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Sports Medicine (Auckland, N.Z.) Mar 2017Athletes 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... (Review)
Review
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.
Topics: Athletes; Exercise; Humans; Sodium; Sports; Sweat; Sweating; Water-Electrolyte Balance
PubMed: 28332116
DOI: 10.1007/s40279-017-0691-5 -
ACS Sensors Mar 2021Circadian dysfunction or dysregulation is associated with many chronic morbidities. Current state-of-art technologies do not provide an accurate estimation of the extent... (Review)
Review
Circadian dysfunction or dysregulation is associated with many chronic morbidities. Current state-of-art technologies do not provide an accurate estimation of the extent of disease affliction. Recent advances call for using wearables for improving management and diagnosis of circadian related disorders. Sweat contains an abundance of relevant biomarkers like cortisol, DHEA, and so forth, which could be leveraged toward tracking the user's chronobiology. In this article, we provide a review of the key developments in the field of wearable sensors for circadian technologies. We highlight the value of using sweat along with portable electronics toward developing state-of-the-art platforms for efficient diagnosis and management of chronic conditions. Finally, we discuss challenges and opportunities for using wearable sweat sensors for circadian diagnosis and disease management.
Topics: Biosensing Techniques; Circadian Rhythm; Sweat; Sweating; Wearable Electronic Devices
PubMed: 33645964
DOI: 10.1021/acssensors.0c02622 -
Journal of Science and Medicine in Sport Nov 2019
Topics: Humans; Sweat; Sweating; Tattooing
PubMed: 31431341
DOI: 10.1016/j.jsams.2019.08.001 -
The Journal of Thoracic and... Nov 2019
Topics: Humans; Hyperhidrosis; Sweat; Sweating; Sympathectomy; Thoracic Surgical Procedures
PubMed: 31623816
DOI: 10.1016/j.jtcvs.2019.08.035 -
Current Problems in Dermatology 2011While sweat is thought to be one of the important factors provoking exacerbations of clinical symptoms in atopic dermatitis (AD), little attention has been drawn to a... (Review)
Review
While sweat is thought to be one of the important factors provoking exacerbations of clinical symptoms in atopic dermatitis (AD), little attention has been drawn to a beneficial role of sweat in the development of AD lesions. However, if the permeability barrier and antimicrobial barrier dysfunction represents the primary event in the development of AD, an evaluation of sweating responses in AD is a logical place to look for changes that predispose to the disease. In this regard, there have been conflicting data regarding whether sweating responses are impaired, normal or enhanced in AD patients. Consistent with the results of most recent studies, our recent study showed that most AD patients exhibit a defective ability to deliver sweat to the skin surface in response to thermal stress. Despite such defective sweating responses observed in the most part, a marked augmentation in the sweating response with delayed kinetics can be paradoxically detected in some sweating glands of these AD patients, indicating compensatory hyperhidrosis. Dermcidin, a new antimicrobial peptide exclusively produced by sweat glands, was abundantly detected not only in the sweat glands and ducts, and the lumen, but also in the dermal tissues adjacent to the sweat glands. These results indicate that the sweat may be retained in the lumen or pour into the dermal tissues, thereby causing inflammation. Thus, chronic inflammation in AD may be caused in part by a dysfunction of the sweat delivery system.
Topics: Dermatitis, Atopic; Hot Temperature; Humans; Peptides; Skin Temperature; Stress, Physiological; Sweat; Sweat Glands; Sweating
PubMed: 21576948
DOI: 10.1159/000323297 -
The Veterinary Clinics of North... Apr 1998In the horse, sweat is produced by apocrine glands which are present over most haired and nonhaired skin. Although sweat secretion is initiated under a number of... (Review)
Review
In the horse, sweat is produced by apocrine glands which are present over most haired and nonhaired skin. Although sweat secretion is initiated under a number of circumstances, the central drive for sweating in response to a thermal stimulus is the primary mechanism for its production. Sweating is an essential and primary mechanism for heat dissipation during exercise or exposure to hot ambient conditions. The rate of sweat production will reflect the interaction of numerous factors, including exercise intensity, ambient conditions, state of hydration, and the training or heat acclimation status of the individual horse. Thus, the sweating rates produced in response to an exercise-induced thermal load can be further increased by high ambient temperature or humidity which reduces evaporative efficiency, thereby contributing to the rate of rise in core body temperature. Equine sweat is an isotonic to slightly hypertonic secretion with sodium, chloride, and potassium contributing the major ionic components. The ionic composition of equine sweat is largely rate dependent and therefore is affected by factors such as ambient conditions and exercise intensity which result in elevations in sodium concentration in response to increases in sweating rate. Large sweat fluid losses associated with prolonged exercise will incur significant ion deficits, leading to alterations in skeletal muscle ion content and the potential for muscular dysfunction. With respect to exercise performance, however, the more important consequence of sweat fluid losses is the impairment of temperature regulation that accompanies severe dehydration. Although it is advantageous to restore a proportion of the fluid and ion losses incurred during prolonged exercise, few strategies will fully and safely replace the electrolyte losses incurred. Nevertheless, daily electrolyte supplementation of a good-quality diet will provide an effective method of replacing sweat ion losses during training and competition under most ambient conditions.
