51
|
Physiological mechanisms determining eccrine sweat composition. Eur J Appl Physiol 2020; 120:719-752. [PMID: 32124007 PMCID: PMC7125257 DOI: 10.1007/s00421-020-04323-7] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/11/2020] [Indexed: 02/08/2023]
Abstract
Purpose The purpose of this paper is to review the physiological mechanisms determining eccrine sweat composition to assess the utility of sweat as a proxy for blood or as a potential biomarker of human health or nutritional/physiological status. Methods This narrative review includes the major sweat electrolytes (sodium, chloride, and potassium), other micronutrients (e.g., calcium, magnesium, iron, copper, zinc, vitamins), metabolites (e.g., glucose, lactate, ammonia, urea, bicarbonate, amino acids, ethanol), and other compounds (e.g., cytokines and cortisol). Results Ion membrane transport mechanisms for sodium and chloride are well established, but the mechanisms of secretion and/or reabsorption for most other sweat solutes are still equivocal. Correlations between sweat and blood have not been established for most constituents, with perhaps the exception of ethanol. With respect to sweat diagnostics, it is well accepted that elevated sweat sodium and chloride is a useful screening tool for cystic fibrosis. However, sweat electrolyte concentrations are not predictive of hydration status or sweating rate. Sweat metabolite concentrations are not a reliable biomarker for exercise intensity or other physiological stressors. To date, glucose, cytokine, and cortisol research is too limited to suggest that sweat is a useful surrogate for blood. Conclusion Final sweat composition is not only influenced by extracellular solute concentrations, but also mechanisms of secretion and/or reabsorption, sweat flow rate, byproducts of sweat gland metabolism, skin surface contamination, and sebum secretions, among other factors related to methodology. Future research that accounts for these confounding factors is needed to address the existing gaps in the literature. Electronic supplementary material The online version of this article (10.1007/s00421-020-04323-7) contains supplementary material, which is available to authorized users.
Collapse
|
52
|
The role of sampling in wearable sweat sensors. Talanta 2020; 212:120801. [PMID: 32113563 DOI: 10.1016/j.talanta.2020.120801] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/13/2020] [Accepted: 01/31/2020] [Indexed: 01/29/2023]
Abstract
Wearable sweat sensors demonstrate outstanding performance in non-invasive, real-time monitoring of vital biomarkers in sweat, which offer an opportunity for individuals to achieve dynamic monitoring their own physiology in molecular-level. As a key step in sweat analysis that impact the accuracy of results, frequently-used sweat sampling methods are introduced in this review, and the emphasis is sweat sampling in wearable sensors including absorbent materials, superhydrophobic/superhydrophilic surface, sweat guidance and epidermal microfluidic systems. In the end, we also propose the remaining challenges in the practical, large-scale application of wearable sweat sensors and provide personal prospects on the future development.
Collapse
|
53
|
Hidden dynamics of soccer leagues: The predictive 'power' of partial standings. PLoS One 2019; 14:e0225696. [PMID: 31851667 PMCID: PMC6919612 DOI: 10.1371/journal.pone.0225696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 11/11/2019] [Indexed: 11/20/2022] Open
Abstract
Objectives Soccer leagues reflect the partial standings of the teams involved after each round of competition. However, the ability of partial league standings to predict end-of-season position has largely been ignored. Here we analyze historical partial standings from English soccer to understand the mathematics underpinning league performance and evaluate the predictive ‘power’ of partial standings. Methods Match data (1995–2017) from the four senior English leagues was analyzed, together with random match scores generated for hypothetical leagues of equivalent size. For each season the partial standings were computed and Kendall’s normalized tau-distance and Spearman r-values determined. Best-fit power-law and logarithmic functions were applied to the respective tau-distance and Spearman curves, with the ‘goodness-of-fit’ assessed using the R2 value. The predictive ability of the partial standings was evaluated by computing the transition probabilities between the standings at rounds 10, 20 and 30 and the final end-of-season standings for the 22 seasons. The impact of reordering match fixtures was also evaluated. Results All four English leagues behaved similarly, irrespective of the teams involved, with the tau-distance conforming closely to a power law (R2>0.80) and the Spearman r-value obeying a logarithmic function (R2>0.87). The randomized leagues also conformed to a power-law, but had a different shape. In the English leagues, team position relative to end-of-season standing became ‘fixed’ much earlier in the season than was the case with the randomized leagues. In the Premier League, 76.9% of the variance in the final standings was explained by round-10, 87.0% by round-20, and 93.9% by round-30. Reordering of match fixtures appeared to alter the shape of the tau-distance curves. Conclusions All soccer leagues appear to conform to mathematical laws, which constrain the league standings as the season progresses. This means that partial standings can be used to predict end-of-season league position with reasonable accuracy.
Collapse
|
54
|
Reeder JT, Xue Y, Franklin D, Deng Y, Choi J, Prado O, Kim R, Liu C, Hanson J, Ciraldo J, Bandodkar AJ, Krishnan S, Johnson A, Patnaude E, Avila R, Huang Y, Rogers JA. Resettable skin interfaced microfluidic sweat collection devices with chemesthetic hydration feedback. Nat Commun 2019; 10:5513. [PMID: 31797921 PMCID: PMC6892844 DOI: 10.1038/s41467-019-13431-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 11/05/2019] [Indexed: 11/09/2022] Open
Abstract
Recently introduced classes of thin, soft, skin-mounted microfluidic systems offer powerful capabilities for continuous, real-time monitoring of total sweat loss, sweat rate and sweat biomarkers. Although these technologies operate without the cost, complexity, size, and weight associated with active components or power sources, rehydration events can render previous measurements irrelevant and detection of anomalous physiological events, such as high sweat loss, requires user engagement to observe colorimetric responses. Here we address these limitations through monolithic systems of pinch valves and suction pumps for purging of sweat as a reset mechanism to coincide with hydration events, microstructural optics for reversible readout of sweat loss, and effervescent pumps and chemesthetic agents for automated delivery of sensory warnings of excessive sweat loss. Human subject trials demonstrate the ability of these systems to alert users to the potential for dehydration via skin sensations initiated by sweat-triggered ejection of menthol and capsaicin.
Collapse
Affiliation(s)
- Jonathan T Reeder
- Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
| | - Yeguang Xue
- Department of Civil and Environmental Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Daniel Franklin
- Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
| | - Yujun Deng
- Department of Civil and Environmental Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Jungil Choi
- Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
- School of Mechanical Engineering, Kookmin University, Seoul, 02707, Republic of Korea
| | - Olivia Prado
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Robin Kim
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Claire Liu
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Justin Hanson
- Department of Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - John Ciraldo
- Micro/Nano Fabrication Facility, Northwestern University, Evanston, IL, 60208, USA
| | - Amay J Bandodkar
- Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
| | - Siddharth Krishnan
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Alexandra Johnson
- School of Mechanical Engineering, Kookmin University, Seoul, 02707, Republic of Korea
| | - Emily Patnaude
- School of Mechanical Engineering, Kookmin University, Seoul, 02707, Republic of Korea
| | - Raudel Avila
- Department of Civil and Environmental Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Yonggang Huang
- Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
- Department of Civil and Environmental Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
- Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - John A Rogers
- Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA.
- Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA.
- Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA.
- State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, 200240, Shanghai, China.
- Departments of Chemistry, Electrical Engineering, Computer Science, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA.
- Departments of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
| |
Collapse
|
55
|
Bigg JL, Gamble AS, Vermeulen TF, Bigg LM, Spriet LL. Sweat Loss and Fluid Intake of Female Varsity Ice Hockey Players During On-Ice Practices and Games. J Strength Cond Res 2019; 34:389-395. [DOI: 10.1519/jsc.0000000000003351] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
56
|
Impact of 3-day high and low dietary sodium intake on sodium status in response to exertional-heat stress: a double-blind randomized control trial. Eur J Appl Physiol 2019; 119:2105-2118. [PMID: 31377851 DOI: 10.1007/s00421-019-04199-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 07/26/2019] [Indexed: 01/06/2023]
Abstract
PURPOSE To determine the impact of altering dietary sodium intake for 3 days preceding exercise on sweat sodium concentration [Na+], and cardiovascular and thermoregulatory variables. METHODS Fifteen male endurance athletes (runners n = 8, cyclists n = 7) consumed a low (LNa, 15 mg kg-1 day-1) or high (HNa, 100 mg kg-1 day-1) sodium diet, or their usual free-living diet [UDiet, 46 (37-56) mg kg-1 day-1] for 3 days in a double-blind, randomized cross-over design, collecting excreted urine (UNa) and refraining from exercise. On day 4, they completed 2 h running at 55% [Formula: see text]O2max or cycling at 55% maximum aerobic power in Tamb 35 °C. Pre- and post-exercise blood samples were collected, and sweat from five sites using absorbent patches along the exercise protocol. RESULTS UNa on days 2-3 pre-exercise [mean (95% CI) LNa 16 (12-19) mg kg-1 day-1, UDiet 46 (37-56) mg kg-1 day-1, HNa 79 (72-85) mg kg-1 day-1; p < 0.001] and pre-exercise aldosterone [LNa 240 (193-286) mg kg-1 day-1, UDiet 170 (116-224) mg kg-1 day-1, HNa 141 (111-171) mg kg-1 day-1; p = 0.001] reflected sodium intake as expected. Pre-exercise total body water was greater following HNa compared to LNa (p < 0.05), but not UDiet. Estimated whole-body sweat [Na+] following UDiet was 10-11% higher than LNa and 10-12% lower than HNa (p < 0.001), and correlated with pre-exercise aldosterone (1st h r = - 0.568, 2nd h r = - 0.675; p < 0.01). Rectal temperature rose more quickly in LNa vs HNa (40-70 min; p < 0.05), but was similar at the conclusion of exercise, and no significant differences in heart rate or perceived exertion were observed. CONCLUSIONS Three day altered sodium intake influenced urinary sodium excretion and sweat [Na+], and the rise in rectal temperature, but had no effect on perceived exertion during moderate-intensity exercise in hot ambient conditions.
Collapse
|
57
|
Parrilla M, Guinovart T, Ferré J, Blondeau P, Andrade FJ. A Wearable Paper-Based Sweat Sensor for Human Perspiration Monitoring. Adv Healthc Mater 2019; 8:e1900342. [PMID: 31293084 DOI: 10.1002/adhm.201900342] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/27/2019] [Indexed: 11/10/2022]
Abstract
The fabrication and performance of a wearable paper-based chemiresistor for monitoring perspiration dynamics (sweat rate and sweat loss) are detailed. A novel approach is introduced to measure the amount of aqueous solution in the order of microliters delivered to the sensor by monitoring a linear change in resistance along a conducting paper. The wearable sensor is based on a single-walled carbon nanotubes and surfactant (sodium dodecylbenzenesulfonate) nanocomposite integrated within cellulose fibers of a conventional filter paper. The analytical performance and the sensing mechanism are presented. Monitoring sweat loss in the human body while exercising is demonstrated using the integration of a wireless reader and a user-friendly interface. By addressing the barriers of cost, simplicity, and the truly in situ demanding measurements, this unique wearable sensor is expected to serve in the future in many different applications involving the on-body detection of biofluids, such as a monitoring tool of dehydration levels for athletes as well as a tool for enhancing the sport performance by providing an accurate recovery of the hydration status in daily exercises.
