 I'm a float enthusiast and have the opportunity to share some of the work that I've been doing with the use of float and exercise recovery. So I'm an exercise physiologist. My passion is really in understanding the role that exercise plays in both health and in human performance. And for the last few years, I've been particularly interested in this idea of appropriate recovery. When I was here a few years ago, we were just setting up our float tank out in the Kinesiology Department of Ohio State. Thank you, superior. And really setting the groundwork for this line of research. So it's so exciting to kind of come full circle, be back here with you guys, and share some of what we found so far. So recovery by definition really encompasses, it's really a multifaceted term, that encompasses both the restoration of physiological and psychological processes. So in a sport context, this really translates to an athlete's ability to handle the demands of their situation and maintain a high level of competitive and training performance. What are the demands on a competitive athlete? They're really complex. I think primarily we think in terms of physical stress, right? The volume, intensity, duration of training sessions, the length of a competitive season, the time between successive exercise bouts, and those are of critical importance. But they're not the only factors. Things like travel, time of day that the competition exists. These interact and interfere with normal sleep cycles. The environment that the competition is played in, heat, humidity, these are stressors. And then these immense psychosocial demands, the internal and external pressures to perform, coping with maybe being sidelined, the selection process, coping with injury, interactions with teammates, interactions with coaching staff, interactions with the media. Oh boy, social media and our poor athletes today. So we have to really understand. We have to kind of be able to monitor where does an athlete lie on this stress recovery continuum? And what can we do to make sure that they're better able to perform, right? What are some interventions to make sure that an athlete is recovered and able to perform at this peak level of performance? So I would say that there's three things that universally exercise scientists agree on. And that is the importance of adequate sleep, proper nutrition, and hydration. These are critically important factors at every stage of the competitive season, both in training, setting up the physiological profile for proper adaptation. And then we have the things that athletes are actually excited about. These acute interventions, the things that athletes use to feel better in the here and now, right? To manage pain, to manage soreness, to manage fatigue, particularly during the competitive season where we may only have a very short time frame between successive performances. But there are no magic bullets. We have to understand both the limitations of these interventions and how they can be used to adjust what we're looking for. What's the stress of the situation? What's going to be an appropriate recovery technique? In the last five to six years, we have seen a dramatic increase in the use of float therapy in high performance populations from the military to elite athletics. We've seen incorporation of float tanks into training rooms at the collegiate level as well in professional sports. And from this, we have a lot of anecdotal evidence, right? We have these stories from athletes about their personal experiences with float. I'm using float for mental recovery. That helps me visualize before a game what I need to do. I use float for muscle fatigue, muscle soreness. So these are really powerful, they're powerful marketing techniques as well, right? There's nothing better than a high-profile athlete saying, yes, float. But again, in order to make evidence-based recommendations, in order to move forward best practice. These float tanks are in place with these athletes. We want to make sure that they're using them in the best way. That we can give them advice about what's going to be most adaptive for them. So we have to study it. We have to study the underlying physiological mechanisms that float can mediate. All right, so one of the biggest claims in float research is that we can induce deep relaxation. And unlike maybe competing relaxing techniques, we can do so with very limited instruction, very little practice. Is this true? This is one of the first questions that I wanted to look at in my group of athletes. I wanted to characterize, what does this novice float experience look like? Do they find their first float experience relaxing? Because think of the context of this. It's in the training room. They're just hopping in, they're having a float. They hate it, they're probably not going to do it again. So what does this look like? How can this inform our own ability to tell them what to expect? And there are things that we can learn from this process. So we had 14 trained individuals come in for this study with no prior experience to floatation rest. I briefly showed them the float room, gave them a rundown of proper procedures. We'd assessed some psychometric assessments both before and after the float, as well as we did a blood draw to look at circulating stress hormones, cortisol, epinephrine and norepinephrine. Following their float experience and their post-metrics, they then sat down with me. We did a semi-structured interview because I wanted to find it a little more depth and a little bit more detail about what this experience looks like. All right, so here's what we found. You're looking at the psychometric results here. Subscales from these questionnaires along the y-axis, change scores along the x. These have been grouped according to the direction of positive change. So those subscales that you're seeing in green, an increase would be considered a positive benefit, right? An increase in energy, an increase in positive affect. And then those red subscales would be what we consider positive change for a decrease over