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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 -
Autonomic Neuroscience : Basic &... Apr 2016This review examines the cardiovascular adaptations along with total body water and plasma volume adjustments that occur in parallel with improved heat loss responses... (Review)
Review
This review examines the cardiovascular adaptations along with total body water and plasma volume adjustments that occur in parallel with improved heat loss responses during exercise-heat acclimation. The cardiovascular system is well recognized as an important contributor to exercise-heat acclimation that acts to minimize physiological strain, reduce the risk of serious heat illness and better sustain exercise capacity. The upright posture adopted by humans during most physical activities and the large skin surface area contribute to the circulatory and blood pressure regulation challenge of simultaneously supporting skeletal muscle blood flow and dissipating heat via increased skin blood flow and sweat secretion during exercise-heat stress. Although it was traditionally held that cardiac output increased during exercise-heat stress to primarily support elevated skin blood flow requirements, recent evidence suggests that temperature-sensitive mechanisms may also mediate an elevation in skeletal muscle blood flow. The cardiovascular adaptations supporting this challenge include an increase in total body water, plasma volume expansion, better sustainment and/or elevation of stroke volume, reduction in heart rate, improvement in ventricular filling and myocardial efficiency, and enhanced skin blood flow and sweating responses. The magnitude of these adaptations is variable and dependent on several factors such as exercise intensity, duration of exposure, frequency and total number of exposures, as well as the environmental conditions (i.e. dry or humid heat) in which acclimation occurs.
Topics: Acclimatization; Adaptation, Physiological; Animals; Exercise; Heat Stress Disorders; Hot Temperature; Humans; Sweating
PubMed: 26905458
DOI: 10.1016/j.autneu.2016.02.002 -
American Family Physician Oct 2020Night sweats are a nonspecific symptom that patients commonly experience but rarely discuss with their physicians without prompting. Although many life-threatening... (Review)
Review
Night sweats are a nonspecific symptom that patients commonly experience but rarely discuss with their physicians without prompting. Although many life-threatening causes such as malignancies or infections have been described, most patients who report persistent night sweats in the primary care setting do not have a serious underlying disorder. Conditions commonly associated with night sweats include menopause, mood disorders, gastroesophageal reflux disease, hyperthyroidism, and obesity. If a clinical diagnosis is apparent based on the initial history and physical examination, specific treatment for four to eight weeks may be offered. When the history and physical examination do not reveal a specific cause, physicians should proceed with a systematic and cost-conscious strategy that uses readily available laboratory and imaging studies, such as a complete blood count, tuberculosis testing, thyroid-stimulating hormone levels, HIV testing, C-reactive protein level, and chest radiography. Additional tests that could be considered selectively include computed tomography of the chest and/or abdomen, bone marrow biopsy, polysomnography, and/or additional laboratory studies if indicated. If these results are normal, and no additional disorders are suspected, reassurance and continued monitoring are recommended. The presence of night sweats alone does not indicate an increased risk of death.
Topics: Circadian Rhythm; Humans; Sweating
PubMed: 32996756
DOI: No ID Found -
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 -
American Journal of Clinical Dermatology Jan 2023Cholinergic urticaria (CholU) is a subtype of chronic inducible urticaria with a chief complaint of itching and/or stinging, painful papular wheals that develop... (Review)
Review
Cholinergic urticaria (CholU) is a subtype of chronic inducible urticaria with a chief complaint of itching and/or stinging, painful papular wheals that develop simultaneously with sweating. This review specifically focuses on several subtypes of CholU and specifically investigates the relationship between CholU and anhidrosis. We review recent publications and update the evidence around CholU, including the epidemiology, clinical features, diagnostic approaches, physiopathology, subtype classification, and therapeutic approaches. Multiple mechanisms contribute in a complex manner to the development of CholU, including histamine, sweat allergy, cholinergic-related substances, poral occlusion, and hypohidrosis/anhidrosis. A new schematic of the currently known pathological conditions has been created. Specific methods for diagnosing CholU, a provocation test, and evaluation methods for disease severity/activity and disease burden of CholU are summarized. The characteristics of the diseases that should be differentiated from CholU and examination methods are also summarized. The primary finding of this review is that CholU should be categorized based on the etiology and clinical characteristics of each subtype to properly manage and treat the disease. This categorization leads to improvement of therapeutic resistance status of this disease. In particular, a sweating abnormality should be given more attention when examining patients with CholU. Because CholU is not a homogeneous disease, its subtype classification is important for selection of the most suitable therapeutic method. Further elucidation of the pathophysiology of each subtype is expected.
