Stress Test: Float Therapy Relieves Shoulder Tension

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Stress Test: Float Therapy Relieves Shoulder Tension

Stress Test is a series about the science behind our busy lives and how stress affects our bodies. The biweekly column uncovers the latest research and explains how to put it to use in a practical way. Look for the science behind epigenetic markers of stress, mindfulness, meditation and deep brain stimulation.


Float therapy shops are becoming the new retail trend similar to the frozen yogurt and cupcake stores of the past few years. New locations seem to be popping up everywhere, at least where I’m located, and people are beginning to include them in their regular beauty and health care routines in the same way they book monthly trips to nail and hair salons.

Flotation tanks, also known as sensory deprivation tanks, contain more than 800 pounds of medical-grade Epson salt dissolved into about a foot of water. With that much salt, your body floats effortlessly as if you’re lounging in the Dead Sea, and the warm water and air envelop you at body temperature. Built to be light and sound proof, the floating experience removes stimuli and reduces sensory input. The 60- to 90-minute sessions are touted as a way to release tension, reach a deep meditative state quickly and boost creativity.

Invented in the 1950s by neuroscientist John Lilly, flotation tanks were originally used to study how sensory deprivation changed the mind. Now research about the “restricted environmental stimulation technique (REST), ” which popped up again in the early 1980s, investigates the various ways it can help your stress, injuries and muscle tension. In fact, in March last year, Swedish psychologists piloted a controlled trial (considered the “gold standard” in medicine) to test whether floating helps generalized anxiety disorder. Looks like it does.

With that in mind, when I heard a few weeks ago that a float therapy location was near my town, I decided to kick off 2017 the right way. My business partner and I closed our shop for an afternoon to try it out. When we walked inside, the lobby area resembled a typical spa entrance. Separate rooms held each floatation tank, complete with a shower station, fluffy towels and fragrant soaps and shampoos. The float pod itself is long enough to fit a tall man, wide enough to stretch out your arms, and deep enough to comfortably sit up, so 8 feet by 4 feet by 4 feet. Most designs are spacious enough to not worry about claustrophobia, equipped with door handles and lights that can be controlled from the inside.

The initial 10 minutes of the first hour-long session are all about adjusting — How do I do this? Is my head floating correctly? Where do I put my arms? Why is my heartbeat so loud? Then depending on your state of mind, you may lay there comfortably, drift into a meditative state or fall asleep. My business partner slipped into a sleepy state that nearly lulled her into a nap, and I spent time stretching and moving my arms and legs in the water, hearing my back and hips pop into place. The experience seems to vary by person and how many times they’ve gone before. There’s no doubt, though—we emerged with tension-free shoulders and calmer looks on our faces. The real trouble was driving back home and making ourselves get back to work.

Based on the latest studies, these are five benefits you may experience if you decide to relax in salty warm water, too:

1. Reduced anxiety and stress

Naturally, as the muscles that hold your posture relax, tension is lifted from all of the main areas where we carry stress physically, such as the shoulders, neck, back and hips. In the study mentioned above about anxiety, researchers found beneficial effects for emotional regulation and depression and some indication that it may help worrying as well. Other than depression, improvements continued six months after the experiment. Plus, increased cortisol levels that come with stress tend to decrease as well.

2. Relieved body tension

With that much salt in the water, the body actually floats in zero gravity. That’s the only way to experience zero gravity on the planet, which is why NASA uses flotation to simulate weightlessness during training. For those in chronic pain, such as fibromyalgia patients, flotation reduced muscle tension by a fourth with the first session and another third by the second session. The pain relief lasted more than two days. That’s not a unique finding—another study found it can help whiplash-associated disorder, and others have found that pain improves because levels of noradrenaline and blood lactate drop, which is good news for recreational and professional athletes with sore muscles. In fact, the float spa I went to near Athens, Georgia, had been visited by student athletes on the University of Georgia’s gymnastics, basketball and swim teams.

3. Lowered blood pressure

Floating at body temperature dilates the blood vessels and reduces blood pressure. Studies have specifically measured systolic and diastolic numbers and seen them drop significantly, even after one session. Plus, the water pressure on the skin under the water is lower than the blood pressure in the body, so blood flow improves in capillaries under the skin. And studies indicate it may not take many sessions—a Swedish paper says 12 sessions may be just as effective as 33 sessions, which seemed to be the upper limit for stress-related improvements.

4. Heightened creativity

About halfway through the float session, once the body is able to let go of sensory input and its responses, the brain shifts from alpha or beta waves into theta waves, which promote deep relaxation. This drop in electrical activity more directly connects the logical left brain and creative right brain, prompting more opportunities for creativity and focus. In several studies, researchers have found that college students felt more creative during and immediately after a float session. More specifically, college musicians improved jazz improvisation and composition following float therapy. Imagine an hour-long dip leading to the next greatest hit.

5. Broadened outlook

When the mind shifts to theta waves, it becomes more introspective, less defensive and more receptive, according to a study looking at the effects of flotation on addictive behaviors. The researchers piloted a controlled trial (that “gold standard” again) that found several sessions could modify smoking habits, and floating looks promising for overeating and alcohol consumption as well. As the mind steers away from stimuli and learns to go without the habit trigger, the body relaxes and focuses on the possibility of new habits.


Mentally, flotation benefits seem wide-ranging, but scientists are still looking at the physical benefits. Within the Epsom salt itself, the magnesium from the magnesium sulfate is absorbed through the skin, which can help with magnesium deficiency that we’re more prone to have from today’s Western diet. On the other hand, other studies measured several hormones and nucleic acids but showed no difference after floating. For example, even though floating improved sleep through relaxation, melatonin levels that affect sleep didn’t actually change. “The psychological consequences of flotation REST were more easily demonstrated than the neuroendocrine changes that are assumed to reflect the state of relaxation,” the study authors wrote.

So know what benefits you’re hoping to find. Also know that current studies are looking for differences among participants. Apparently, some differences could exist between men and women. In one study, women and men both benefitted, but women may have improved more because they were initially more depressed. Expect to see future studies in this area, too.

Images: Jon Roig, Flickr, CC-BY.

Carolyn Crist is a freelance health and science journalist for regional and national publications. She writes the Escape Artist column for Paste Travel, On the Mind column for Paste Science and Stress Test column for Paste Health.

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