their float experience. So right off the bat, you're looking at this and you can see, hey, all subscales moved in positive direction. Furthermore, we saw statistically significant modification of these profiles in yellow with strong effect sizes for total mood disturbance, tension, and negative affect. Furthermore, these positive psychometric data points were accompanied by moderate reductions in circulating stress hormones. This is on their first visit. We saw this relates to a 12% reduction in norepinephrine, 25% reduction in epinephrine and 28% reduction in cortisol. But really exciting to me was what happened in the post-float interview. This gave me more actionable data. The first thing I asked them was to tell me, to describe in your own words, what was the float experience like? And it became very clear that they had this initial acclimation, and three experiences repeatedly came up. The first was trying to find a comfortable position for the arms and the neck. Trying to stay centered and avoid that ping-pong kind of effect, and adjusting to this complete level of darkness. I think they were really surprised by how dark it was in there. In addition to these overt physical symptoms, we also saw psychological acclimation. 36% of participants expressed some level of apprehension after entering the tank. They used words like feeling jittery, on edge, tense, or anxious. Even though we saw those positive changes, this is how they felt when they first got into the tank. The amount of time that it took to kind of become at ease in this environment varied by participant. A few expressed feeling at ease within maybe five minutes, but the majority expressed a longer duration on the order of 10 to 15 minutes. So 10 to 15 minutes into this first float, and they're still not loving it. I hope they stay in. Next I asked them about their intake experience, how they passed the time. And it became aware that naturally they increased their intercept of awareness. They were...multiple people made comments about hearing a heartbeat, listening and focusing on their breathing rate, and kind of identifying these changes in muscle sensations. Okay, I swear I didn't tell them just to think about it. They did that on their own. How they passed their time thought-wise. This was really diverse. Some people said it was a really thought-provoking experience, and suggested that they had these contemplative periods within the tank. Others said their mind was wandering, they couldn't think of a single concrete train of thought, and others expressed the absence of thought altogether. When asked about whether they slept in the tank, 40% of participants said they were awake the entire hour, 27% said they slept some degree, and 33% said they were unsure. I really relate to that unsure because I feel like I have that experience in the tank all the time, but the interesting piece to me was this one. The individuals that fell asleep but woke up before the session was over often had a negative experience after they woke up because they were focused on how much time is left. I have no idea how much time is left. How much time have I been in here? And is that constructive? Should we keep someone in a tank when maybe they're increasing their level of stress? Just something to think about. As far as problems, the typical ones. Three people got salt in their eye, and two people had problems with the seal on their earplugs. Physically, they commented about feeling looser, not as tensed, more relaxed. Two people commented on some reductions in baseline lower back pain, and two commented on feelings of improvement in muscle soreness. This was without exercise. This was just their baseline levels. Mentally, they described it as relaxing, calming, restorative. One person actually compared it to previous use of meditation. Said that the environment was less distracting, and they were able to stay kind of in this trance-like state for longer. And last but not least, upon exiting the tank, they said, overall, that they felt more alert and more energized. Now, whether this was a result of the tank or their experience with me, we'll never know. But overall, it seemed to be a very positive experience. To end this visit, I asked them to describe their first float using three words, and these are what they said. Nine out of 14 participants used the word relaxing. Overall, pretty positive words. The one negative, if you could call it that, might be underwhelming. But that's actually my favorite, because what do I want a stress reduction technique to be, calming and underwhelming? Of these 14 participants, everyone said that they would float again. After a single 60-minute float session, novice floaters demonstrated significant improvement in stress-related symptomology. They had an overall positive experience. However, there were these initial feelings of discomfort, and I think that's really important for us to remember. Both in setting up how we portray float to new people coming in, encouraging them to have a second experience. And then for those of us in the world of research who want to investigate acute interventions, I think we need to build in some familiarization. We need to make sure that we're not making claims on the inability to reduce relaxation when they're not even getting relaxed in the tank. Maybe they need one or two exposures before we attest this acute situation. All right, moving on. To actually look at the use of float in recovery from exercise stress. We wanted to look at whether a one-hour floatation rest session administered immediately after high-intensity resistance exercise would improve recovery processes and healthy resistance-trained males during the first 48 hours of recovery. We recruited 12 participants for this, 18 to 35 years old. They had to actively incorporate a resistance training periodized program. We chose this because it kind of spans the gamut of a lot of sporting contexts. Most athletes are using resistance training to improve both power and strength in their normal programs. And to indicate that they were trained, they