Negative ion technology is also hypothesized to have positive physiological effects that could improve various aspects of human performance. Negative ions are negatively charged naturally occurring particles in the air. These ions are formed when energy from the shearing of water droplets in waterfalls or rain, radiation, or lightening acts on air molecules such as carbon dioxide, oxygen, nitrogen, or water and ejects on their electrons creating a positively charged ion (13). The free electron then attaches itself to a nearby molecule, thus forming a negatively charged ion. The concentration of naturally existing negative ions depends on the environment. The ion concentration in fresh country air is approximately 3,000 negative ions per cubic centimeter, whereas the concentration in large urban cities is less than 100 negative ions per cubic centimeter. These negatively charged ions, especially negative oxygen ions, have positive health benefits including: protect the body from harmful pollutants in the air, induce relaxation, increase alertness, and strengthen immune system, etc. (7,17).
As stated previously, negative ion technology is also hypothesized to have positive physiological effects that could improve various aspects of human performance. However, there is a scarcity of controlled research supporting the claims of various manufacturers of performance jewelry embedded with negative ions. The proposed mechanism of action for these ions is the activation of superoxide dismutase (SOD), whose chief action is the suppression of the superoxide radical, which causes oxidative damage to various tissues (16). Kosenko et al. (16) reported that negative air ions stimulate the activity of SOD in erythrocytes from rats, ducks, and humans. A negative ion solution of saline and heparinized blood increased SOD activity by up to 200% in human erythrocytes after 60 minutes of exposure (21). A detailed description of those procedures is available here (16). Livanova et al. studied the effects of negative air ions on physiological functions under the conditions of prolonged chronic stress and acute immobilization stress in rats. The authors reported that there were no significant increases in the typical markers of respiratory stress (succinate dehydrogenase and NADH dehydrogenase), regardless of the rats' characteristic behavior type (17). Additionally, Livanova et al. reported that short-term exposure to negative air ions during immobilization can prevent episodes of acute stress. Ryushi et al. studied the effects of negative air ion exposure (8000–10,000 cm−3) during recovery after 1 hour of aerobic exercise at 50–60% of a subject's maximal oxygen uptake. The authors reported that diastolic blood pressure and serum level of dopamine and serotonin were significantly reduced during recovery in those exposed to the negative air ions (6). The drop in diastolic blood pressure is believed to be caused by vasodilation in the presence of negative air ions (17). Finally, Iwama et al. (13) provided evidence that negative ions created by the shearing of water molecules improve aerobic metabolism by improving erythrocyte deformability, decreasing blood lactate levels, and increasing venous blood pH levels. Protocol by Iwama et al. required subjects to recline in a supine position, and the team placed electric air purified humidifiers that create negative air ions through water shearing near the subjects. After exposure, the aforementioned lab results were recorded. These findings could be viewed as possible mechanisms for improved aerobic performance.
Within the last few years, various manufacturers have used negative ion technology to produced a variety of “performance enhancing” jewelery (9,12,19). These manufacturers have led massive advertising campaigns promoting their negative ion performance jewelry and have coincidentally created a “craze” within the fitness community (21). These advertising campaigns, and the resulting increase in demand for the product, have given life to claims of increased fitness performance as a result of wearing the jewelry. The majority of these claims are anecdotal, making it essential to constantly evaluate evidence to determine the validity of a product that has been placed on the market. One such performance jewelry manufacturer is EFX Performance, Inc. (Orange County, CA, USA) (9). The EFX performance jewelry pieces are embedded with a source of negative ions (8). Additionally, holograms that are composed of Mylar, a polyester film used for imprinting various media and data are also included in the bands.
Based on the aforementioned lack of research designed to evaluate the efficacy of performance jewelry and the breadth of anecdotal testimony supporting various benefits, this research study was conducted. This double-blind, randomized, controlled trial tested the hypothesis that the negative ion and hologram-embedded wristbands would have no impact on maximal oxygen uptake, oxygen consumption at ventilatory threshold, or the heart rate at ventilatory threshold (HRVT) in trained runners.
