorder, social anxiety, agoraphobia — most with comorbid depression. A single one-hour float session produced a significant short-term reduction in anxiety and an antidepressant effect that persisted for over 48 hours after the float.(Feinstein et al., PLOS ONE, 2018)
A follow-up 2024 randomized controlled trial extended this to repeated sessions across 75 participants, finding the intervention safe, well-tolerated, and feasible for clinical use.(Garland et al., PLOS ONE, 2024)
Mechanism: floating reduces what researchers call exteroceptive sensory input — every signal coming in from the outside world is minimized at once. Visual, auditory, thermal, gravitational, proprioceptive. With nothing pulling at the nervous system, the parasympathetic branch (rest-and-digest) takes over. fMRI research has shown reduced activation in the amygdala — the brain's threat-detection center — which is the same target that anxiety medications try to reach, without the side effects.
A 2024 systematic review of flotation-REST research identified six studies showing stress reduction across both clinical and non-clinical populations.(Systematic review, PMC, 2024) Earlier work from Feinstein's group established that floatation acutely reduces cortisol, muscle tension, and blood pressure — three of the four most commonly used objective stress markers.
Six studies have specifically examined what happens to consciousness during a float. The findings are remarkably consistent: visual and auditory phenomena, distorted time perception, dissolution of body boundaries, occasional out-of-body experiences, and what participants describe as personally transformative visions. These aren't rare side effects — they're what floaters routinely report. The science treats them as features of the experience, not malfunctions of it.
Five studies have shown improvements in originality, divergent thinking, and aspects of musical creativity (improvisation, composition) after floating. Sample sizes have been small, but the direction of effect has been consistent across decades of research.
Active clinical trials investigating floatation-REST for PTSD are ongoing in the United States, Germany, and Sweden. Earlier-phase studies have shown promising short-term effects on hyperarousal and intrusive thoughts, but long-term controlled trials are still in progress. Strong rationale, growing evidence base — but I won't tell you it's settled.
Most depression research on floating has been bundled into anxiety/depression studies. The Feinstein 2018 work found significant reductions in depression alongside anxiety in comorbid populations, but standalone depression trials are smaller. The signal is real but the evidence base is younger than the anxiety literature.
The Laureate Institute has run early-phase trials specifically on flotation-REST for anorexia, examining body image and anxiety in patients. Published results are encouraging but the population is small and specialized.(Khalsa, Moseman et al.)
Mixed. Some studies have shown improvements in sleep onset and quality; others haven't. The 2024 systematic review concluded floating has "limited to no effect" on sleep-related disorders specifically — though many floaters anecdotally report better sleep, possibly downstream of stress reduction rather than direct sleep effects. My own 30-day data showed clear sleep improvements, for what that's worth.
Some early enthusiasm in the 1980s and 90s, no replicated results since. Honest answer: there's no good reason to think floating will help you quit smoking, and the research bears that out. If anyone tells you otherwise, ask for the citation.
A 2019 study published in the Journal of Bodywork and Movement Therapies took 19 trained team-sport athletes through a controlled exercise protocol followed by either one hour of floating or one hour of passive recovery. They measured strength (mid-thigh pull), explosive power (countermovement jump), sprint speed, salivary cortisol, and sleep via wrist actigraphy. The float group showed improved sleep and faster recovery of perceptual measures of muscle soreness.(Driller & Argus, 2019)
The 2024 systematic review identified eight studies on flotation-REST for athletic performance, with seven of the eight showing significant benefits — five on performance directly and two on post-exercise recovery. This is one of the more consistent areas of the literature.
Mechanism is twofold. The magnesium-saturated water relaxes muscles directly (Epsom salt is magnesium sulfate, and skin absorbs it during long submersion). Meanwhile, the absence of gravity loads off joints, spine, and connective tissue for the duration of the session. NFL teams, NBA teams, and Olympic programs have integrated float tanks into recovery protocols — the New England Patriots, Los Angeles Rams, Boston Celtics, and Ohio State football among them.
Less directly studied than the nervous system effects, but my own n=1 result (hs-CRP 6.4 → 2.0 in 30 days) is consistent with the broader hypothesis that chronic stress drives inflammation, and reducing stress reduces inflammation. The pathway is well-established in the broader literature on stress, cortisol, and immune function. The specific contribution of floating to anti-inflammatory effects has not yet been the subject of large randomized trials, but the indirect chain of reasoning is strong.
This is where I have to be careful. A 2001 study showed flotation-REST improved muscle tension pain in the neck and back.(Kjellgren et al., Pain Research and Management) Multiple studies since have shown short-term pain relief.
However: a 2021 randomized clinical trial from Hannover Medical School in Germany — the first to use an indistinguishable placebo control — found no long-term benefits from five flotation sessions for chronic pain patients, and noted that the placebo group showed clinically relevant short-term improvements as well.(JAMA Network Open, 2021) The authors concluded that pain improvements may not be caused by stimulus restriction or effortless floating specifically — meaning some of what we attribute to "the float" may be the effect of an hour of complete rest in any form.
