Our objective was to assess the effects of consuming electrokinetically modified water (EMW) on fatigue attenuation and ratings of perceived exertion (RPE) following resistance exercise. A double-blind, placebo-controlled, two-arm trial was used in this investigation. Forty participants were randomly assigned to either an experimental or a placebo-control group. Participants consumed the EMW or placebo water daily for eighteen days prior to completing a fatigue protocol for the elbow flexors. The fatigue protocol consisted of a single bout of resistance exercise for the biceps brachii. Participants were tested for isometric strength before exercise and immediately following exercise. The maximal voluntary isometric contraction was used as the criterion measure for strength. To calculate the fatigue index, the postexercise maximal voluntary isometric contraction value was divided by the preexercise maximal voluntary isometric contraction value multiplied by 100. Also, ratings of perceived exertion (RPE) were assessed using the Borg scale. Fatigue indices and RPE were significantly lower for the experimental group compared to the control group (
Muscle fatigue during and after a single bout of high intensity exercise impairs physical performance and may increase the risk for musculoskeletal injury [
RNS60 was shown experimentally to display direct cytoprotective and anti-inflammatory treatment effects through activation of the type IA phosphatidylinositol-3 (PI-3) kinase/Akt pathway and inhibition of NF-
A technology similar to that used to produce RNS60 was used to make a beverage suitable for human consumption and has led to the development of electrokinetically modified water (EMW). EMW is manufactured from reverse osmosis water with an added mineral content of calcium chloride, magnesium chloride, and potassium bicarbonate and an elevated oxygen concentration. No other chemicals are added. EMW is manufactured in a similar manner to RNS60. While its potential effects on intracellular signaling pathways affected by RNS60 have not been directly examined, recent evidence has shown that oral consumption of the EMW positively influenced training adaptations in humans undergoing a treadmill exercise regimen [
Based on the early performance test results in humans showing positive effects on muscle function and cytoprotection as a result of consuming EMW [
Forty healthy, physically active males and females volunteered to participate in the trial. Participant demographics and descriptive statistics are listed in Table
Participant characteristics for the EMW and PLA groups.
Gender | Age (years) | Height (cm) | Weight (kg) | BMI | |
---|---|---|---|---|---|
EMW | 10 men, 10 women | 23.1 ± 3.0 | 170.0 ± 9.3 | 72.5 ± 13.8 | 24.6 ± 3.0 |
PLA | 9 men, 11 women | 24.0 ± 4.3 | 174.8 ± 8.2 | 72.5 ± 13.2 | 23.6 ± 3.2 |
Values listed as mean ± SD; EMW: electrokinetically modified water; PLA: placebo water.
A double-blind, placebo-controlled, two-arm trial was used in this investigation. Participants were randomly assigned to either experimental (
Flow chart demonstrating the time line for the experimental protocol. IFC-informed consent.
The electrokinetically modified water (EMW) was manufactured from reverse osmosis water with an added mineral content of 1.84 mg/L calcium chloride, 1.84 mg/mL magnesium chloride, and 1.17 mg/mL potassium bicarbonate and oxygen at a final concentration of ≥45 ppm by processing in a rotor/stator device at 4°C (patent #6,386,751). Placebo-control water was made from the same source water by adding the same minerals without processing in the rotor/stator device. The EMW and placebo-control water were packaged in identical 500 mL plastic bottles, and participants were instructed to consume a daily prescribed dose of the beverage (EMW or placebo) based on body weight categories: <59.1 kg = 2, bottles/day (b/d); 59.1–72.7 kg = 3 b/d; 72.7–86.4 kg = 4 b/d; 86.4–100 kg = 5 b/d; >100 kg = 6 b/d.
The fatigue protocol consisted of a single bout of resistance exercise for the biceps brachii muscle. An isokinetic testing and exercise device (Kin-Com 125 AP, Isokinetic International, Chattanooga, TN, USA) provided resistance during arm exercise. Prior to the fatigue protocol each participant completed a series of stretching exercises involving all of the major muscle groups of the upper extremity. Participants were then seated in the Kin-Com with their dominant arm secured at their side in 90° elbow flexion. Initially, the participant’s maximal voluntary isometric contraction (MVC) was measured (N-m) and then the subject began the exercise protocol. The fatigue protocol required participants to perform repeated maximal shortening (concentric) and lengthening (eccentric) actions for the biceps brachii muscle group. The angular velocity was set at 45°/sec for concentric actions and 60°/sec for eccentric actions. Each participant completed 3 sets of 20 repetitions and was instructed to perform the arm repetitions “as hard as they can.” Participants were given a 1-minute recovery period between sets. Verbal encouragement was provided by the investigator during the fatigue protocol.