Experimental Approach to the Problem
Driven by the need for experimental research regarding performance enhancing jewelry, this research design was implemented. Three dependent variables were assessed; (a) mean V[Combining Dot Above]O2max, (b) V[Combining Dot Above]O2 at ventilatory threshold, and (c) heart rate at ventilatory threshold. One independent variable with 3 levels was addressed; (a) graded exercise test with a programmed bracelet, (b) graded exercise test with a nonprogrammed bracelet, and (c) a control-graded exercise test with a bracelet. This study was designed to use randomization and blinding of the subjects and those participating in data collection as to the conditions of the programmed or nonprogrammed status of the bracelets. Therefore, a repeated measures design was indicated and applied. The determination of V[Combining Dot Above]O2max through metabolic gas analysis is considered the gold stand for quantifying aerobic capacity and was used to collect the dependent variables during the study (2,4–6,10,11,15). V[Combining Dot Above]O2max (ml·kg−1·min−1) V[Combining Dot Above]O2VT, and HRVT served in this capacity and were recorded during maximal treadmill testing.
Eighteen individuals (age = 26.5 ± 7.18 years) comprising 8 males (44.4%) and 10 females (55.6%), volunteered to participate in this study approved by the Belmont University Institutional Review Board. Descriptive statistics pertaining to the subjects are present in Table 1. A verbal script describing the study was presented to members of a local running club, students of the Belmont University Physical Therapy Department, and local running contacts to recruit participants. Each participant completed a written informed consent, lower quarter screen (LQS), and health history questionnaire (HHQ) to determine eligibility before data collection. Inclusion criteria for participation included: (a) adults aged 18–50 years, (b) all resting vital signs within normal range as indicated by the American College of Sports Medicine (ACSM), (c) LQS showing no pathology, (d) answering “no” to all questions in the HHQ, and (e) run a minimum of 15 miles per week. Individuals were excluded from the study for the following reasons: (a) answering “yes” to any question on the HHQ, (b) failure of the LQS, and (c) any medical condition requiring clearance of a physician for strenuous activity without such written clearance.
The EFX silicone bracelet with hologram technology containing negative ions was used as the “programmed” device. An identical silicone bracelet that did not contain the negative ion or hologram technology was used as the “nonprogrammed” band. A third condition in which the participants did not wear a band served as a control trial. The status of the wristbands being worn during testing sessions were blinded from the participants and researchers and labeled by a third party. On initial testing session, each subject randomly drew the order in which they would be performing the 3 trials over the course of 3 weeks. Before each trial, resting blood pressure (BP) and resting heart rate (HR) were measured and recorded. After assessment of baseline vitals, each subject was informed of the procedure for the graded exercise test after the Bruce Protocol (5,18) and of the use of the Borg scale of Perceived Exertion (RPE) with a prepared script (3). After the explanation of the procedure, subjects were prepped, for ECG leads and electrodes were applied according to the Mason-likar 12 lead system (1). The output from the ECG was used to monitor and record HR throughout testing.
On completion of the aforementioned pretest procedure, the subject began the exercise test. During the execution of the test, metabolic gas exchange was measured with a Viasys VMAX encore 29C metabolic cart (VMAX) (22). The metabolic cart was calibrated according to the manufacturer's instructions (22). The achievement of V[Combining Dot Above]O2max (ml·kg−1·min−1) was based on the achievement of 2 of the following criteria: respiratory exchange ration >1.15, HR within 10 beats of age predicted maximum (220-age), or volitional fatigue (1,2). On attaining V[Combining Dot Above]O2max, all subjects completed an active cool down. All testing was conducted based on the guidelines established by the ACSM (1). All testing followed the general indications for stopping an exercise test outlined by the ACSM. (1).
All data were analyzed through SPSS/PASW Statistics (version 20.0; Somers, New York, NY, USA). Descriptive variables of the subjects were calculated as mean and SD. Descriptive statistics were used to verify that the data met assumptions for parametric statistical procedures (Table 2). A repeated measures analysis of variance procedure was used to determine the mean for the 3 trials. Paired samples t-test with a Bonferonni correction were used to determine which mean differences were significant (p ≤ 0.05) in the event of a significant omnibus F statistic. An additional 2-way ANOVA was calculated to assess the impact of gender as an independent variable.