Topics: Humans; Hypohidrosis; Urticaria; Sweating; Sweat; Cholinergic Agents
PubMed: 36107396
DOI: 10.1007/s40257-022-00728-6 -
Journal of Athletic Training Sep 2017To present evidence-based recommendations that promote optimized fluid-maintenance practices for physically active individuals.
OBJECTIVE
To present evidence-based recommendations that promote optimized fluid-maintenance practices for physically active individuals.
BACKGROUND
Both a lack of adequate fluid replacement (hypohydration) and excessive intake (hyperhydration) can compromise athletic performance and increase health risks. Athletes need access to water to prevent hypohydration during physical activity but must be aware of the risks of overdrinking and hyponatremia. Drinking behavior can be modified by education, accessibility, experience, and palatability. This statement updates practical recommendations regarding fluid-replacement strategies for physically active individuals.
RECOMMENDATIONS
Educate physically active people regarding the benefits of fluid replacement to promote performance and safety and the potential risks of both hypohydration and hyperhydration on health and physical performance. Quantify sweat rates for physically active individuals during exercise in various environments. Work with individuals to develop fluid-replacement practices that promote sufficient but not excessive hydration before, during, and after physical activity.
Topics: Athletic Performance; Dehydration; Drinking; Evidence-Based Medicine; Exercise; Fluid Therapy; Humans; Sports; Sweat; Sweating; Water; Water-Electrolyte Balance
PubMed: 28985128
DOI: 10.4085/1062-6050-52.9.02 -
Journal of the International Society of... Jun 2018Athletes commonly consume insufficient fluid and electrolytes just prior to, or during training and competition. Unlike non-athletes or athletes who do not engage in... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Athletes commonly consume insufficient fluid and electrolytes just prior to, or during training and competition. Unlike non-athletes or athletes who do not engage in frequent rigorous and prolonged training sessions, "hard trainers" may require additional sodium and better benefit from a hydration plan tailored to their individual physiology. The purpose of this randomized cross-over study was to determine whether a hydration plan based off of an athlete's sweat rate and sodium loss improves anaerobic and neurocognitive performance during a moderate to hard training session as well as heart rate recovery from this session.
METHODS
Collegiate athletes who were injury free and could exercise at ≥ 75% of their maximum heart rate for a minimum of 45 min were recruited for this randomized, cross-over study. After completing a questionnaire assessing hydration habits, participants were randomized either to a prescription hydration plan (PHP), which considered sweat rate and sodium loss or instructed to follow their normal ad libitum hydration habits (NHP) during training. Attention and awareness, as well as lower body anaerobic power (standing long jump) were assessed immediately before and after a moderate to hard training session of ≥ 45 min. Heart rate recovery was also measured. After a washout period of 7 days, the PHP group repeated the training bout with their normal hydration routine, while the NHP group were provided with a PHP plan and were assessed as previously described.
RESULTS
Fifteen athletes from three different sports, aged 20 ± 0.85 years, participated in this study. Most participants reported feeling somewhat or very dehydrated after a typical training session. Compared to their NHP, participants following a PHP jumped 4.53 ± 3.80 in. farther, tracked moving objects 0.36 ± 0.60 m/second faster, and exhibited a faster heart rate recovery following a moderate to hard training session of 45-120 min in duration.
CONCLUSION
A tailored hydration plan, based on an athlete's fluid and sodium loss has the potential to improve anaerobic power, attention and awareness, and heart rate recovery time.
