THE ACUTE EFFECTS OF FLOTATION RESTRICTED ENVIRONMENTAL STIMULATION TECHNIQUE ON RECOVERY FROM MAXIMAL ECCENTRIC EXERCISE PAUL M. MORGAN,AMANDA J. SALACINSKI, AND MATTHEW A. STULTS-KOLEHMAINEN Department of Kinesiology and Physical Education, Northern Illinois University, DeKalb, Illinois 07/25/2018 on BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD33gDmupaxCIysA/NcnDS8yusdAPJCMvL8fp/9fSP5jhUVFT+i+Di9ow== by https://journals.lww.com/nsca-jscr from Downloaded ABSTRACT athletes to help reduce blood lactate levels after eccentric Downloaded Morgan, PM, Salacinski, AJ, and Stults-Kolehmainen, MA. The exercise. acute effects of flotation restricted environmental stimulation KEY WORDS from Epsom salt, lactate, knee extension, muscle https://journals.lww.com/nsca-jscr technique on recovery from maximal eccentric exercise. strength J Strength Cond Res 27(12): 3467–3474, 2013—Flotation restricted environmental stimulation technique (REST) involves INTRODUCTION compromising senses of sound, sight, and touch by creating o maximize overall performance, an athlete must a quiet dark environment. The individual lies supine in a tank focus on both training and recovery. However, this by BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD33gDmupaxCIysA/NcnDS8yusdAPJCMvL8fp/9fSP5jhUVFT+i+Di9ow== of Epsom salt and water heated to roughly skin temperature period of rest after a training session is frequently (34–358 C). This study was performed to determine if a 1-hour T overlooked, and over time, this may lead to over- flotation REST session would aid in the recovery process after training and underperformance. During immediate recovery maximal eccentric knee extensions and flexions. Twenty-four from intense bouts of exercise, the body often experiences untrained male students (23.29 6 2.1 years, 184.17 6 6.85 acute muscle soreness because of acidic conditions of the cm, 85.16 6 11.54 kg) participated in a randomized, repeated blood, or lowering of the blood’s pH, that stems from an measures crossover study. The participants completed 2 exer- accumulation of lactic acid, lactate, or H+ (2,5,14). To com- cise and recovery protocols: a 1-hour flotation REST session bat this increase and the decrement in performance after and a 1-hour seated control (passive recovery). After isometric exercise, individuals often partake in 1 or more recovery muscle strength testing, participants were fatigued with eccen- techniques. Over the past decade, many recovery methods tric isokinetic muscle contractions (50 repetitions at 608$s21) have been systemically investigated, including massage, of the nondominant knee extensors and flexors. Blood lactate, cryotherapy, contrast water immersion therapy, active recovery, compression garments, and sleep (3). Several of blood glucose, heart rate, OMNI-rating of perceived exertion these methods are associated with enhanced postexercise for resistance exercise (OMNI-RPE), perceived pain, muscle muscular recovery and performance along with a concomi- soreness, and isometric strength were collected before exer- tant reduction in blood lactate (1,9,15,19,23,38). Each of cise, after treatment, and 24 and 48 hours later. A multivariate these methods have limitations, such as risk of further tissue analysis of covariance found that treatment had a significant damage with massage, potentially extreme discomfort from main effect on blood lactate, whereas subsequent univariate cryotherapy or contrast water immersion, or the expense of analyses of variance found statistical significance with the numerous compression garments. Furthermore, all these immediate posttreatment blood lactate measures. The results techniques have a small effect size. indicate that flotation REST appears to have a significant However, a relatively unexplored method of recovery, impact on blood lactate and perceived pain compared with a flotation restricted environmental stimulation technique on 07/25/2018 1-hour passive recovery session in untrained healthy men. No (REST), may have a greater effect size and fewer limitations. difference was found between conditions for muscle strength, Flotation REST involves reduction of environmental stimuli blood glucose, muscle soreness, heart rate, or OMNI-RPE. so that the human senses of sight, sound, and touch are Flotation REST may be used for recreational and professional compromised. The use of flotation has been in use since its invention in 1977 by John C. Lilly, in which the participant Address correspondence to Paul M. Morgan, PaulMinWooKimMorgan@ floated in a warm water and Epsom salt solution (33). The gmail.com. individual floats supine in an enclosed or open vinyl-lined 27(12)/3467–3474 tank with no light and water heated to roughly skin temper- 8 Journal