There were no significant differences found across the 3 conditions for any of the dependent variables selected for analysis. During the first series of data collection, instrument failure led to the loss of data for 1 subject, therefore, there were 17 subjects in trial A and 18 subjects in all other trials. The results for the mean V[Combining Dot Above]O2max values under the 3 conditions are listed in Table 2. The observed level of significance for the V[Combining Dot Above]O2max values was an F value of 0.721, and sig. = 0.494. The results for the mean V[Combining Dot Above]O2VT and HRVT are presented in Table 2. Regarding the V[Combining Dot Above]O2VT, the calculated F statistic was F = 1.585 and sig. = 0.221, whereas the HRVT data (F = 0.464, sig. = 0.633) revealed no significant difference (p ≤ 0.05).
After completion of the a priori data analysis, and additional mixed 2-way ANOVA was calculated. The addition of gender as an independent variable yielded very similar results with 1 exception. In terms of V[Combining Dot Above]O2max, the males had a significantly (p = 0.048) higher aerobic capacity than the females when using this model. However, post-hoc paired samples t-test with a Bonferroni correction identified no significant differences in the V[Combining Dot Above]O2max between the males and females.
Although there are multiple claims of improved performance of a variety of physical factors associated with the use of holograms and/or negative ion programmed jewelry, this study does not provide evidence to support those claims. Small mean differences across the trials are duly noted but none of the differences were either statistically or clinically significant. Making comparisons to similar research with the current findings proves difficult based on the lack of well-designed research protocols in this area. The evaluation of HRVT and V[Combining Dot Above]O2VT in the control condition (not wearing a band) yielded lower values than either of the trials with a band, HRVT = 136.50, 135.00, and 130.41 and V[Combining Dot Above]O2VT = 30.04 (ml·kg−1·min−1), 30.76 (ml·kg−1·min−1), and 27.27 (ml·kg−1·min−1), respectively (programmed, nonprogrammed, and control). None of these differences were statistically significant. One might expect decreased values in these dependent variables when wearing the band if there was any physiological benefit.
One interesting finding was that no improvements were seen with either the placebo or the device. It might be expected that an improvement with either the device or the placebo (or both) would be seen given potential expectancy from the participants, who were aware that they were exposed to both the real and placebo wristbands. This lack of an effect may be due to the nature of the testing being objective, i.e., measuring V[Combining Dot Above]O2max through metabolic analysis rather than assessing the participant's subjective experience of running capacity while wearing the band or not wearing the band. This information could provide additional evidence that improvement in performance while using the device is based on an individual's perception rather than any measureable objective data.
There are additional variables that remain to be assessed to evaluate the efficacy of the bracelets that are not addressed with in this article. Additional dependent variables that could be analyzed include ventilation (L·min−1), the ventilatory equivalent (VE) for O2 and CO2 (VE/V[Combining Dot Above]O2, VE/V[Combining Dot Above]CO2), levels of blood lactate, and diastolic blood pressure being among those. Any parameter that could possibly be impacted by the proposed vasodilation and reduction in blood lactate as suggested by Iwama et al and Ryushi et al. (13,20) could serve as alternate options for analysis.
Because of some limitations, 1 cannot take a declarative stance on the efficacy of the jewelry tested. The measurement of maximal oxygen consumption is a time-consuming endeavor and studies often contain low numbers of subjects. However, it should be noted that multiple studies of this nature (metabolic gas analysis and maximal treadmill testing) can be found in the literature with the common trend of having a limited number of participants. Having stated that a recommendation for larger subject recruitment in subsequent studies needs to be stated.
The data currently available indicate that negative ion and holographic technology wristbands have no significant effect on the parameters of human endurance performance as measured within the protocol of this study. The aforementioned anecdotal testimonials cannot be supported with current amount of scientific evidence. The lack of quantitative support for the use of these devices does not preclude the coach or athlete in their use. As previously mentioned, the subjective aspect of use was not assessed. The potential for improved performance is multifaceted, thereby creating an opportunity of perceived improvement of performance.
1. ACSM's Guidelines for Exercise Testing and Prescription (8th ed.). Baltimore, MD: Lippincott Williams &Wilkins, 2010. pp. 116–122; 83, 429.
2. Astorino T, Robergs RA, Ghiasvand F, Marks D, Burns S. Incidence of the oxygen plateau at VO2max during exercise testing to volitional fatigue. J Exerc Physiol Online 2000. Available at: faculty.css.edu/tboone2/asep/Astorin1.doc
. Accessed April 12, 2012.
3. Borg G. Borg's Perceived Exertion and Pain Scales. Champaign, IL: Human Kinetics, 1998.
4. Bruce protocol treadmill test. Top end sports. 2011. Available at: http://www.topendsports.com/testing/tests/bruce.htm
. Accessed November 23, 2011.