Topics: Athletes; Athletic Performance; Attention; Awareness; Cross-Over Studies; Drinking; Female; Heart Rate; Humans; Male; Mental Status and Dementia Tests; Sodium; Sports Nutritional Physiological Phenomena; Sweat; Sweating; Water; Water-Electrolyte Balance; Young Adult
PubMed: 29866199
DOI: 10.1186/s12970-018-0230-2 -
The Journal of Physiological Sciences :... Aug 2021Sweat is a noninvasive biological fluid on the surface of human skin and has attracted increasing attention as a diagnostic specimen for disease and biomarker detection.... (Review)
Review
Sweat is a noninvasive biological fluid on the surface of human skin and has attracted increasing attention as a diagnostic specimen for disease and biomarker detection. Sweat metabolite quantification is possible due to progress in sweat analysis techniques; nevertheless, the role of sweat monitoring in energy metabolism, physiological or pathological state assessment, health status assessment, and the development and outcome of metabolism-related diseases remains unclear. This review provides a comprehensive overview of the literature on human sweat lactate concentration. The first, second, and third sections of this review present an introduction of sweat lactate, methods for the collection and storage of sweat lactate samples, and methods of detection and analysis of sweat lactate, respectively. The fourth section elaborates upon the current state of clinical application of sweat lactate monitoring and its prospects for health surveillance. The last section focuses on the challenges and future directions of this novel technology for detecting lactate in sweat.
Topics: Biosensing Techniques; Humans; Lactic Acid; Skin; Sweat; Sweating
PubMed: 34445952
DOI: 10.1186/s12576-021-00811-3 -
International Journal of Cosmetic... Aug 2023Sweating is the human body's thermoregulation system but also results in unpleasant body odour which can diminish the self-confidence of people. There has been continued... (Review)
Review
Sweating is the human body's thermoregulation system but also results in unpleasant body odour which can diminish the self-confidence of people. There has been continued research in finding solutions to reduce both sweating and body odour. Sweating is a result of increased sweat flow and malodour results from certain bacteria and ecological factors such as eating habits. Research on deodorant development focuses on inhibiting the growth of malodour-forming bacteria using antimicrobial agents, whereas research on antiperspirant synthesis focuses on technologies reducing the sweat flow, which not only reduces body odour but also improves people's appearance. Antiperspirant's technology is based on the use of aluminium salts which can form a gel plug at sweat pores, obstructing the sweat fluid from arising onto the skin surface. In this paper, we perform a systematic review on the recent progress in the development of novel antiperspirant and deodorant active ingredients that are alcohol-free, paraben-free, and naturally derived. Several studies have been reported on the alternative class of actives that can potentially be used for antiperspirant and body odour treatment including deodorizing fabric, bacterial, and plant extracts. However, a significant challenge is to understand how the gel-plugs of antiperspirant actives are formed in sweat pores and how to deliver long-lasting antiperspirant and deodorant benefits.
Topics: Humans; Antiperspirants; Deodorants; Body Odor; Sweating; Sweat Glands
PubMed: 36896776
DOI: 10.1111/ics.12852 -
Sensors (Basel, Switzerland) Oct 2019This review summarizes the latest developments in the field of skin chemical sensors, in particular wearable ones. Five major applications are covered in the present... (Review)
Review
This review summarizes the latest developments in the field of skin chemical sensors, in particular wearable ones. Five major applications are covered in the present work: (i) sweat analysis, (ii) skin hydration, (iii) skin wounds, (iv) perspiration of volatile organic compounds, and (v) general skin conditions. For each application, the detection of the most relevant analytes is described in terms of transduction principles and sensor performances. Special attention is paid to the biological fluid collection and storage and devices are also analyzed in terms of reusability and lifetime. This review highlights the existing gaps between current performances and those needed to promote effective commercialization of sensors; future developments are also proposed.
Topics: Humans; Sensation; Skin; Sweat; Volatile Organic Compounds; Wearable Electronic Devices
PubMed: 31658706
DOI: 10.3390/s19204376