had to be able to squat with proper form at least one and a half times their body weight. Okay, you're looking at their subject characteristics. Their strength to weight ratio is actually 1.8. So this equates to about 180 pound male squatting 330 pounds. Okay, they were trained. You can rest assured, these were trained individuals. They came into the lab for eight visits. The first two visits were for familiarization, right? I wanted them to get two one-hour exposures to float prior to initiating testing. They also got to be familiarized with the rest of the testing techniques that we would use. And then they completed two exercise testing blocks. The blocks were identical except for the use of recovery in each of these interventions. So in one testing block, they came in, did an acute resistance exercise stress, recovered with float, and then they came in 24 and 48 hours later and we looked at recovery. Then they had a two-week washout and when they came back, they used the control condition. We counterbalanced the order so that some were starting with float and some were starting with control. But each individual experienced both. We're not comparing two different groups of people. We're comparing the same people and their responses to these two different conditions. We also had a number of design controls. Participant times, they came in at 6 AM. We always started at 6 AM after an overnight fast. They were fasted for the entire visit. They had to refrain from exercise for 72 hours before coming in because we wanted to make sure that they were recovered when they started this. We checked their hydration. We made them fill out a three-day diet record during this first testing block. And then they had to replicate that, both what they ate, when they ate it during the second block. So physiologically, we were trying to make sure they looked as similar as we can. So we can really draw conclusions about whether any of these changes in recovery are due to this intervention. All right, what was this stress protocol? We used a 6 by 10 back squat with two minutes rest starting weight set at 80% of one RM. This is tough. Look at his face. This is probably set one, a very grueling exercise protocol. If spotter assistance was required, we'd reduce the weight by 10% for the next set. But they're doing six sets, ten repetitions each. After exercise, they either went into one of their control conditions. Same amount of time, one hour. Both considered passive, relaxing recovery conditions. And one, they're sitting in a reclining chair with their leg rest engaged, watching a nature documentary, undergoing continuous auditory and visual stimulation in contrast to our float, where we're seeing this reduced sensory environment. We assessed a number of stress recovery domains. Metabolic stress, neuroendocrine signaling, inflammation, structural damage, muscular performance, perception of mood state, fatigue, soreness. We assessed all these things at five time points. Before exercise, immediately after this intense exercise, immediately after their one hour recovery, and then 24 and 48 hours later. The stress worked. All right, what you're looking at here is post exercise in both testing blocks. We had metabolic, adrenergic, and mechanical stress. Very evident, even in these trained individuals. Lactate response up 12.9 fold. Circulated catecholamines, 9.7, 7.2 fold increases. And the mechanical stress, outrageous. The volume load, which is calculated as the number of unassisted repetitions times the mass of the barbell, nearly 6,000 kilograms. That's how much stress they were under during this short six by ten protocol. Okay, what did we find in recovery? In terms of blood lactate response, nothing. In both the control and the float condition, participants were able to recover lactate response within that one hour. Now, this is a common marker in recovery studies. And for trained individuals, I really don't think it's that worthwhile. Trained individuals are able to pretty much recover metabolically in a very short amount of time. So should we be surprised that we're not seeing any changes? Probably not. They're both passive recovery and they're recovering. In fact, while it looks like IR here, post recovery, there's a little bit of elevation significantly. We consider resting lactate between one and two millimoles. So they're absolutely recovered in both conditions. We actually saw the same thing with cortisol. It peaked during exercise, it recovered in both conditions. We were surprised by this one because we've seen cortisol time and time again be reduced with float. But in this situation, the intense negative feedback system in trained athletes, after an initiation of a cortisol response, is to turn off the signaling. So we saw a reduction in both groups. We did see a significant treatment effect for circulating norepinephrine, while both groups had a pretty marked recovery over this one hour recovery block. They did recover to a greater degree with float than they did in the control condition. We also saw some changes in testosterone signaling at this post-recovery time point. The temporal time pattern pretty much the same, but immediately post-recovery. Testosterone was slightly elevated in the float group. Now, we're talking a difference of one nanomole. Is that significant? We'll find out. But testosterone is a very, very potent anabolic signaling marker. And so the potential for it to affect protein synthesis and changes in strength are pretty important. So we wanna investigate this more. In terms of inflammation, we saw no change. In terms of structural damage, we saw no change. In both cases, participants responded similarly. Was there damage? Absolutely. Look at that peak myoglobin at that one hour time point, elevations in creatine kinase at 24 and 48 hours. It did not change. Without seeing changes in this catabolic signaling, inflammatory signaling, damaged signaling, probably shouldn't be that surprised that we didn't see changes in performance, right? In both the float and the control condition, performance