Collapse
Affiliation(s)
- Marc Parrilla
- Departament de Química Analítica i Química OrgànicaUniversitat Rovira i Virgili (URV) C/Marcel·l. Domingo 1 43007 Tarragona Spain
| | - Tomàs Guinovart
- Departament de Química Analítica i Química OrgànicaUniversitat Rovira i Virgili (URV) C/Marcel·l. Domingo 1 43007 Tarragona Spain
| | - Jordi Ferré
- Departament de Química Analítica i Química OrgànicaUniversitat Rovira i Virgili (URV) C/Marcel·l. Domingo 1 43007 Tarragona Spain
- Kamleon Ventures SL Av. Països Catalans 18 43007 Tarragona Spain
| | - Pascal Blondeau
- Departament de Química Analítica i Química OrgànicaUniversitat Rovira i Virgili (URV) C/Marcel·l. Domingo 1 43007 Tarragona Spain
| | - Francisco J. Andrade
- Departament de Química Analítica i Química OrgànicaUniversitat Rovira i Virgili (URV) C/Marcel·l. Domingo 1 43007 Tarragona Spain
| |
Collapse
|
58
|
Wearable sensors for monitoring the physiological and biochemical profile of the athlete. NPJ Digit Med 2019; 2:72. [PMID: 31341957 PMCID: PMC6646404 DOI: 10.1038/s41746-019-0150-9] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 07/08/2019] [Indexed: 12/21/2022] Open
Abstract
Athletes are continually seeking new technologies and therapies to gain a competitive edge to maximize their health and performance. Athletes have gravitated toward the use of wearable sensors to monitor their training and recovery. Wearable technologies currently utilized by sports teams monitor both the internal and external workload of athletes. However, there remains an unmet medical need by the sports community to gain further insight into the internal workload of the athlete to tailor recovery protocols to each athlete. The ability to monitor biomarkers from saliva or sweat in a noninvasive and continuous manner remain the next technological gap for sports medical personnel to tailor hydration and recovery protocols per the athlete. The emergence of flexible and stretchable electronics coupled with the ability to quantify biochemical analytes and physiological parameters have enabled the detection of key markers indicative of performance and stress, as reviewed in this paper.
Collapse
|
59
|
Baker LB. Physiology of sweat gland function: The roles of sweating and sweat composition in human health. Temperature (Austin) 2019; 6:211-259. [PMID: 31608304 PMCID: PMC6773238 DOI: 10.1080/23328940.2019.1632145] [Citation(s) in RCA: 242] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/06/2019] [Accepted: 06/08/2019] [Indexed: 12/21/2022] Open
Abstract
The purpose of this comprehensive review is to: 1) review the physiology of sweat gland function and mechanisms determining the amount and composition of sweat excreted onto the skin surface; 2) provide an overview of the well-established thermoregulatory functions and adaptive responses of the sweat gland; and 3) discuss the state of evidence for potential non-thermoregulatory roles of sweat in the maintenance and/or perturbation of human health. The role of sweating to eliminate waste products and toxicants seems to be minor compared with other avenues of excretion via the kidneys and gastrointestinal tract; as eccrine glands do not adapt to increase excretion rates either via concentrating sweat or increasing overall sweating rate. Studies suggesting a larger role of sweat glands in clearing waste products or toxicants from the body may be an artifact of methodological issues rather than evidence for selective transport. Furthermore, unlike the renal system, it seems that sweat glands do not conserve water loss or concentrate sweat fluid through vasopressin-mediated water reabsorption. Individuals with high NaCl concentrations in sweat (e.g. cystic fibrosis) have an increased risk of NaCl imbalances during prolonged periods of heavy sweating; however, sweat-induced deficiencies appear to be of minimal risk for trace minerals and vitamins. Additional research is needed to elucidate the potential role of eccrine sweating in skin hydration and microbial defense. Finally, the utility of sweat composition as a biomarker for human physiology is currently limited; as more research is needed to determine potential relations between sweat and blood solute concentrations.
Collapse
Affiliation(s)
- Lindsay B Baker
- Gatorade Sports Science Institute, PepsiCo R&D Physiology and Life Sciences, Barrington, IL, USA
| |
Collapse
|
60
|
Barnes KA, Anderson ML, Stofan JR, Dalrymple KJ, Reimel AJ, Roberts TJ, Randell RK, Ungaro CT, Baker LB. Normative data for sweating rate, sweat sodium concentration, and sweat sodium loss in athletes: An update and analysis by sport. J Sports Sci 2019; 37:2356-2366. [DOI: 10.1080/02640414.2019.1633159] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
61
|
Parrilla M, Ortiz-Gómez I, Cánovas R, Salinas-Castillo A, Cuartero M, Crespo GA. Wearable Potentiometric Ion Patch for On-Body Electrolyte Monitoring in Sweat: Toward a Validation Strategy to Ensure Physiological Relevance. Anal Chem 2019; 91:8644-8651. [DOI: 10.1021/acs.analchem.9b02126] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Marc Parrilla
- Department of Chemistry, School of Engineering Science in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Teknikringen 30, SE-100 44 Stockholm, Sweden
| | - Inmaculada Ortiz-Gómez
- Department of Chemistry, School of Engineering Science in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Teknikringen 30, SE-100 44 Stockholm, Sweden
- Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, 18071 Granada, Spain
| | - Rocío Cánovas
- Department of Chemistry, School of Engineering Science in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Teknikringen 30, SE-100 44 Stockholm, Sweden
| | - Alfonso Salinas-Castillo
- Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, 18071 Granada, Spain
| | - María Cuartero
- Department of Chemistry, School of Engineering Science in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Teknikringen 30, SE-100 44 Stockholm, Sweden
| | - Gastón A. Crespo
- Department of Chemistry, School of Engineering Science in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Teknikringen 30, SE-100 44 Stockholm, Sweden
| |
Collapse
|
62
|
|
63
|
Relf R, Willmott A, Flint MS, Beale L, Maxwell N. Reliability of a wearable sweat rate monitor and routine sweat analysis techniques under heat stress in females. J Therm Biol 2018; 79:209-217. [PMID: 30612681 DOI: 10.1016/j.jtherbio.2018.12.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/17/2018] [Accepted: 12/17/2018] [Indexed: 11/17/2022]
Abstract
INTRODUCTION The aim of the study was to evaluate the reliability of five different sweat analysis techniques which measure; whole body sweat rate [WBSR], local sweat rate [LSR] (via technical absorbent [TA] method and KuduSmart® monitor), sweat conductivity [SC] and sweat gland activation [SGA] in a female population when exercising moderately under heat stress. METHODS Fourteen females (age; 26 ± 7 years, body mass; 66.5 ± 7.6 kg, height; 167.1 ± 6.4 cm) completed a preliminary threshold walking test (to determine exercise intensity) and two main trials, separated by 2 days. Main trials consisted of 30-min seated rest in the environmental chamber (35 °C, 50% relative humidity) in an upper body sauna-suit, before its removal, and walking at a moderate intensity (4 metabolic equivalents) for 30-min (speeds ranged from 4.8 to 6.5 km h-1). WBSR was measured via nude mass pre and post exercise. The TA and Tegaderm patches (for sweat sodium chloride) were placed on the back, forearm and chest for the entire 60-min, replicated for all participants for both trials. SGA was assessed following the 60-min trial and the KuduSmart® monitor was placed on the left arm for the 30-min of exercise. RESULTS WBSR, LSR methods and SC demonstrated no difference between trials (p > 0.05), good agreement (within limits), strong correlations (r ≥ 0.88) and low typical error of measurements [TEM] (< 0.04 L min-1, 0.13 mg min-1 cm-2 and 8 mmol L-1, respectively). SGA method showed moderate intra-class correlation (r = 0.80), with high TEM (5 glands) and large limits of agreement. CONCLUSION Sudomotor function is reliable, as demonstrated by good reliability, small TEM and strong correlations. The use of these sweat techniques is appropriate and practical in females who are exercising at moderate intensity under heat stress, and so, may aid future interventions. SGA shows larger variation and should be used with caution.
Collapse
Affiliation(s)
- Rebecca Relf
- Environmental Extremes Laboratory, University of Brighton, Eastbourne BN20 7SR, UK.
| | - Ashley Willmott
- Environmental Extremes Laboratory, University of Brighton, Eastbourne BN20 7SR, UK
| | - Melanie S Flint
- Cancer Stress Laboratory, University of Brighton, Moulsecoomb BN24GJ, UK; Centre for Stress and Age-Related Disease, Brighton, East Sussex, UK
| | - Louisa Beale
- Environmental Extremes Laboratory, University of Brighton, Eastbourne BN20 7SR, UK
| | - Neil Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne BN20 7SR, UK
| |
Collapse
|
64
|
Baker LB, De Chavez PJD, Ungaro CT, Sopeña BC, Nuccio RP, Reimel AJ, Barnes KA. Exercise intensity effects on total sweat electrolyte losses and regional vs. whole-body sweat [Na +], [Cl -], and [K +]. Eur J Appl Physiol 2018; 119:361-375. [PMID: 30523403 PMCID: PMC6373370 DOI: 10.1007/s00421-018-4048-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/28/2018] [Indexed: 12/01/2022]
Abstract
Purpose To quantify total sweat electrolyte losses at two relative exercise intensities and determine the effect of workload on the relation between regional (REG) and whole body (WB) sweat electrolyte concentrations. Methods Eleven recreational athletes (7 men, 4 women; 71.5 ± 8.4 kg) completed two randomized trials cycling (30 °C, 44% rh) for 90 min at 45% (LOW) and 65% (MOD) of VO2max in a plastic isolation chamber to determine WB sweat [Na+] and [Cl−] using the washdown technique. REG sweat [Na+] and [Cl−] were measured at 11 REG sites using absorbent patches. Total sweat electrolyte losses were the product of WB sweat loss (WBSL) and WB sweat electrolyte concentrations. Results WBSL (0.86 ± 0.15 vs. 1.27 ± 0.24 L), WB sweat [Na+] (32.6 ± 14.3 vs. 52.7 ± 14.6 mmol/L), WB sweat [Cl−] (29.8 ± 13.6 vs. 52.5 ± 15.6 mmol/L), total sweat Na+ loss (659 ± 340 vs. 1565 ± 590 mg), and total sweat Cl− loss (931 ± 494 vs. 2378 ± 853 mg) increased significantly (p < 0.05) from LOW to MOD. REG sweat [Na+] and [Cl−] increased from LOW to MOD at all sites except thigh and calf. Intensity had a significant effect on the regression model predicting WB from REG at the ventral wrist, lower back, thigh, and calf for sweat [Na+] and [Cl−]. Conclusion Total sweat Na+ and Cl− losses increased by ~ 150% with increased exercise intensity. Regression equations can be used to predict WB sweat [Na+] and [Cl−] from some REG sites (e.g., dorsal forearm) irrespective of intensity (between 45 and 65% VO2max), but other sites (especially ventral wrist, lower back, thigh, and calf) require separate prediction equations accounting for workload.