Maximal voluntary isometric contraction (MVC) was assessed using the Kin-Com dynamometer. The MVC is the peak isometric torque produced during a static muscle contraction and was used as the criterion measure for isometric strength. Participants were seated with their dominant arm placed at their side in 90° elbow flexion. Each participant performed three maximal voluntary isometric contractions of the dominant arm. Each contraction was held for five seconds. A 30-second recovery period was provided between contractions. The most forceful contraction of the three values was recorded as peak torque in N-m. The MVC was measured before exercise (baseline) and again immediately following the fatigue protocol and the scores were used to calculate the fatigue index. The fatigue index (FI) is the percent decline in MVC from beginning to the end of the exercise fatigue protocol and was calculated for each participant by subtracting the postexercise MVC value from the preexercise MVC value and then dividing the difference score by the preexercise MVC value multiplied by 100.
Ratings of perceived exertion (RPE) were measured using the Borg scale [
Descriptive data generated for each outcome variable was reported as mean ± SD. Fatigue indices and RPE scores were analyzed using independent (unpaired)
Table
The experimental group had a smaller decrease in MVC (N-m) from preexercise to immediately postexercise compared to the control group (Table
Maximal voluntary contraction (N-m) values for the EMW and PLA groups.
EMW | PLA | |
---|---|---|
Preexercise | 38.5 ± 19.0 | 46.5 ± 26.0 |
Postexercise | 19.1 ± 10.0 | 22.4 ± 14.0 |
Values listed as mean ± SD; EMW: electrokinetically modified water; PLA: placebo water.
The fatigue index (%) was significantly lower for the experimental group compared to the control group indicating that the group that consumed the EMW displayed less strength loss pre- to postexercise (
Fatigue indices show that participants who consumed unprocessed water (PLA) lost significantly more isometric strength as a result of the exercise protocol than participants who consumed the EMW (
Ratings of perceived exertion scores indicated that the fatigue protocol was perceived as less effortful by the experimental group than by the control group (
Participants who consumed unprocessed water (PLA) reported significantly higher ratings of perceived exertion immediately after the exercise protocol than participants who consumed the EMW (
Our findings demonstrate that oral consumption of an electrokinetically modified water (EMW) beverage can improve skeletal muscle function. Consuming the EMW 18 days prior to high intensity resistance exercise attenuated muscular fatigue and subjectively made the strenuous resistance exercise feel less taxing.
In the present study, the group that consumed unprocessed water was found to have a 20% greater absolute loss of isometric strength after the arm resistance exercise protocol compared to the group that consumed the EMW. The preexercise to postexercise differences in strength loss indicate that the group who consumed EMW experienced less muscle fatigue during the exercise protocol when compared to the placebo-control group. Fatigue and strength loss during protracted muscle activity have been postulated to increase the risk of strain injury. Garrett et al. [
Our finding of attenuated strength loss in subjects who consumed EMW was paralleled by lower session RPE assessed using the Borg scale. RPE is a subjective means to measure fatigue and is used extensively in human performance research laboratories as well as in clinical practice settings to subjectively gauge the level of stress and perceived exertion an individual is experiencing during strenuous exercise [
The perception of physical exertion during voluntary muscle work comes from multiple sensory inputs originating in muscle and joint structures that are under mechanical, chemical, and thermal stress [
While the exact mechanism of action by which the EMW attenuates strength loss and perceived exertion is unclear, we speculate that exercise-induced muscle fatigue is mitigated by EMW consumption through a reduction of sarcolemma disruption or reduced impairment on neuromuscular function. In humans, the EMW has shown functional and cytoprotective [
We recently reported that subjects who consumed the EMW for 18 days prior to completing a single bout of high intensity eccentric exercise had significant reductions in the extent of muscle damage and postexercise inflammation compared to subjects who consumed unprocessed water [
Reducing the extent of strength loss during prolonged exercise is important for athletes involved in training and competition by sustaining their work capacity and lessening their risk for musculoskeletal injury. Oral consumption of the EMW is a novelty for athletes and physically active individuals alike in that the beverage can be consumed not only as an aid to maintain hydration levels, but additionally with the intent of attenuating strength loss as a result of intense resistance exercise. Thus, the combined fluid replacement/hydration and functional improvements of consuming EMW can benefit these individuals by moderating the physiological and psychological stress of intense exercise training and competition.
From a dose-response perspective evidence shows that positive ergogenic and protective effects occur when pre-fatigue and exercise consumption periods are between 14 and 18 days [
Study limitations include the use of only one dosing schedule for subjects and the use of a small muscle mass for testing (biceps brachii). Also, the study participants were physically active; however, they were not considered to be elite or highly trained competitive athletes, thus limiting the generalizability of the results. The generalizability of the research findings could be increased by examining the possibility of a differential sex effect of EMW consumption. More research is necessary to substantiate our findings and to delineate the molecular events involved. Our study suggests a novel application for the EMW and reproducing the positive results of this study and the one by Cooper at al. [
Oral consumption of EMW for 18 days prior to high intensity resistance exercise can significantly reduce muscular fatigue and RPE during strenuous exercise. The combined effects of fatigue attenuation and lower RPE may decrease the risk for musculoskeletal injury as well as enhance postexercise recovery mechanisms.
The authors declare that there is no conflict of interests regarding the publication of this paper.
The study was supported by the Revalesio Corporation (Tacoma, WA, USA). The authors would like to thank Dr. Andreas Kalmes for help with editing. The results of the current study do not constitute endorsement of the product by the authors or the journal.