What I'd say honestly: floating likely helps pain in the short term. Whether it does so through specific mechanisms or through generic deep-rest effects is unsettled. Either way, the relief is real for many people; the open question is what's actually driving it.
Feinstein's early work established acute reductions in blood pressure during and after floats. Long-term cardiovascular trials at scale haven't been done.
Reasonable evidence for short-term relief. Mechanism is straightforward — gravity-loaded postures are the proximate cause of much chronic muscle tension, and floating eliminates gravity loading entirely for the session. The Driller athletic studies showed measurable reductions in perceived muscle soreness post-float.
Acute reductions during and immediately after floating are well-documented in Feinstein's work. Long-term hypertension management trials don't exist yet.
Anecdotal reports are abundant; controlled studies are sparse. Plausible mechanism — stress and tension are major migraine triggers — but I won't tell you the science is settled here.
An international Fibromyalgia Flotation Project has been collecting data for over a decade, with initial results suggesting flotation-REST helps participants relax, manage pain, and attend to daily tasks. The methodology has been more participatory than tightly controlled, so I'd treat this as suggestive rather than conclusive.
Many float centers (including ours) accommodate floating during pregnancy. The unweighting of the body is reportedly profound for women carrying a baby. There's no formal RCT literature here — this is an "ask your OB" situation, and we ask too before each session.
Some of what floaters report has not been systematically studied. That doesn't mean it's not real — it means science hasn't gotten to it yet, or the study designs needed to capture it haven't been built. What's striking is how consistent these reports are across people who otherwise have nothing in common: athletes, comedians, entrepreneurs, performers, clinical patients. Different worlds, same descriptions.
Here are some of the figures whose accounts I find hardest to dismiss.
Joe Rogan has been the most public advocate for floating for over a decade — credited by industry insiders as a major driver of the modern float renaissance. He's described the sensory deprivation chamber as the most important tool he's used for thinking and personal evolution, and talks about the float as a process that surfaces every issue in his life he's been avoiding before letting him see the bigger picture once those issues are out in the open. His simple recommendation: "Everybody should do the tank."
Stephen Curry has used floating to manage the cognitive load of being one of the most-watched athletes in the world. He's described the experience in interviews and a Kaiser Permanente commercial as a way to slow his mind and step away from the constant pressure. According to one Bay Area float spa, Curry tries to float roughly every two weeks. The same year he set the NBA single-season three-point record, he was the spa's most frequent client.
Tim Ferriss, who has interviewed hundreds of high performers across every domain, has described floating as one of the most anxiety-reducing experiences he's ever tried. In Tools of Titans, he points to floating as a recurring tool among elite performers for stress reduction, problem-solving, and creative work. He's used the tank as a "blank slate" to surface old memories — including, in one striking example, reactivating dormant language skills he hadn't practiced in years.
Bill Belichick reportedly learned about float tanks during a 2014 visit with U.S. Special Forces and brought the technology to the New England Patriots. By Super Bowl LI, much of the roster was floating regularly — Tom Brady, Julian Edelman, Matthew Slater, Chris Hogan, Dont'a Hightower. Brady had a commercial-grade tank installed in his home. The team's offensive coordinator told reporters the tanks gave players the equivalent of four hours of rest in roughly 45 minutes. By 2019, three of the four NFL conference championship teams were using float tanks in some form.
Olympic gymnast Aly Raisman has spoken publicly about her use of float tanks. Olympic swimmers, runners, and gymnasts across multiple programs have integrated floating into training routines. Beyond individuals: the Boston Celtics, the Los Angeles Rams, the New Orleans Saints, the Ohio State football program, Notre Dame, and Clemson have all installed tanks in team facilities. Whatever the mechanism, organizations whose entire job is to find anything that gives a one-percent edge keep finding floating worth their athletes' time.
Across all these accounts and thousands more like them — clients who've told me their experiences over the last year, posts on the floating subreddits, interviews with Float Boston regulars — the same things keep coming up. Not as marketing claims. As patterns:
Float tanks were invented in 1954 by John C. Lilly, a neuroscientist at the National Institute of Mental Health studying consciousness. Lilly believed the tank was, fundamentally, a tool for exploring the mind — that what people experienced during deep floats wasn't a side effect but the point. He was a contemporary of Timothy Leary and Allen Ginsberg, and his views on consciousness placed him outside the mainstream of his era's neuroscience.
Modern researchers are now circling back to questions Lilly was asking 70 years ago: what happens to the default mode network during a float? What's the neurological basis of the boundary dissolution that floaters describe? Why do creative insights arrive so reliably in this state? These aren't fringe questions anymore — they're active research programs at major universities, and the evidence base is growing every year.
The honest answer: we don't yet know everything about why floating does what it does. But the people who do it consistently — across athletics, business, performance, creative work, and clinical populations — keep reporting the same things. Eventually the research will catch up. In the meantime, the experience speaks for itself.
If you've read this far, one float won't be enough. The states this page describes — phase two and beyond — take repetition. Our Go Deeper package is built for it.
3 floats · $150 →That's $50 a float — about a third off our standard rate.
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