Collapse
Affiliation(s)
- Lindsay B Baker
- Gatorade Sports Science Institute, 617 W. Main St., 60010, Barrington, IL, USA.
| | | | - Corey T Ungaro
- Gatorade Sports Science Institute, 617 W. Main St., 60010, Barrington, IL, USA
| | - Bridget C Sopeña
- Gatorade Sports Science Institute, 617 W. Main St., 60010, Barrington, IL, USA
| | - Ryan P Nuccio
- Gatorade Sports Science Institute, 617 W. Main St., 60010, Barrington, IL, USA
| | - Adam J Reimel
- Gatorade Sports Science Institute, 617 W. Main St., 60010, Barrington, IL, USA
| | - Kelly A Barnes
- Gatorade Sports Science Institute, 617 W. Main St., 60010, Barrington, IL, USA
| |
Collapse
|
65
|
Kaya T, Liu G, Ho J, Yelamarthi K, Miller K, Edwards J, Stannard A. Wearable Sweat Sensors: Background and Current Trends. ELECTROANAL 2018. [DOI: 10.1002/elan.201800677] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Tolga Kaya
- School of Computer Science and Engineering; Sacred Heart University; Fairfield, CT 06825 USA
| | - Gengchen Liu
- Department of Electrical and Computer Engineering; University of California at Davis; Davis 95616 USA
| | - Jenny Ho
- Nexteer Automative Engineering; Saginaw, MI 48601 USA
| | - Kumar Yelamarthi
- School of Engineering and Technology; Central Michigan University; Mount Pleasant, MI 48859 USA
| | - Kevin Miller
- School of Health Sciences; Central Michigan University; Mount Pleasant 48859 USA
| | - Jeffrey Edwards
- School of Health Sciences; Central Michigan University; Mount Pleasant 48859 USA
| | - Alicja Stannard
- Exercise Science program; Sacred Heart University; Fairfield, CT 06825 USA
| |
Collapse
|
66
|
Harshman SW, Pitsch RL, Smith ZK, O’Connor ML, Geier BA, Qualley AV, Schaeublin NM, Fischer MV, Eckerle JJ, Strang AJ, Martin JA. The proteomic and metabolomic characterization of exercise-induced sweat for human performance monitoring: A pilot investigation. PLoS One 2018; 13:e0203133. [PMID: 30383773 PMCID: PMC6211630 DOI: 10.1371/journal.pone.0203133] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 08/15/2018] [Indexed: 12/01/2022] Open
Abstract
Sweat is a biofluid with several attractive attributes. However, investigation into sweat for biomarker discovery applications is still in its infancy. To add support for the use of sweat as a non-invasive media for human performance monitoring, volunteer participants were subjected to a physical exertion model using a treadmill. Following exercise, sweat was collected, aliquotted, and analyzed for metabolite and protein content via high-resolution mass spectrometry. Overall, the proteomic analysis illustrates significant enrichment steps will be required for proteomic biomarker discovery from single sweat samples as protein abundance is low in this medium. Furthermore, the results indicate a potential for protein degradation, or a large number of low molecular weight protein/peptides, in these samples. Metabolomic analysis shows a strong correlation in the overall abundance among sweat metabolites. Finally, hierarchical clustering of participant metabolite abundances show trends emerging, although no significant trends were observed (alpha = 0.8, lambda = 1 standard error via cross validation). However, these data suggest with a greater number of biological replicates, stronger, statistically significant results, can be obtained. Collectively, this study represents the first to simultaneously use both proteomic and metabolomic analysis to investigate sweat. These data highlight several pitfalls of sweat analysis for biomarker discovery applications.
Collapse
Affiliation(s)
- Sean W. Harshman
- UES Inc., Air Force Research Laboratory, Wright- Patterson Air Force Base, Ohio, United States of America
- * E-mail:
| | - Rhonda L. Pitsch
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio, United States of America
| | - Zachary K. Smith
- UES Inc., Air Force Research Laboratory, Wright- Patterson Air Force Base, Ohio, United States of America
| | - Maegan L. O’Connor
- Oak Ridge Institute of Science & Education, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio, United States of America
| | - Brian A. Geier
- Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio, United States of America
| | - Anthony V. Qualley
- UES Inc., Air Force Research Laboratory, Wright- Patterson Air Force Base, Ohio, United States of America
| | - Nicole M. Schaeublin
- UES Inc., Air Force Research Laboratory, Wright- Patterson Air Force Base, Ohio, United States of America
| | - Molly V. Fischer
- Oak Ridge Institute of Science & Education, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio, United States of America
| | - Jason J. Eckerle
- InfoSciTex Corp., Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio, United States of America
| | - Adam J. Strang
- Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio, United States of America
| | - Jennifer A. Martin
- Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio, United States of America
| |
Collapse
|
67
|
Agrawal K, Sivamani RK, Newman JW. Noninvasive profiling of sweat-derived lipid mediators for cutaneous research. Skin Res Technol 2018; 25:3-11. [PMID: 30030941 DOI: 10.1111/srt.12617] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND OBJECTIVE Recent increases in the use of noninvasive matrices for biomedical analysis has led to interest in the evaluation of sweat for both clinical and research applications. However, despite being one of the two main cutaneous secretions, until very recently, only one study actually analyzed sweat in the context of cutaneous disease. This review attempts to make the case for increased use of sweat in cutaneous research, and discusses lipid mediators as potential analytical targets in sweat. METHODS Sweat composition and its relationship with the skin and systemic circulation are discussed, as are practical considerations for sweat sampling and analysis. Previous analyses of lipid mediators in skin biopsies are provided to show that lipid mediators can regulate cutaneous processes and disease pathways. Summaries of recent studies involving the analysis of sweat lipid mediators are provided to demonstrate the utility of sweat lipid mediator testing to support future cutaneous research studies. RESULTS Sweat has the potential to reflect both local and systemic biochemical changes in response to disease or intervention, and two recent studies of sweat lipid mediators confirm this ability. Additionally, sweat lipid mediators appear to be temporally stable with individual variability comparable to other matrices, suggesting that these analytes could be useful biomarkers. CONCLUSIONS Sweat metabolites may be capable of reporting changes in cutaneous biochemical pathways, thereby providing insight into the immunomodulatory biochemistry of the skin. Lipid mediator analysis of sweat appears to be a non invasive approach that could enhance existing cutaneous research and diagnostic methodologies.
Collapse
Affiliation(s)
- Karan Agrawal
- Department of Nutrition, University of California-Davis, Davis, California.,West Coast Metabolomics Center, Genome Center, Davis, California
| | - Raja K Sivamani
- Department of Dermatology, University of California-Davis Medical Center, Sacramento, California.,Department of Biological Sciences, California State University-Sacramento, Sacramento, California
| | - John W Newman
- Department of Nutrition, University of California-Davis, Davis, California.,West Coast Metabolomics Center, Genome Center, Davis, California.,United States Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, Davis, California
| |
Collapse
|
68
|
Black KE, Black AD, Baker D, Fairbairn K. Body mass changes during training in elite rugby union: Is a single test of hydration indices reliable? Eur J Sport Sci 2018; 18:1049-1057. [PMID: 29806987 DOI: 10.1080/17461391.2018.1470677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
There is limited research studying fluid and electrolyte balance in rugby union players, and a paucity of information regarding the test-retest reliability. This study describes the fluid balance of elite rugby union players across multiple squads and the reliability of fluid balance measures between two equivalent training sessions. Sixty-one elite rugby players completed a single fluid balance testing session during a game simulation training session. A subsample of 21 players completed a second fluid balance testing session during an equivalent training session. Players were weighed in minimal clothing before and after each training session. Each player was provided with their own drinks which were weighed before and after each training session. More players gained body weight (9 (14.8%)) during training than lost greater than 2% of their initial body mass (1 (1.6%)). Pre-training body mass and rate of fluid loss were significantly associated (r = 0.318, p = .013). There was a significant correlation between rate of fluid loss in sessions 1 (1.74 ± 0.32 L h-1) and 2 (1.10 ± 0.31 L. h-1), (r = 0.470, p = .032). This could be useful for nutritionists working with rugby squads to identify players with high sweat losses.
Collapse
Affiliation(s)
| | | | - Dane Baker
- c Chiefs Super Franchise , Hamilton , New Zealand
| | - Kirsty Fairbairn
- d Advanced Sports Dietitian , Invigorate Nutrition , Dunedin , New Zealand
| |
Collapse
|
69
|
Sweating Rate and Sweat Sodium Concentration in Athletes: A Review of Methodology and Intra/Interindividual Variability. Sports Med 2018; 47:111-128. [PMID: 28332116 PMCID: PMC5371639 DOI: 10.1007/s40279-017-0691-5] [Citation(s) in RCA: 182] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Athletes lose water and electrolytes as a consequence of thermoregulatory sweating during exercise and it is well known that the rate and composition of sweat loss can vary considerably within and among individuals. Many scientists and practitioners conduct sweat tests to determine sweat water and electrolyte losses of athletes during practice and competition. The information gleaned from sweat testing is often used to guide personalized fluid and electrolyte replacement recommendations for athletes; however, unstandardized methodological practices and challenging field conditions can produce inconsistent/inaccurate results. The primary objective of this paper is to provide a review of the literature regarding the effect of laboratory and field sweat-testing methodological variations on sweating rate (SR) and sweat composition (primarily sodium concentration [Na+]). The simplest and most accurate method to assess whole-body SR is via changes in body mass during exercise; however, potential confounding factors to consider are non-sweat sources of mass change and trapped sweat in clothing. In addition, variability in sweat [Na+] can result from differences in the type of collection system used (whole body or localized), the timing/duration of sweat collection, skin cleaning procedure, sample storage/handling, and analytical technique. Another aim of this paper is to briefly review factors that may impact intra/interindividual variability in SR and sweat [Na+] during exercise, including exercise intensity, environmental conditions, heat acclimation, aerobic capacity, body size/composition, wearing of protective equipment, sex, maturation, aging, diet, and/or hydration status. In summary, sweat testing can be a useful tool to estimate athletes’ SR and sweat Na+ loss to help guide fluid/electrolyte replacement strategies, provided that data are collected, analyzed, and interpreted appropriately.