Topics: Animals; Electrolytes; Fluid Therapy; Horses; Physical Conditioning, Animal; Sweat; Sweating; Water-Electrolyte Balance
PubMed: 9561689
DOI: 10.1016/s0749-0739(17)30213-4 -
Current Problems in Dermatology 2016The evaluation of sweating activities contributes to both medical services and social living. There are several old and new approaches for assessing sweating. These... (Review)
Review
The evaluation of sweating activities contributes to both medical services and social living. There are several old and new approaches for assessing sweating. These methods are mainly composed of adopted techniques that focus on detecting small amounts of water on the skin surface. For many years, the iodine-starch reaction has been applied in various settings to evaluate sweat on the skin surface. However, methodology based on the coloration of sweat is in a constant state of evolution, and multiple advancements have been made. Furthermore, common fingerprinting is not just used for obtaining personal-identifying information anymore as it can also provide scientifically important information for sweat-pore mapping and sweat-component analysis. Additionally, there are multiple techniques for the quantitative measurement of sweat volume and dynamic intravital imaging of sweat, and these are also continually evolving. This chapter provides an overview of the old and new approaches for assessing sweating.
Topics: Galvanic Skin Response; Humans; Microscopy, Fluorescence; Specimen Handling; Sweat; Sweat Gland Diseases; Sweat Glands; Sweating; Tomography, Optical Coherence
PubMed: 27584959
DOI: 10.1159/000446755 -
Glycobiology Mar 2016There is increasing evidence that secretory fluids such as tears, saliva and milk play an important role in protecting the human body from infection via a washing... (Review)
Review
There is increasing evidence that secretory fluids such as tears, saliva and milk play an important role in protecting the human body from infection via a washing mechanism involving glycan-mediated adhesion of potential pathogens to secretory glycoproteins. Interaction of sweat with bacteria is well established as the cause of sweat-associated malodor. However, the role of sweat glycoproteins in microbial attachment has received little, if any, research interest in the past. In this review, we demonstrate how recent published studies involving high-throughput proteomic analysis have inadvertently, and fortuitously, exposed an abundance of glycoproteins in sweat, many of which have also been identified in other secretory fluids. We bring together research demonstrating microbial adhesion to these secretory glycoproteins in tears, saliva and milk and suggest a similar role of the sweat glycoproteins in mediating microbial attachment to sweat and/or skin. The contribution of glycan-mediated microbial adhesion to sweat glycoproteins, and the associated impact on sweat derived malodor and pathogenic skin infections are unchartered new research areas that we are beginning to explore.
Topics: Bacteria; Bacterial Adhesion; Glycoproteins; Humans; Infections; Odorants; Polysaccharides; Sweat; Sweating
PubMed: 26582610
DOI: 10.1093/glycob/cwv102 -
The British Journal of Dermatology Apr 1973
Review
Topics: Acetylcholine; Animals; Animals, Domestic; Behavior, Animal; Body Temperature Regulation; Chlorides; Epinephrine; Humans; Mammals; Potassium; Skin Physiological Phenomena; Sodium; Sweat; Sweat Glands; Sweating
PubMed: 4582049
DOI: 10.1111/j.1365-2133.1973.tb07573.x -
European Journal of Applied Physiology Apr 2020The 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... (Review)
Review
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.
Topics: Acclimatization; Eccrine Glands; Electrolytes; Humans; Micronutrients; Physical Conditioning, Human; Sodium Chloride, Dietary; Specimen Handling; Sweat; Sweating
PubMed: 32124007
DOI: 10.1007/s00421-020-04323-7