decreased in squat and counter movement jump most drastically immediately after exercise, but it was still decreased at 24 and 48 hours into recovery. Where we did see major changes were in perceptual markers. Float mediated the soreness response. At every time point, one hour, 24 and 48 hours, perceived soreness was significantly less than it was in the control group. Now keep in mind their damage was the same. They experienced the same structural damage, but they felt better. In terms of pain, we didn't see an effect. Intensity of pain, no change between the float and the control. Where we did see differences, however, were in these sensory pain characteristics. So I know this is a lot on the slide, so I'm gonna try to direct you towards this. What you're looking at here are individual pain characteristics, and when participants are filling out this survey, they're marking, did I feel like my pain was heavy? Was it tender? Was it aching? So you're looking at the percentage of participants that rated each of these characteristics. Immediately post exercise, they're similar. Thank God, we did our job right, right? We induced the same level of damage in our stress model. After recovery, we see a little bit of difference. Look at the length of that gray bar in comparison to the blue. Control group experienced heavier and more aching pain sensations following their recovery with control than they did with float. At this 24 hour mark, some participants, we're on talking about two or three participants here, had much more severe pain characteristics following the control than they did with float. We see evidence of sharpness, splitting, shooting, stabbing. Okay, yeah, I don't wanna feel those things. But then at 48 hours, they looked similar again. In terms of mood state and fatigue, we again saw some positive mediation with float. What you're looking at here is the difference between post exercise level and the post recovery. So over that one hour recovery treatment, whether that be the control in gray or the float with blue, how much change we saw in these scores. Significant changes for float in negative affect, total mood disturbance, and fatigue, right? Effect size is greater than one. However, we didn't see this same thing at 24 and 48 hours. At 24 and 48 hours, they looked the same. So take away message here. A 60 minute float immediately following intense muscle damaging exercise, improved muscle soreness, improved mood state, and improved fatigue and resistance trained men, particularly immediately post treatment. We saw some modifications of neuroendocrine signaling pathways, both for testosterone and norepinephrine. We did not see any changes in structural damage or inflammation. Okay, this sounds negative, I know. However, this may actually suggest the suitability of float for more chronic treatment, especially for managing pain, soreness, and fatigue. Why is that? One of the criticisms of acute interventions is reduction in the typical damage and rebuilding profile of skeletal muscle. If we stop the signaling, we impair strength gains as well. And we've seen this in the literature with cold immersion therapy. Actually, some reduction in strength when cold immersion therapy is used chronically. And we still recommend it when you have a performance right away and you want you to feel better. Yes, but maybe you're not gonna use that during your phases when you're not in competition, right? So we need to investigate this a little bit more, but this suggests maybe the suitability of float in management throughout the training and competitive season. I may be at the end of my talk, but we're just at the beginning here. I have more questions than I have answers. Things that I'm curious about. What happens when float is delivered at a different stage in the recovery process? So we chose to deliver float immediately after exercise because we wanted to look at both these short-term recovery, which typically are those metabolic factors, some of that stress signaling, as well as what happened later in the recovery paradigm. But what if we deliver float at 24 or 48 hours? When we already have established soreness, when we already have established markers of damage, is it gonna look different? Are they gonna feel different? If I give it to them at 24 hours, are they gonna be able to maintain it and feel better at 48? I don't know, we'll find out. What happens with a more chronic exposure? Keep in mind, in this study, they had only floated three times ever. Is that playing a role in our ability to mediate recovery? How does float affect a recovery domains with a different exercise paradigm, potentially one with a lot less underlying muscle damage? This was a very muscle damaging induced study. So that's not typical of every sporting environment. Might we see performance changes? Might we see different mediation if we use a different, maybe more sport relevant design? And how about symptoms of chronic stress? I think it was very clear that the trained individuals in this study were healthy. They demonstrated really healthy patterns of hormone signaling. But in chronic stress, we get all kinds of crazy things. Extended elevation. Is float gonna be able to mediate some of these errant signaling pathways? Possibly. I am just setting up my lab at the University of North Texas and I'm very excited about continuing this line of research. So this is not the last you'll hear from me. I wanna know the answers to these questions and I wanna leave you with this. This year more than ever, we've seen the importance of mental health and athletics. It's taken center stage, right? We've seen how it affects performance. We have to manage this. We are not doing our athletes any service by continuing to ignore it. And I think that stress reducing modifications, giving athletes the ability to cope and handle their environment better. Whether you're changing their level of soreness or not, do they feel better? Do they feel better able to tackle their day? I think that float has a real possibility in this context as well. Thank you guys.