Collapse
|
70
|
Sweat Sodium, Potassium, and Chloride Concentrations Analyzed Same Day as Collection Versus After 7 Days Storage in a Range of Temperatures. Int J Sport Nutr Exerc Metab 2018; 28:238-245. [PMID: 29140143 DOI: 10.1123/ijsnem.2017-0199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The purpose of this study was to determine the effect of storage temperature on sodium ([Na+]), potassium ([K+]), and chloride ([Cl-]) concentrations of sweat samples analyzed 7 days after collection. Using the absorbent patch technique, 845 sweat samples were collected from 39 subjects (32 ± 7 years, 72.9 ± 10.5 kg) during exercise. On the same day as collection (PRESTORAGE), 609 samples were analyzed for [Na+], [Cl-], and [K+] by ion chromatography (IC) and 236 samples were analyzed for [Na+] using a compact ion-selective electrode (ISE). Samples were stored at one of the four conditions: -20 °C (IC, n = 138; ISE, n = 60), 8 °C (IC, n = 144; ISE, n = 59), 23 °C (IC, n = 159; ISE, n = 59), or alternating between 8 °C and 23 °C (IC, n = 168; ISE, n = 58). After 7 days in storage (POSTSTORAGE), samples were reanalyzed using the same technique as PRESTORAGE. PRESTORAGE sweat electrolyte concentrations were highly related to that of POSTSTORAGE (intraclass correlation coefficient: .945-.989, p < .001). Mean differences (95% confidence intervals) between PRESTORAGE and POSTSTORAGE were statistically, but not practically, significant for most comparisons: IC [Na+]: -0.5(0.9) to -2.1(0.9) mmol/L; IC [K+]: -0.1(0.1) to -0.2(0.1) mmol/L; IC [Cl-]: -0.4(1.4) to -1.3(1.3) mmol/L; ISE [Na+]: -2.0(1.1) to 1.3(1.1) mmol/L. Based on typical error of measurement results, 95% of the time PRESTORAGE and POSTSTORAGE sweat [Na+], [K+], and [Cl-] by IC analysis fell within ±7-9, ±0.6-0.7, and ±9-13 mmol/L, respectively, while sweat [Na+] by ISE was ±6 mmol/L. All conditions produced high reliability and acceptable levels of agreement in electrolyte concentrations of sweat samples analyzed on the day of collection versus after 7 days in storage.
Collapse
|
71
|
Shah SR, Bhave G. Using Electrolyte Free Water Balance to Rationalize and Treat Dysnatremias. Front Med (Lausanne) 2018; 5:103. [PMID: 29740578 PMCID: PMC5925609 DOI: 10.3389/fmed.2018.00103] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 03/29/2018] [Indexed: 01/07/2023] Open
Abstract
Dysnatremias or abnormalities in plasma [Na+] are often termed disorders of water balance, an unclear physiologic concept often confused with changes in total fluid balance. However, most clinicians clearly recognize that hypertonic or hypotonic gains or losses alter plasma [Na+], while isotonic changes do not modify plasma [Na+]. This concept can be conceptualized as the electrolyte free water balance (EFWB), which defines the non-isotonic components of inputs and outputs to determine their effect on plasma [Na+]. EFWB is mathematically proportional to the rate of change in plasma [Na+] (dPNa/dt) and, therefore, is actively regulated to zero so that plasma [Na+] remains stable at its homeostatic set point. Dysnatremias are, therefore, disorders of EFWB and the relationship between EFWB and dPNa/dt provides a rationale for therapeutic strategies incorporating mass and volume balance. Herein, we leverage dPNa/dt as a desired rate of correction of plasma [Na+] to define a stepwise approach for the treatment of dysnatremias.
Collapse
Affiliation(s)
- Sanjeev R. Shah
- Renal-Electrolyte and Hypertension Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Gautam Bhave
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| |
Collapse
|
72
|
Brueck A, Iftekhar T, Stannard AB, Yelamarthi K, Kaya T. A Real-Time Wireless Sweat Rate Measurement System for Physical Activity Monitoring. SENSORS 2018; 18:s18020533. [PMID: 29439398 PMCID: PMC5855985 DOI: 10.3390/s18020533] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/26/2018] [Accepted: 02/08/2018] [Indexed: 02/02/2023]
Abstract
There has been significant research on the physiology of sweat in the past decade, with one of the main interests being the development of a real-time hydration monitor that utilizes sweat. The contents of sweat have been known for decades; sweat provides significant information on the physiological condition of the human body. However, it is important to know the sweat rate as well, as sweat rate alters the concentration of the sweat constituents, and ultimately affects the accuracy of hydration detection. Towards this goal, a calorimetric based flow-rate detection system was built and tested to determine sweat rate in real time. The proposed sweat rate monitoring system has been validated through both controlled lab experiments (syringe pump) and human trials. An Internet of Things (IoT) platform was embedded, with the sensor using a Simblee board and Raspberry Pi. The overall prototype is capable of sending sweat rate information in real time to either a smartphone or directly to the cloud. Based on a proven theoretical concept, our overall system implementation features a pioneer device that can truly measure the rate of sweat in real time, which was tested and validated on human subjects. Our realization of the real-time sweat rate watch is capable of detecting sweat rates as low as 0.15 µL/min/cm², with an average error in accuracy of 18% compared to manual sweat rate readings.
Collapse
Affiliation(s)
- Andrew Brueck
- School of Engineering and Technology, Central Michigan University, Mt Pleasant, MI 48859, USA.
| | - Tashfin Iftekhar
- School of Engineering and Technology, Central Michigan University, Mt Pleasant, MI 48859, USA.
| | - Alicja B Stannard
- Department of Physical Therapy and Human Movement Science, Sacred Heart University, Fairfield, CT 06825, USA.
| | - Kumar Yelamarthi
- School of Engineering and Technology, Central Michigan University, Mt Pleasant, MI 48859, USA.
| | - Tolga Kaya
- School of Computing, Sacred Heart University, Fairfield, CT 06825, USA.
| |
Collapse
|
73
|
Baker LB, Ungaro CT, Sopeña BC, Nuccio RP, Reimel AJ, Carter JM, Stofan JR, Barnes KA. Body map of regional vs. whole body sweating rate and sweat electrolyte concentrations in men and women during moderate exercise-heat stress. J Appl Physiol (1985) 2018; 124:1304-1318. [PMID: 29420145 DOI: 10.1152/japplphysiol.00867.2017] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
This study determined the relations between regional (REG) and whole body (WB) sweating rate (RSR and WBSR, respectively) as well as REG and WB sweat Na+ concentration ([Na+]) during exercise. Twenty-six recreational athletes (17 men, 9 women) cycled for 90 min while WB sweat [Na+] was measured using the washdown technique. RSR and REG sweat [Na+] were measured from nine regions using absorbent patches. RSR and REG sweat [Na+] from all regions were significantly ( P < 0.05) correlated with WBSR ( r = 0.58-0.83) and WB sweat [Na+] ( r = 0.74-0.88), respectively. However, the slope and y-intercept of the regression lines for most models were significantly different than 1 and 0, respectively. The coefficients of determination ( r2) were 0.44-0.69 for RSR predicting WBSR [best predictors: dorsal forearm ( r2 = 0.62) and triceps ( r2 = 0.69)] and 0.55-0.77 for REG predicting WB sweat [Na+] [best predictors: ventral forearm ( r2 = 0.73) and thigh ( r2 = 0.77)]. There was a significant ( P < 0.05) effect of day-to-day variability on the regression model predicting WBSR from RSR at most regions but no effect on predictions of WB sweat [Na+] from REG. Results suggest that REG cannot be used as a direct surrogate for WB sweating responses. Nonetheless, the use of regression equations to predict WB sweat [Na+] from REG can provide an estimation of WB sweat [Na+] with an acceptable level of accuracy, especially using the forearm or thigh. However, the best practice for measuring WBSR remains conventional WB mass balance calculations since prediction of WBSR from RSR using absorbent patches does not meet the accuracy or reliability required to inform fluid intake recommendations. NEW & NOTEWORTHY This study developed a body map of regional sweating rate and regional (REG) sweat electrolyte concentrations and determined the effect of within-subject (bilateral and day-to-day) and between-subject (sex) factors on the relations between REG and the whole body (WB). Regression equations can be used to predict WB sweat Na+ concentration from REG, especially using the forearm or thigh. However, prediction of WB sweating rate from REG sweating rate using absorbent patches does not reach the accuracy or reliability required to inform fluid intake recommendations.
Collapse
Affiliation(s)
| | - Corey T Ungaro
- Gatorade Sports Science Institute , Barrington, Illinois
| | | | - Ryan P Nuccio
- Gatorade Sports Science Institute , Barrington, Illinois
| | - Adam J Reimel
- Gatorade Sports Science Institute , Barrington, Illinois
| | - James M Carter
- Gatorade Sports Science Institute , Barrington, Illinois
| | - John R Stofan
- Gatorade Sports Science Institute , Barrington, Illinois
| | - Kelly A Barnes
- Gatorade Sports Science Institute , Barrington, Illinois
| |
Collapse
|
74
|
Choi J, Ghaffari R, Baker LB, Rogers JA. Skin-interfaced systems for sweat collection and analytics. SCIENCE ADVANCES 2018; 4:eaar3921. [PMID: 29487915 PMCID: PMC5817925 DOI: 10.1126/sciadv.aar3921] [Citation(s) in RCA: 207] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/16/2018] [Indexed: 05/09/2023]
Abstract
Recent interdisciplinary advances in materials, mechanics, and microsystem designs for biocompatible electronics, soft microfluidics, and electrochemical biosensors establish the foundations for emerging classes of thin, skin-interfaced platforms capable of capturing, storing, and performing quantitative, spatiotemporal measurements of sweat chemistry, instantaneous local sweat rate, and total sweat loss. This review summarizes scientific and technical progress in this area and highlights the implications in real time and ambulatory modes of deployment during physical activities across a broad range of contexts in clinical health, physiology research, fitness/wellness, and athletic performance.
Collapse
Affiliation(s)
- Jungil Choi
- Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Roozbeh Ghaffari
- Epicore Biosystems Inc., Evanston, IL 60208, USA
- Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL 60208, USA
| | - Lindsay B. Baker
- Gatorade Sports Science Institute, 617 W. Main St., Barrington, IL 60010, USA
| | - John A. Rogers
- Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL 60208, USA
- Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL 60208, USA
- Departments of Biomedical Engineering, Mechanical Engineering, and Electrical Engineering and Computer Science, McCormick School of Engineering, Northwestern University, Evanston, IL 60208, USA
- Department of Chemistry, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL 60208, USA
- Department of Neurological Surgery, Feinberg School of Medicine, and Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA
| |
Collapse
|
75
|
Ranchordas MK, Tiller NB, Ramchandani G, Jutley R, Blow A, Tye J, Drury B. Normative data on regional sweat-sodium concentrations of professional male team-sport athletes. J Int Soc Sports Nutr 2017; 14:40. [PMID: 29093646 PMCID: PMC5661918 DOI: 10.1186/s12970-017-0197-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/22/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The purpose of this paper was to report normative data on regional sweat sweat-sodium concentrations of various professional male team-sport athletes, and to compare sweat-sodium concentrations among sports. Data to this effect would inform our understanding of athlete sodium requirements, thus allowing for the individualisation of sodium replacement strategies. Accordingly, data from 696 athletes (Soccer, n = 270; Rugby, n = 181; Baseball, n = 133; American Football, n = 60; Basketball, n = 52) were compiled for a retrospective analysis. Regional sweat-sodium concentrations were collected using the pilocarpine iontophoresis method, and compared to self-reported measures collected via questionnaire. RESULTS Sweat-sodium concentrations were significantly higher (p < 0.05) in American football (50.4 ± 15.3 mmol·L-1), baseball (54.0 ± 14.0 mmol·L-1), and basketball (48.3 ± 14.0 mmol·L-1) than either soccer (43.2 ± 12.0 mmol·L-1) or rugby (44.0 ± 12.1 mmol·L-1), but with no differences among the N.American or British sports. There were strong positive correlations between sweat-sodium concentrations and self-reported sodium losses in American football (rs = 0.962, p < 0.001), basketball (rs = 0.953, p < 0.001), rugby (rs = 0.813, p < 0.001), and soccer (rs = 0.748, p < 0.001). CONCLUSIONS The normative data provided on sweat-sodium concentrations might assist sports science/medicine practitioners in generating bespoke hydration and electrolyte-replacement strategies to meet the sodium demands of professional team-sport athletes. Moreover, these novel data suggest that self-reported measures of sodium loss might serve as an effective surrogate in the absence of direct measures; i.e., those which are more expensive or non-readily available.