5. “Bruce treadmill test.” Bruce treadmill VO2max test. BrianMac sports coach, January 1, 2012. Available at: http://www.brianmac.co.uk/bruce.htm
. Accessed March 17, 2012.
6. Cammen-van Zijp MHM, Ijsselstijn H, Takken T, Willemsen SP, Tibboel D, Stam HJ, Berg-Emons RJG. Exercise testing of pre-school children using the Bruce treadmill protocol: New reference values. Eur J Appl Physiol 108: 393–399, 2010.
7. English J. The positive health benefits of negative ions
. Nutr Rev Available at: http://www.nutritionreview.org/library/negative.ion.html
. Accessed April 9, 2012.
8. EFX Performance Inc; EFX performance. 2011. Available at: www.efxusa.com
. Accessed April 12, 2012.
9. EFX Performance Inc; EFX performance. 2011. Available at: http://www.efxusa.com/Testimonials.html
. Accessed April 13, 2012.
10. Fielding RA, Frontera WR, Hughes VA, Fisher EC, Evans WJ. The Reproducibility of the Bruce protocol exercise test for the determination of aerobic capacity in Older Women. Med Sci Sports Exerc 29: 1109–1113, 1997.
11. Froelicher VF, Brammell H, Davis G, Noguera I, Stewart A, Lancaster MC. A comparison of the Reproducibility and Physiologic Response to three maximal treadmill exercise protocols. Chest 65: 1974, 512–517. Available at: http://chestjournal.chestpubs.org/content/65/5/512
. Accessed April 14, 2012.
12. Ion bracelets and negative ion bracelets. LifestrengthTM. 2010–2011. Available at: www.Lifestrength.com/the-vitamin-you-wear
. Accessed April 12, 2012.
13. Iwama H. Negative air ions created by water shearing improve erythrocyte deformability and aerobic metabolism. Indoor Air 14: 293–297, 2004.
14. Jackson AS, Pollock ML. Practical assessment of body composition. Phys Sprt Med 13: 76–90, 1985.
15. Kaminsky L, Whaley M. Evaluation of a new standardized ramp protocol: the BSU/Bruce Ramp protocol. J Cardiopulm Rehabil 18: 1998, 438–444. Available at: http://cms.bsu.edu/Academics/CollegesandDepartments/CEPP/Research/CEPProgramResearch/-/media/WWW/DepartmentalContent/CEPP/PDFs/1KaminskyACSM2010.ashx
. Accessed November 23, 2011.
16. Kosenko EA, Kaminsky YuG, Stavrovskaya IG, Sirota TV, Kondrashova MN. The stimulatory effect of negative ions
and hydrogen peroxide on the activity of superoxide dismutase. Fed Eur Biomed Societies 410: 309–312, 1997.
17. Livanova LM, Levinsha IP, Nozdracheva LV, Elbakidze MG, Airapetyants MG. The Protective effects of negative air ions in acute stress in rats with different Typological Behavioral characteristics. Neurosci Behav Physiol 29: 393–395, 1999.
18. Paridon S, Alpert B, Yetman A, et al.. Clinical stress testing in the pediatric age group: a statement from the American Heart Association Council on Cardiovascular Disease in the Young, Committee on Atherosclerosis, Hypertension, and Obesity in Youth. Circulation 113: 2006, 1905–1920. Available at: http://circ.ahajournals.org/content/113/15/1905.full
. Accessed December 11, 2011.
19. Power Energy Balance Inc; Power Energy Balance. 2012. Available at: www.powerenergybalance.com
. Accessed April 12, 2012.
20. Ryushi T, Kita I, Sakurai T, Yasumatsu M, Isokawa M, Aihara Y, Hama K. The effect of exposure to negative air ions on the recovery of physiological responses after moderate endurance exercise. Int J Biometeorol 41: 132–136, 1998.
21. Shook RP, Blair SN. You asked for it: question authority. ACSM's Health Fitness J 15: 5–7, 2011.
22. Vmax Spectra Series. Program Documentation. Viasys Healthcare. SensorMedics Corporation. Available at: http://www.viasyshealthcare.com/vmax_forum/Manuals/Operators/VmaxSpectraOp.pdf
. Accessed April 12, 2012.