of Strength and Conditioning Research ature (34–35 C) by a waterbed heating system. Participants Ó 2013 National Strength and Conditioning Association float with arms to their side to mitigate the sensation of VOLUME 27 | NUMBER 12 | DECEMBER 2013 | 3467 Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited. Effects of Flotation REST on Recovery touch via their hands against their body and the surrounding after the treatments to determine the effect of either the environment (13,35). The tanks are not airtight and are filled seated control or the flotation REST treatments. To gauge with roughly 757.08 L of water mixed with 362.87 kg of metabolic strain and recovery from the muscle damaging Epsom salt so that the individual is capable of floating. protocol, glucose and lactate were measured. Furthermore, The water is filled with Epsom salt (magnesium sulfate, high accumulation of lactate is associated with muscle MgSO4) to a concentration (1.81 kg:3.79 L) considerably fatigue (2). Therefore, decreases in the amount of lactate higher than that of the Dead Sea, allowing for effortless may be indicative of better recovery and better performance flotation in a solution that does not cause skin irritation (12). as previous research has observed improvements in resis- Flotation REST has been used for a variety of ailments tance exercise performance associated with lower lactate that include chronic pain (16), anxiety (16), and hyperten- levels (1,9). OMNI-rating of perceived exertion for resistance sion (13,18,34). It has also been used as a stress management exercise (OMNI-RPE) (28), perceived pain scale (8), and medium to lower blood pressure, heart rate, and increase a 100-mm Visual Analog Scale (VAS) to measure DOMS muscle relaxation for an overall sense of better well being were used to determine the effect the treatments had on (11). However, no studies, to the current knowledge of the the individual’s perceptions of effort and soreness. researchers, regarding flotation REST and recovery from Subjects intense exercise have been performed. This is important Participants completed a detailed medical health history because flotation REST has previously shown decrements form to screen for any health issues that may prevent them in heart rate (11), blood pressure (13,18,34), and lactate from safely partaking in the study. Twenty-four healthy men (31). Therefore, the purpose of this study was to determine (23.29 6 2.1 years, 184.17 6 6.85 cm, 85.16 6 11.54 kg) from the effects of flotation REST on the recovery from an acute a large Midwestern University participated in this study. Par- bout of strenuous eccentric knee extensions and flexions ticipants were explained all procedures and were given time compared with a seated passive recovery. It was hypothe- to ask questions regarding the study. Participants were col- sized that there would be a reduction in blood lactate, heart lege-aged students who were screened for exercise habits rate, perceived exertion, and perceived pain with enhanced and deemed untrained if they performed resistance exercises recovery of knee extensor and flexor isometric strength with less than 3 d$wk21 (17). Men who had a body mass index greater alleviation of delayed onset muscle soreness (BMI) greater than 29.9 were excluded as those with a BMI (DOMS) after a 1-hour session of flotation REST compared of 30 and higher are categorized as obese and are at a signif- with a passive recovery period. icantly greater risk of cardiovascular disease, hypertension, METHODS poor cholesterol ratio, and mortality (10). Individuals were also excluded if they have had recent surgery, a history of Experimental Approach to the Problem any knee pathologies (i.e., ligament tears), or medical condi- To investigate the effects of RESTon recovery, a randomized tion in regards to the knee (i.e., chronic hyperextension of crossover design was used where each participant acted as the knee, surgical alteration, or injury). Individuals who had their own control. For the purposes of this study, we a history of claustrophobia were also unable to participate intended to use healthy normal population individuals before because of the conditions of the experimental environment. including a specialized population of either unhealthy or Participants provided written informed consent after reading athletic populations. These untrained men were asked to an informed consent document and having all questions participate to determine if the experimental protocol will answered regarding the study. This study was approved by show a change in the normal population before testing the institutional review board. a specialized population (i.e., athletes). Women were not included in this study because of the