Collapse
Affiliation(s)
- Mayur K. Ranchordas
- Academy of Sport and Physical Acitivty, Sheffield Hallam University, Sheffield, S10 2BP UK
| | - Nicholas B. Tiller
- Academy of Sport and Physical Acitivty, Sheffield Hallam University, Sheffield, S10 2BP UK
| | - Girish Ramchandani
- Sport Industry Research Centre, Sheffield Hallam University, Sheffield, S10 2BP UK
| | - Raj Jutley
- Precision Hydration, 43 Saffron Drive, Christchurch, BH23 4LR UK
| | - Andrew Blow
- Precision Hydration, 43 Saffron Drive, Christchurch, BH23 4LR UK
| | - Jonny Tye
- Precision Hydration, 43 Saffron Drive, Christchurch, BH23 4LR UK
| | - Ben Drury
- Hartpury University Centre, Hartpury, Gloucester, GL19 3BE UK
| |
Collapse
|
76
|
Agrawal K, Waller JD, Pedersen TL, Newman JW. Effects of stimulation technique, anatomical region, and time on human sweat lipid mediator profiles. Prostaglandins Other Lipid Mediat 2017; 134:84-92. [PMID: 28942325 DOI: 10.1016/j.prostaglandins.2017.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 09/19/2017] [Accepted: 09/19/2017] [Indexed: 11/18/2022]
Abstract
Few studies compare sampling protocol effect on sweat composition. Here we evaluate the impact of sweat stimulation mode and site of collection on lipid mediator composition. Sweat from healthy males (n=7) was collected weekly for three weeks from the volar forearm following either pilocarpine iontophoresis or exercise, and from the forearm, back and thigh following pilocarpine iontophoresis only. Sweat content of over 150 lipid mediators were measured by liquid chromatography-tandem mass spectrometry. Seventy lipid mediators were routinely detected, including prostanoids, alcohols, diols, epoxides, ketones, nitrolipids, N-acylethanolamides, monoacylglycerols, and ceramides. Detected lipid mediators appeared unaffected by sampling site, though the forearm was the most consistent source of sweat. Pilocarpine-induced sweat showed increased concentrations of most detected compounds. Moreover, lipid mediator concentrations and profiles were temporally stable over the study duration. Sweat therefore appears to be a consistent and anatomically-stable source of lipid mediators, but care must be taken in comparing results obtained from different stimulation techniques.
Collapse
Affiliation(s)
- Karan Agrawal
- Department of Nutrition, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA; NIH West Coast Metabolomics Center, 451 Health Sciences Drive, Davis, CA 95616, USA.
| | - Justin D Waller
- United States Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, 430 W Health Sciences Drive, Davis, CA 95616, USA.
| | - Theresa L Pedersen
- United States Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, 430 W Health Sciences Drive, Davis, CA 95616, USA; Advanced Analytics, 1718 Amador Way, Woodland, CA 95695, USA.
| | - John W Newman
- Department of Nutrition, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA; NIH West Coast Metabolomics Center, 451 Health Sciences Drive, Davis, CA 95616, USA; United States Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, 430 W Health Sciences Drive, Davis, CA 95616, USA.
| |
Collapse
|
77
|
Vairo D, Bruzzese L, Marlinge M, Fuster L, Adjriou N, Kipson N, Brunet P, Cautela J, Jammes Y, Mottola G, Burtey S, Ruf J, Guieu R, Fenouillet E. Towards Addressing the Body Electrolyte Environment via Sweat Analysis:Pilocarpine Iontophoresis Supports Assessment of Plasma Potassium Concentration. Sci Rep 2017; 7:11801. [PMID: 28924220 PMCID: PMC5603548 DOI: 10.1038/s41598-017-12211-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 08/30/2017] [Indexed: 12/17/2022] Open
Abstract
Electrolyte concentration in sweat depends on environmental context and physical condition but also on the pathophysiological status. Sweat analyzers may be therefore the future way for biological survey although how sweat electrolyte composition can reflect plasma composition remains unclear. We recruited 10 healthy subjects and 6 patients to have a broad range of plasma electrolyte concentrations (chloride, potassium and sodium) and pH. These variables were compared to those found in sweat produced following cycling exercise or pilocarpine iontophoresis, a condition compatible with operating a wearable device. We found no correlation between plasma and sweat parameters when exercise-induced sweat was analyzed, and we could identify a correlation only between plasma and sweat potassium concentration (R = 0.78, p < 0.01) when sweat was induced using pilocarpine iontophoresis. We tested measurement repeatability in sweat at 24hr-interval for 3 days in 4 subjects and found a great intra-individual variability regarding all parameters in exercise-induced sweat whereas similar electrolyte levels were measured in pilocarpine-induced sweat. Thus, electrolyte concentration in sweat sampled following physical activity does not reflect concentration in plasma while pilocarpine iontophoresis appears to be promising to reproducibly address sweat electrolytes, and to make an indirect evaluation of plasma potassium concentration in chronic kidney disease and arrhythmia.
Collapse
Affiliation(s)
- Donato Vairo
- UMR MD2, Aix Marseille University, Marseille, France
| | | | - Marion Marlinge
- Laboratory of Biochemistry, Timone Hospital, Marseille, France
| | - Lea Fuster
- Laboratory of Biochemistry, Timone Hospital, Marseille, France
| | - Nabil Adjriou
- UMR MD2, Aix Marseille University, Marseille, France
| | | | - Philippe Brunet
- Department of Dialysis, Conception Hospital, Marseille, France.,INSERM, U 1076, Marseille, France
| | | | - Yves Jammes
- UMR MD2, Aix Marseille University, Marseille, France
| | | | - Stephane Burtey
- Department of Dialysis, Conception Hospital, Marseille, France.,INSERM, U 1076, Marseille, France
| | - Jean Ruf
- UMR MD2, Aix Marseille University, Marseille, France.,INSERM, Paris, France
| | - Regis Guieu
- UMR MD2, Aix Marseille University, Marseille, France. .,Laboratory of Biochemistry, Timone Hospital, Marseille, France.
| | - Emmanuel Fenouillet
- UMR MD2, Aix Marseille University, Marseille, France.,CNRS, Institut des Sciences Biologiques, Paris, France
| |
Collapse
|
78
|
Goulet EDB, Asselin A, Gosselin J, Baker LB. Measurement of sodium concentration in sweat samples: comparison of 5 analytical techniques. Appl Physiol Nutr Metab 2017; 42:861-868. [PMID: 28407476 DOI: 10.1139/apnm-2017-0059] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sweat sodium concentration (SSC) can be determined using different analytical techniques (ATs), which may have implications for athletes and scientists. This study compared the SSC measured with 5 ATs: ion chromatography (IChr), flame photometry (FP), direct (DISE) and indirect (IISE) ion-selective electrode, and ion conductivity (IC). Seventy sweat samples collected from 14 athletes were analyzed with 5 instruments: the 883 Basic IC Plus (IChr, reference instrument), AAnalyst 200 (FP), Cobas 6000 (IISE), Sweat-Chek (IC), and B-722 Laqua Twin (DISE). Instruments showed excellent relative (intraclass correlation coefficient (ICC) ≥ 0.999) and absolute (coefficient of variation (CV) ≤ 2.6%) reliability. Relative validity was also excellent between ATs (ICC ≥ 0.961). In regards to the inter-AT absolute validity, compared with IChr, standard error of the estimates were similar among ATs (2.8-3.8 mmol/L), but CV was lowest with DISE (3.9%), intermediate with IISE (7.6%), and FP (6.9%) and highest with IC (12.3%). In conclusion, SSC varies depending on the AT used to analyze samples. Therefore, results obtained from different ATs are scarcely comparable and should not be used interchangeably. Nevertheless, taking into account the normal variability in SSC (∼±12%), the imprecision of the recommendations deriving from FP, IISE, IC, and DISE should have trivial health and physiological consequences under most exercise circumstances.
Collapse
Affiliation(s)
- Eric D B Goulet
- a Faculty of Physical Activity Sciences, Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.,b Research Centre on Aging, University of Sherbrooke, Sherbrooke, J1H 4C4, Canada
| | - Audrey Asselin
- a Faculty of Physical Activity Sciences, Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.,b Research Centre on Aging, University of Sherbrooke, Sherbrooke, J1H 4C4, Canada
| | - Jonathan Gosselin
- a Faculty of Physical Activity Sciences, Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.,b Research Centre on Aging, University of Sherbrooke, Sherbrooke, J1H 4C4, Canada
| | - Lindsay B Baker
- c Gatorade Sports Science Institute, Barrington, IL 60010, USA
| |
Collapse
|
79
|
Ferreira FG, Fassarella M, Costa NMB, Santana ÂMC, Marins JCB. PERDA ELETROLÍTICA DE CÁLCIO, MAGNÉSIO E FERRO NO SUOR DURANTE CORRIDA EM ESTEIRA. REV BRAS MED ESPORTE 2017. [DOI: 10.1590/1517-869220172301131306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
RESUMO Introdução: O suor e sua consequente evaporação são fundamentais para manutenção da temperatura corporal durante o exercício. Objetivo: Avaliar a perda de cálcio (Ca++), magnésio (Mg++) e ferro (Fe++) no suor de corredores e de indivíduos ativos. Métodos: Foram avaliados 15 atletas corredores de fundo {VO2máx = 68 ± 5,4 ml(kg.min)-1} e 15 indivíduos ativos não atletas {VO2máx = 50,3 ± 6,3 ml(kg.min)-1}, com média de idade, respectivamente, de 25,3 ± 2,4 e 23,1 ± 4,3 anos. Ambos os grupos se exercitaram por 80 minutos em esteira, com intensidade de 75% a 85% da frequência cardíaca de reserva, e ingeriram 3 ml de água/kg de peso corporal a cada 15 minutos. As condições ambientais da prova foram 21,9 ± 1,5 °C e 89,2 ± 5,6% de umidade relativa para os atletas e 21,8 ± 1,6 °C e 93,2 ± 3,5% de UR para os ativos. As amostras de suor foram coletadas em intervalos regulares de 20 minutos nas regiões do peito, torácica e lombar das costas, para posterior análise dos minerais Ca++, Mg++ e Fe++ por espectrofotômetro de absorção atômica. Resultados: Não foram registradas diferenças significativas para os minerais em função do nível de condicionamento. Observou-se tendência à diminuição na concentração do Mg++ e Fe++ do suor ao longo do exercício. Conclusão: Nas condições ambientais e de exercício estudadas, o condicionamento não interfere na perda de Ca++, Mg++ e Fe++.
Collapse
|
80
|
Roberts WO, Dorman JC, Bergeron MF. Recurrent Heat Stroke in a Runner: Race Simulation Testing for Return to Activity. Med Sci Sports Exerc 2017; 48:785-9. [PMID: 26694842 DOI: 10.1249/mss.0000000000000847] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Exertional heat stroke (EHS) occurs in distance runners and is a life-threatening condition. A 30-yr-old healthy recreational male distance runner (CR) collapsed at the 12-mile mark in two half marathon races 6 wk apart in fall 2009. In both episodes, CR was found on the ground confused, incoherent, sweaty, and warm to touch. The emergency medical team responded, and he was treated empirically for suspected EHS by cooling en route to the emergency department. In the emergency department, rectal temperatures were 40°C and 40.5°C for each episode, respectively. The first race start temperature was 16°C with 94% relative humidity (RH), and the second was 3°C, 75% RH. Heat tolerance test was within the normal range indicating low EHS risk. A race simulation test (environmental chamber, 25°C, 60% RH) at a treadmill pace of 10.5-12.9 km·h was stopped at 70 min coincident with a rectal temperature of 39.5°C. CR's body weight dropped 3.49 kg with an estimated sweat loss of 4.09 L and an estimated total sweat Na loss of 7610 mg. We recommended that he limit his runs to <1 h and replace salt and fluid during and (mostly) after activity, run with a partner, acclimate to heat before racing, and reduce his pace or stop at the first sign of symptoms. Race simulation testing should be considered in athletes with recurrent EHS to assist with the return-to-activity recommendation.
Collapse
Affiliation(s)
- William O Roberts
- 1Department of Family Medicine and Community Health, University of Minnesota, Minneapolis, MN; 2Sanford Sports Science Institute, Sanford Health, Sioux Falls, SD; 3Youth Sports of the Americas, Birmingham, AL; 4Lemak Health, Birmingham, AL
| | | | | |
Collapse
|
81
|
Turck D, Bresson JL, Burlingame B, Dean T, Fairweather-Tait S, Heinonen M, Hirsch-Ernst KI, Mangelsdorf I, McArdle H, Neuhäuser-Berthold M, Nowicka G, Pentieva K, Sanz Y, Siani A, Sjödin A, Stern M, Tomé D, Van Loveren H, Vinceti M, Willatts P, Aggett P, Martin A, Przyrembel H, Brönstrup A, Ciok J, Gómez Ruiz JÁ, de Sesmaisons-Lecarré A, Naska A. Dietary reference values for potassium. EFSA J 2016. [DOI: 10.2903/j.efsa.2016.4592] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
|
82
|
Lara B, Gallo-Salazar C, Puente C, Areces F, Salinero JJ, Del Coso J. Interindividual variability in sweat electrolyte concentration in marathoners. J Int Soc Sports Nutr 2016; 13:31. [PMID: 27478425 PMCID: PMC4966593 DOI: 10.1186/s12970-016-0141-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/07/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Sodium (Na(+)) intake during exercise aims to replace the Na(+) lost by sweat to avoid electrolyte imbalances, especially in endurance disciplines. However, Na(+) needs can be very different among individuals because of the great inter-individual variability in sweat electrolyte concentration. The aim of this investigation was to determine sweat electrolyte concentration in a large group of marathoners. METHODS A total of 157 experienced runners (141 men and 16 women) completed a marathon race (24.4 ± 3.6 °C and 27.7 ± 4.8 % of humidity). During the race, sweat samples were collected by using sweat patches placed on the runners' forearms. Sweat electrolyte concentration was measured by using photoelectric flame photometry. RESULTS As a group, sweat Na(+) concentration was 42.9 ± 18.7 mmol·L(-1) (minimal-maximal value = 7.0-95.5 mmol·L(-1)), sweat Cl(-) concentration was 32.2 ± 15.6 mmol·L(-1) (7.3-90.6 mmol·L(-1)) and sweat K(+) concentration was 6.0 ± 0.9 mmol·L(-1) (3.1-8.0 mmol·L(-1)). Women presented lower sweat Na(+) (33.9 ± 12.1 vs 44.0 ± 19.1 mmol·L(-1); P = 0.04) and sweat Cl(-) concentrations (22.9 ± 10.5 vs 33.2 ± 15.8 mmol·L(-1); P = 0.01) than men. A 20 % of individuals presented a sweat Na(+) concentration higher than 60 mmol·L(-1) while this threshold was not surpassed by any female marathoner. Sweat electrolyte concentration did not correlate to sweat rate, age, body characteristics, experience or training. Although there was a significant correlation between sweat Na(+) concentration and running pace (r = 0.18; P = 0.03), this association was weak to interpret that sweat Na(+) concentration increased with running pace. CONCLUSIONS The inter-individual variability in sweat electrolyte concentration was not explained by any individual characteristics except for individual running pace and sex. An important portion (20 %) of marathoners might need special sodium intake recommendations due to their high sweat salt losses.
Collapse
Affiliation(s)
- Beatriz Lara
- Camilo José Cela University Exercise Physiology Laboratory, C/ Castillo de Alarcon, 49, Villafranca del Castillo, 28692 Spain
| | - César Gallo-Salazar
- Camilo José Cela University Exercise Physiology Laboratory, C/ Castillo de Alarcon, 49, Villafranca del Castillo, 28692 Spain
| | - Carlos Puente
- Camilo José Cela University Exercise Physiology Laboratory, C/ Castillo de Alarcon, 49, Villafranca del Castillo, 28692 Spain
| | - Francisco Areces
- Camilo José Cela University Exercise Physiology Laboratory, C/ Castillo de Alarcon, 49, Villafranca del Castillo, 28692 Spain
| | - Juan José Salinero
- Camilo José Cela University Exercise Physiology Laboratory, C/ Castillo de Alarcon, 49, Villafranca del Castillo, 28692 Spain
| | - Juan Del Coso
- Camilo José Cela University Exercise Physiology Laboratory, C/ Castillo de Alarcon, 49, Villafranca del Castillo, 28692 Spain
| |
Collapse
|
83
|
Parrilla M, Cánovas R, Jeerapan I, Andrade FJ, Wang J. A Textile-Based Stretchable Multi-Ion Potentiometric Sensor. Adv Healthc Mater 2016; 5:996-1001. [PMID: 26959998 DOI: 10.1002/adhm.201600092] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Indexed: 11/11/2022]
Abstract
A textile-based wearable multi-ion potentiometric sensor array is described. The printed flexible sensors operate favorably under extreme mechanical strains (that reflect daily activity) while offering attractive real-time noninvasive monitoring of electrolytes such as sodium and potassium.
Collapse
Affiliation(s)
- Marc Parrilla
- Department of NanoEngineering; University of California; San Diego, La Jolla CA 92093 USA
| | - Rocío Cánovas
- Department of NanoEngineering; University of California; San Diego, La Jolla CA 92093 USA
| | - Itthipon Jeerapan
- Department of NanoEngineering; University of California; San Diego, La Jolla CA 92093 USA
| | - Francisco J. Andrade
- Departament de Química Analítica i Química Orgànica; Universitat Rovira i Virgili; C/Marcel·lí Domingo 1 Tarragona 43007 Spain
| | - Joseph Wang
- Department of NanoEngineering; University of California; San Diego, La Jolla CA 92093 USA
| |
Collapse
|
84
|
Parrilla M, Ferré J, Guinovart T, Andrade FJ. Wearable Potentiometric Sensors Based on Commercial Carbon Fibres for Monitoring Sodium in Sweat. ELECTROANAL 2016. [DOI: 10.1002/elan.201600070] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
85
|
Davis JK, Baker LB, Barnes K, Ungaro C, Stofan J. Thermoregulation, Fluid Balance, and Sweat Losses in American Football Players. Sports Med 2016; 46:1391-405. [DOI: 10.1007/s40279-016-0527-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
86
|
Matzeu G, Fay C, Vaillant A, Coyle S, Diamond D. A Wearable Device for Monitoring Sweat Rates via Image Analysis. IEEE Trans Biomed Eng 2015; 63:1672-80. [PMID: 26394409 DOI: 10.1109/tbme.2015.2477676] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A feasibility study on a new technique capable of monitoring localized sweat rate is explored in this paper. Wearable devices commonly used in clinical practice for sweat sampling (i.e., Macroducts) were positioned on the body of an athlete whose sweat rate was then monitored during cycling sessions. The position at which the sweat fills the Macroduct was indicated by a contrasting marker and captured via a series of time-stamped photos or a video recording of the device during an exercise period. Given that the time of each captured image/frame is known (either through time stamp on photos or the constant frame rate of the video capture), it was, therefore, possible to estimate the sweat flow rate through a simple calibration model. The importance of gathering such valuable information is described, together with the results from a number of exercise trials to investigate the viability of this approach.
Collapse
|
87
|
Miller KC. Electrolyte and plasma responses after pickle juice, mustard, and deionized water ingestion in dehydrated humans. J Athl Train 2015; 49:360-7. [PMID: 24955622 DOI: 10.4085/1062-6050-49.2.23] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Some athletes ingest pickle juice (PJ) or mustard to treat exercise-associated muscle cramps (EAMCs). Clinicians warn against this because they are concerned it will exacerbate exercise-induced hypertonicity or cause hyperkalemia. Few researchers have examined plasma responses after PJ or mustard ingestion in dehydrated, exercised individuals. OBJECTIVE To determine if ingesting PJ, mustard, or deionized water (DIW) while hypohydrated affects plasma sodium (Na(+)) concentration ([Na(+)]p), plasma potassium (K(+)) concentration ([K(+)]p), plasma osmolality (OSMp), or percentage changes in plasma volume or Na(+) content. DESIGN Crossover study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 9 physically active, nonacclimated individuals (age = 25 ± 2 years, height = 175.5 ± 9.0 cm, mass = 78.6 ± 13.8 kg). INTERVENTION(S) Participants exercised vigorously for 2 hours (temperature = 37°C ± 1°C, relative humidity = 24% ± 4%). After a 30-minute rest, a baseline blood sample was collected, and they ingested 1 mL/kg body mass of PJ or DIW. For the mustard trial, participants ingested a mass of mustard containing a similar amount of Na(+) as for the PJ trial. Postingestion blood samples were collected at 5, 15, 30, and 60 minutes. MAIN OUTCOME MEASURE(S) The dependent variables were [Na(+)]p, [K(+)]p, OSMp, and percentage change in plasma Na(+) content and plasma volume. RESULTS Participants became 2.9% ± 0.6% hypohydrated and lost 96.8 ± 27.1 mmol (conventional unit = 96.8 ± 27.1 mEq) of Na(+), 8.4 ± 2 mmol (conventional unit = 8.4 ± 2 mEq) of K(+), and 2.03 ± 0.44 L of fluid due to exercise-induced sweating. They ingested approximately 79 mL of PJ or DIW or 135.24 ± 22.8 g of mustard. Despite ingesting approximately 1.5 g of Na(+) in the PJ and mustard trials, no changes occurred within 60 minutes postingestion for [Na(+)]p, [K(+)]p, OSMp, or percentage changes in plasma volume or Na(+) content (P > .05). CONCLUSIONS Ingesting a small bolus of PJ or large mass of mustard after dehydration did not exacerbate exercise-induced hypertonicity or cause hyperkalemia. Consuming small volumes of PJ or mustard did not fully replenish electrolytes and fluid losses. Additional research on plasma responses pre-ingestion and postingestion to these treatments in individuals experiencing acute EAMCs is needed.
Collapse
Affiliation(s)
- Kevin C Miller
- School of Rehabilitation and Medical Science, Central Michigan University, Mount Pleasant
| |
Collapse
|
88
|
Baker LB, Barnes KA, Anderson ML, Passe DH, Stofan JR. Normative data for regional sweat sodium concentration and whole-body sweating rate in athletes. J Sports Sci 2015; 34:358-68. [DOI: 10.1080/02640414.2015.1055291] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
89
|
Schlader ZJ, Ganio MS, Pearson J, Lucas RAI, Gagnon D, Rivas E, Kowalske KJ, Crandall CG. Heat acclimation improves heat exercise tolerance and heat dissipation in individuals with extensive skin grafts. J Appl Physiol (1985) 2015; 119:69-76. [PMID: 25930025 DOI: 10.1152/japplphysiol.00176.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/23/2015] [Indexed: 11/22/2022] Open
Abstract
Burn survivors with extensive skin grafts have impaired heat dissipation and thus heat tolerance. This study tested the hypothesis that heat acclimation (HA) improves these factors in this population. Thirty-four burn survivors were stratified into highly [>40% body surface area (BSA) grafted, n = 15] and moderately (17-40% BSA grafted, n = 19) grafted groups. Nine healthy nonburned subjects served as controls. Subjects underwent 7 days of HA involving 90 min of exercise at ∼ 50% peak oxygen uptake in 40°C, 30% relative humidity. On days 1 and 7, subjects exercised in the heat at a fixed rate of metabolic heat production. Pre-HA, all controls and 18/19 subjects in the 17-40% group completed 90 min of exercise. Conversely, heat exercise tolerance was lower (P < 0.01) in the > 40% group, with 7/15 subjects not completing 90 min of exercise. Post-HA, heat exercise tolerance was similar between groups (P = 0.39) as all subjects, except one, completed 90 min of exercise. Pre-HA, the magnitude of the increase in internal temperature during exercise occurred sequentially (P ≤ 0.03) according to BSA grafted (>40%: 1.6 ± 0.5°C; 17-40%: 1.2 ± 0.3°C; control: 0.9 ± 0.2°C). HA attenuated (P < 0.01) increases in internal temperature in the control (by 0.2 ± 0.3°C), 17-40% (by 0.3 ± 0.3°C), and > 40% (by 0.3 ± 0.4°C) groups, the magnitude of which was similar between groups (P = 0.42). These data indicate that HA improves heat tolerance and dissipation in burn survivors with grafted skin, and the magnitude of these improvements are not influenced by the extent of skin grafting.
Collapse
Affiliation(s)
- Zachary J Schlader
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas and Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Matthew S Ganio
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas and Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, Arkansas
| | - James Pearson
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas and Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Biology, University of Colorado at Colorado Springs, Colorado
| | - Rebekah A I Lucas
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas and Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Daniel Gagnon
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas and Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Eric Rivas
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas and Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Kinesiology, Texas Woman's University, Denton, Texas; and
| | - Karen J Kowalske
- Department of Physical Medicine and Rehabilitation, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Craig G Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas and Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas;
| |
Collapse
|
90
|
Jones BL, O'Hara JP, Till K, King RF. Dehydration and Hyponatremia in Professional Rugby Union Players. J Strength Cond Res 2015; 29:107-15. [DOI: 10.1519/jsc.0000000000000620] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
91
|
|
92
|
Abstract
The objective of this article is to provide a review of the fundamental aspects of body fluid balance and the physiological consequences of water imbalances, as well as discuss considerations for the optimal composition of a fluid replacement beverage across a broad range of applications. Early pioneering research involving fluid replacement in persons suffering from diarrheal disease and in military, occupational, and athlete populations incurring exercise- and/or heat-induced sweat losses has provided much of the insight regarding basic principles on beverage palatability, voluntary fluid intake, fluid absorption, and fluid retention. We review this work and also discuss more recent advances in the understanding of fluid replacement as it applies to various populations (military, athletes, occupational, men, women, children, and older adults) and situations (pathophysiological factors, spaceflight, bed rest, long plane flights, heat stress, altitude/cold exposure, and recreational exercise). We discuss how beverage carbohydrate and electrolytes impact fluid replacement. We also discuss nutrients and compounds that are often included in fluid-replacement beverages to augment physiological functions unrelated to hydration, such as the provision of energy. The optimal composition of a fluid-replacement beverage depends upon the source of the fluid loss, whether from sweat, urine, respiration, or diarrhea/vomiting. It is also apparent that the optimal fluid-replacement beverage is one that is customized according to specific physiological needs, environmental conditions, desired benefits, and individual characteristics and taste preferences.
Collapse
|
93
|
Linseman ME, Palmer MS, Sprenger HM, Spriet LL. Maintaining hydration with a carbohydrate–electrolyte solution improves performance, thermoregulation, and fatigue during an ice hockey scrimmage. Appl Physiol Nutr Metab 2014; 39:1214-21. [DOI: 10.1139/apnm-2014-0091] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Research in “stop-and-go” sports has demonstrated that carbohydrate ingestion improves performance and fatigue, and that dehydration of ∼1.5%–2% body mass (BM) loss results in decreased performance, increased fatigue, and increased core temperature. The purpose of this investigation was to assess the physiological, performance, and fatigue-related effects of maintaining hydration with a carbohydrate–electrolyte solution (CES) versus dehydrating by ∼2% BM (no fluid; NF) during a 70-min ice hockey scrimmage. Skilled male hockey players (n = 14; age, 21.3 ± 0.2 years; BM, 80.1 ± 2.5 kg; height, 182.0 ± 1.2 cm) volunteered for the study. Subjects lost 1.94% ± 0.1% BM in NF, and 0.12% ± 0.1% BM in CES. Core temperature (Tc) throughout the scrimmage (10–50 min) and peak Tc (CES: 38.69 ± 0.10 vs. NF: 38.92 ± 0.11 °C; p < 0.05) were significantly reduced in CES compared with NF. Players in CES had increased mean skating speed and time at high effort between 30–50 min of the scrimmage. They also committed fewer puck turnovers and completed a higher percentage of passes in the last 20 min of play compared with NF. Postscrimmage shuttle skating performance was improved in CES versus NF and fatigue was lower following the CES trial. The results indicated that ingesting a CES to maintain BM throughout a 70-min hockey scrimmage resulted in improved hockey performance and thermoregulation, and decreased fatigue as compared with drinking no fluid and dehydrating by ∼2%.
Collapse
Affiliation(s)
- Mark E. Linseman
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Matthew S. Palmer
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Heather M. Sprenger
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Lawrence L. Spriet
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| |
Collapse
|
94
|
Hew-Butler T, Hummel J, Rider BC, Verbalis JG. Characterization of the effects of the vasopressin V2 receptor on sweating, fluid balance, and performance during exercise. Am J Physiol Regul Integr Comp Physiol 2014; 307:R366-75. [PMID: 24944242 DOI: 10.1152/ajpregu.00120.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A regulatory effect of arginine vasopressin (AVP) on sweat water conservation has been hypothesized but not definitively evaluated. AVP-mediated insertion of sweat and salivary gland aquaporin-5 (AQP5) water channels through activation of the vasopressin type 2 receptor (V2R) remains an attractive, yet unexplored, mechanism that could result in a more concentrated sweat with resultant decreased water loss. Ten runners participated in a double-blind randomized control treadmill trial under three separate pharmacological conditions: a placebo, V2R agonist (0.2 mg desmopressin), or V2R antagonist (30 mg tolvaptan). After a familiarization trial, runners ran for 60 min at 60% of peak speed followed by a performance trial to volitional exhaustion. Outcome variables were collected at three exercise time points: baseline, after the steady-state run, and after the performance run. Body weight losses were <2% across all three trials. Significant pharmacological condition effects were noted for urine osmolality [F = 84.98; P < 0.0001] and urine sodium concentration ([Na(+)]) [F = 38.9; P < 0.0001], which verified both pharmacological activation and inhibition of the V2R at the kidney collecting duct. Plasma osmolality and [Na(+)] demonstrated significant exercise (F = 26.0 and F = 11.1; P < 0.0001) and condition (F = 5.1 and F = 3.8; P < 0.05) effects (osmolality and [Na(+)], respectively). No significant exercise or condition effects were noted for either sweat or salivary [Na(+)]. Significant exercise effects were noted for plasma [AVP] (F = 22.3; P < 0.0001), peak core temperature (F = 103.3; P < 0.0001), percent body weight change (F = 6.3; P = 0.02), plasma volume change (F = 21.8; P < 0.0001), and thirst rating (F = 78.2; P < 0.0001). Performance time was not altered between conditions (P = 0.80). In summary, AVP acting at V2R does not appear to regulate water losses from body fluids other than renal excretion during exercise.
Collapse
Affiliation(s)
- Tamara Hew-Butler
- Exercise Science Program, Oakland University, Rochester, Michigan; and
| | - Jed Hummel
- Exercise Science Program, Oakland University, Rochester, Michigan; and
| | - Brian C Rider
- Exercise Science Program, Oakland University, Rochester, Michigan; and
| | - Joseph G Verbalis
- Endocrinology and Metabolism, Georgetown University Medical Center, Washington, DC
| |
Collapse
|
95
|
Baker LB, Ungaro CT, Barnes KA, Nuccio RP, Reimel AJ, Stofan JR. Validity and reliability of a field technique for sweat Na+ and K+ analysis during exercise in a hot-humid environment. Physiol Rep 2014; 2:e12007. [PMID: 24793982 PMCID: PMC4098735 DOI: 10.14814/phy2.12007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
This study compared a field versus reference laboratory technique for extracting (syringe vs. centrifuge) and analyzing sweat [Na+] and [K+] (compact Horiba B‐722 and B‐731, HORIBA vs. ion chromatography, HPLC) collected with regional absorbent patches during exercise in a hot‐humid environment. Sweat samples were collected from seven anatomical sites on 30 athletes during 1‐h cycling in a heat chamber (33°C, 67% rh). Ten minutes into exercise, skin was cleaned/dried and two sweat patches were applied per anatomical site. After removal, one patch per site was centrifuged and sweat was analyzed with HORIBA in the heat chamber (CENTRIFUGE HORIBA) versus HPLC (CENTRIFUGE HPLC). Sweat from the second patch per site was extracted using a 5‐mL syringe and analyzed with HORIBA in the heat chamber (SYRINGE HORIBA) versus HPLC (SYRINGE HPLC). CENTRIFUGE HORIBA, SYRINGE HPLC, and SYRINGE HORIBA were highly related to CENTRIFUGE HPLC ([Na+]: ICC = 0.96, 0.94, and 0.93, respectively; [K+]: ICC = 0.87, 0.92, and 0.84, respectively), while mean differences from CENTRIFUGE HPLC were small but usually significant ([Na+]: 4.7 ± 7.9 mEql/L, −2.5 ± 9.3 mEq/L, 4.0 ± 10.9 mEq/L (all P < 0.001), respectively; [K+]: 0.44 ± 0.52 mEq/L (P < 0.001), 0.01 ± 0.49 mEq/L (P = 0.77), 0.50 ± 0.48 mEq/L (P < 0.001), respectively). On the basis of typical error of the measurement results, sweat [Na+] and [K+] obtained with SYRINGE HORIBA falls within ±15.4 mEq/L and ±0.68 mEq/L, respectively, of CENTRIFUGE HPLC 95% of the time. The field (SYRINGE HORIBA) method of extracting and analyzing sweat from regional absorbent patches may be useful in obtaining sweat [Na+] when rapid estimates in a hot‐humid field setting are needed. This study compared a field versus reference laboratory technique for extracting (SYRINGE vs. CENTRIFUGE) and analyzing sweat [Na+] and [K+] (compact HORIBA B‐722 and B‐731 versus ion chromatography, HPLC) collected with regional absorbent patches during exercise in a hot‐humid environment. The HORIBA analyzers provided highly reliable test‐retest and day‐to‐day measurements of sweat [Na+] and [K+]. The 95% limit of agreement between the SYRINGE HORIBA field technique and the reference laboratory‐based CENTRIFUGE HPLC technique was ±15.4 mEq/L and ±0.68 mEq/L for [Na+] and [K+], respectively; which may be acceptable in a field‐testing context, when simply aiming to estimate electrolyte losses for the purpose of identifying athletes/workers at greater risk for large electrolyte losses.
Collapse
Affiliation(s)
- Lindsay B Baker
- Gatorade Sports Science Institute, Barrington, Illinois, USA
| | | | | | | | | | | |
Collapse
|
96
|
Cosgrove SD, Love TD, Brown RC, Baker DF, Howe AS, Black KE. Fluid and Electrolyte Balance During Two Different Preseason Training Sessions in Elite Rugby Union Players. J Strength Cond Res 2014; 28:520-7. [DOI: 10.1519/jsc.0b013e3182986d43] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
97
|
Variability of measurements of sweat sodium using the regional absorbent-patch method. Int J Sports Physiol Perform 2014; 9:832-8. [PMID: 24436351 DOI: 10.1123/ijspp.2013-0480] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
CONTEXT There is interest in including recommendations for the replacement of the sodium lost in sweat in individualized hydration plans for athletes. PURPOSE Although the regional absorbent-patch method provides a practical approach to measuring sweat sodium losses in field conditions, there is a need to understand the variability of estimates associated with this technique. METHODS Sweat samples were collected from the forearms, chest, scapula, and thigh of 12 cyclists during 2 standardized cycling time trials in the heat and 2 in temperate conditions. Single measure analysis of sodium concentration was conducted immediately by ion-selective electrodes (ISE). A subset of 30 samples was frozen for reanalysis of sodium concentration using ISE, flame photometry (FP), and conductivity (SC). RESULTS Sweat samples collected in hot conditions produced higher sweat sodium concentrations than those from the temperate environment (P = .0032). A significant difference (P = .0048) in estimates of sweat sodium concentration was evident when calculated from the forearm average (mean ± 95% CL; 64 ± 12 mmol/L) compared with using a 4-site equation (70 ± 12 mmol/L). There was a high correlation between the values produced using different analytical techniques (r2 = .95), but mean values were different between treatments (frozen FP, frozen SC > immediate ISE > frozen ISE; P < .0001). CONCLUSION Whole-body sweat sodium concentration estimates differed depending on the number of sites included in the calculation. Environmental testing conditions should be considered in the interpretation of results. The impact of sample freezing and subsequent analytical technique was small but statistically significant. Nevertheless, when undertaken using a standardized protocol, the regional absorbent-patch method appears to be a relatively robust field test.
Collapse
|
98
|
Goulet EDB, Dion T, Myette-Côté É. Validity and reliability of the Horiba C-122 compact sodium analyzer in sweat samples of athletes. Eur J Appl Physiol 2013; 112:3479-85. [PMID: 22294293 DOI: 10.1007/s00421-012-2331-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Accepted: 01/18/2012] [Indexed: 11/26/2022]
Abstract
Accurate sodium replacement during prolonged exercise is possible when sweat rate and sweat sodium content are directly measured. Few athletes have access to sweat sodium content measurement, as the equipment needed to perform such analyzes is costly, laboratory-based or requires technical skills. Using 70 sweat samples collected in 24 athletes from 3 anatomical sites, this study determined the reliability [single-trial and inter-day (7 samples over 3 days)] and validity (instrument error) of a pocket-sized, easy-to-use and low cost sodium analyzer (Horiba C-122, Kyoto, Japan) against reference values of an ion chromatograph, the 883 Basic IC plus (Metrohm AG, Herisau, Switzerland). The Horiba C-122 showed high single-trial reliability with an intraclass correlation coefficient (ICC) of 0.997, a typical error of measurement (EM) of 1.77 mmol/L and a coefficient of variation (CV) of 3.73%. As expected, the reliability of the 883 Basic IC plus was superior to that of the Horiba C-122 (ICC: 0.999; typical EM: 0.70 mmol/L; CV: 1.52%). The Horiba’s C-122 inter-day reliability was high (ICC: 1.00; typical EM: 0.35 mmol/L). An ICC of 0.975 indicates there was a strong relationship between results provided by both analyzers. Compared with reference values, the Horiba C-122 demonstrated a mean bias of 1.71 mmol/L, a pure EM of 7.52 mmol/L and 68% limits of agreement ranging from -5.81 to 9.23 mmol/L. We propose that the Horiba C-122 is sufficiently reliable to be used under field conditions where some degree of imprecision is acceptable, but not for research purposes where high accuracy is required.
Collapse
Affiliation(s)
- Eric D B Goulet
- Research Centre On Aging, University of Sherbrooke, 1036 Belvédère Sud, Sherbrooke, QC, J1H 4C4, Canada.
| | | | | |
Collapse
|
99
|
Taylor NA, Machado-Moreira CA. Regional variations in transepidermal water loss, eccrine sweat gland density, sweat secretion rates and electrolyte composition in resting and exercising humans. EXTREME PHYSIOLOGY & MEDICINE 2013; 2:4. [PMID: 23849497 PMCID: PMC3710196 DOI: 10.1186/2046-7648-2-4] [Citation(s) in RCA: 250] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 12/06/2012] [Indexed: 11/10/2022]
Abstract
Literature from the past 168 years has been filtered to provide a unified summary of the regional distribution of cutaneous water and electrolyte losses. The former occurs via transepidermal water vapour diffusion and secretion from the eccrine sweat glands. Daily insensible water losses for a standardised individual (surface area 1.8 m2) will be 0.6-2.3 L, with the hands (80-160 g.h-1) and feet (50-150 g.h-1) losing the most, the head and neck losing intermediate amounts (40-75 g.h-1) and all remaining sites losing 15-60 g.h-1. Whilst sweat gland densities vary widely across the skin surface, this same individual would possess some 2.03 million functional glands, with the highest density on the volar surfaces of the fingers (530 glands.cm-2) and the lowest on the upper lip (16 glands.cm-2). During passive heating that results in a resting whole-body sweat rate of approximately 0.4 L.min-1, the forehead (0.99 mg.cm-2.min-1), dorsal fingers (0.62 mg.cm-2.min-1) and upper back (0.59 mg.cm-2.min-1) would display the highest sweat flows, whilst the medial thighs and anterior legs will secrete the least (both 0.12 mg.cm-2.min-1). Since sweat glands selectively reabsorb electrolytes, the sodium and chloride composition of discharged sweat varies with secretion rate. Across whole-body sweat rates from 0.72 to 3.65 mg.cm-2.min-1, sodium losses of 26.5-49.7 mmol.L-1 could be expected, with the corresponding chloride loss being 26.8-36.7 mmol.L-1. Nevertheless, there can be threefold differences in electrolyte losses across skin regions. When exercising in the heat, local sweat rates increase dramatically, with regional glandular flows becoming more homogeneous. However, intra-regional evaporative potential remains proportional to each local surface area. Thus, there is little evidence that regional sudomotor variations reflect an hierarchical distribution of sweating either at rest or during exercise.
Collapse
Affiliation(s)
- Nigel As Taylor
- Centre for Human and Applied Physiology, School of Health Sciences, University of Wollongong, Wollongong, New South Wales, 2522, Australia.
| | | |
Collapse
|
100
|
Kamijo YI, Ikegawa S, Okada Y, Masuki S, Okazaki K, Uchida K, Sakurai M, Nose H. Enhanced renal Na+ reabsorption by carbohydrate in beverages during restitution from thermal and exercise-induced dehydration in men. Am J Physiol Regul Integr Comp Physiol 2012; 303:R824-33. [PMID: 22874424 DOI: 10.1152/ajpregu.00588.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined whether carbohydrate in beverages accelerated fluid retention during recovery from thermal and exercise-induced dehydration and whether it was caused in part by an enhanced renal Na+ reabsorption rate due to insulin secretion. After dehydrating by ∼2.3% body weight by exercise in a hot environment, seven young men underwent high-carbohydrate, low-carbohydrate, or control rehydration trials by drinking one of three beverages with 3.4 g glucose + 3.1 g fructose, 1.7 g glucose + 1.6 g fructose, or 0.0 g glucose + 0.0 g fructose per deciliter, respectively, in a common composition of electrolyte solution: 21 meq/l [Na+], 5 meq/l [K+], 16.5 meq/l [Cl-], 10 meq/l [citrate(-3)]. They drank the same amount of beverage as total body weight loss within 30 min. During the 60 min before the start of drinking and the following 180 min, we measured plasma volume (PV), plasma glucose ([Glc]p), serum insulin ([Ins]s), plasma Na+ concentrations, and the renal clearances of inulin, lithium, and Na+ with plasma vasopressin ([AVP]p) and aldosterone concentrations ([Ald]p) every 30 min. After dehydration, PV decreased by ∼5% and plasma osmolality increased by ∼6 mosmol/kg H2O in all trials with no significant differences among them. We found in the high-carbohydrate trial that 1) PV increased faster than in the control trial and remained at the higher level than other trials for the last 60 min (P < 0.05); 2) accumulated urine volume was smallest after 90 min (P < 0.05); 3) the renal Na+ reabsorption rate was greatest for the first 120 min (P < 0.05); 4) during which period [AVP]p and [Ald](p) were not significantly different from other trials (both, P > 0.9); and 5) [Glc](p) and [Ins]s were highest from 45 to 105 min (P < 0.05) during rehydration. Thus carbohydrate in beverages enhances renal Na+ reabsorption, and insulin is possibly involved in this enhancement.
Collapse
Affiliation(s)
- Yoshi-Ichiro Kamijo
- Dept. of Sports Medical Sciences, Institute of Pathogenesis and Disease Prevention, Shinshu Univ. Graduate School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan
| | | | | | | | | | | | | | | |
Collapse
|