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Journal of Sports Science & Medicine Sep 2021Sweating during exercise is regulated by objective parameters, body weight, and endothelial function, among other factors. However, the relationship between vascular... (Observational Study)
Observational Study
Sweating during exercise is regulated by objective parameters, body weight, and endothelial function, among other factors. However, the relationship between vascular arterial stiffness and sweat volume in young adults remains unclear. This study aimed to identify hemodynamic parameters before exercise that can predict sweat volume during exercise, and post-exercise parameters that can be predicted by the sweat volume. Eighty-nine young healthy subjects (aged 21.9 ± 1.7 years, 51 males) were recruited to each perform a 3-km run on a treadmill. Demographic and anthropometric data were collected and hemodynamic data were obtained, including heart rate, blood pressure and pulse wave analysis using non-invasive tonometry. Sweat volume was defined as pre-exercise body weight minus post-exercise body weight. Post-exercise hemodynamic parameters were also collected. Sweat volume was significantly associated with gender, body surface area (BSA) (b = 0.288, p = 0.010), peripheral systolic blood pressure (SBP), peripheral and central pulse pressure (PP), and was inversely associated with augmentation index at an HR of 75 beats/min (AIx@HR75) (b = -0.005, p = 0.019) and ejection duration. While BSA appeared to predict central PP (B = 19.271, p ≤ 0.001), central PP plus AIx@HR75 further predicted sweat volume (B = 0.008, p = 0.025; B = -0.009, p = 0.003 respectively). Sweat volume was associated with peripheral SBP change (B = -17.560, p = 0.031). Sweat volume during a 3-km run appears to be influenced by hemodynamic parameters, including vascular arterial stiffness and central pulse pressure. Results of the present study suggest that vascular arterial stiffness likely regulates sweat volume during exercise.
Topics: Blood Pressure; Body Surface Area; Female; Heart Rate; Hemodynamics; Humans; Male; Prospective Studies; Running; Sex Factors; Stroke Volume; Sweat; Sweating; Vascular Stiffness; Young Adult
PubMed: 34267584
DOI: 10.52082/jssm.2021.448 -
Nature Communications Nov 2022Sensory neurons generate spike patterns upon receiving external stimuli and encode key information to the spike patterns, enabling energy-efficient external information...
Sensory neurons generate spike patterns upon receiving external stimuli and encode key information to the spike patterns, enabling energy-efficient external information processing. Herein, we report an epifluidic electronic patch with spiking sweat clearance using a sensor containing a vertical sweat-collecting channel for event-driven, energy-efficient, long-term wireless monitoring of epidermal perspiration dynamics. Our sweat sensor contains nanomesh electrodes on its inner wall of the channel and unique sweat-clearing structures. During perspiration, repeated filling and abrupt emptying of the vertical sweat-collecting channel generate electrical spike patterns with the sweat rate and ionic conductivity proportional to the spike frequency and amplitude over a wide dynamic range and long time (> 8 h). With such 'spiking' sweat clearance and corresponding electronic spike patterns, the epifluidic wireless patch successfully decodes epidermal perspiration dynamics in an event-driven manner at different skin locations during exercise, consuming less than 0.6% of the energy required for continuous data transmission. Our patch could integrate various on-skin sensors and emerging edge computing technologies for energy-efficient, intelligent digital healthcare.
Topics: Sweat; Monitoring, Physiologic; Electrodes; Ions; Electronics; Biosensing Techniques
PubMed: 36344563
DOI: 10.1038/s41467-022-34442-y -
Clinical Autonomic Research : Official... Apr 2009Sudomotor dysfunction is common in many subtypes of neuropathy but is one of the earliest detectable neurophysiologic abnormalities in distal small fiber neuropathy.... (Review)
Review
Sudomotor dysfunction is common in many subtypes of neuropathy but is one of the earliest detectable neurophysiologic abnormalities in distal small fiber neuropathy. Clinical assessments of sudomotor function include thermoregulatory sweat testing (TST), quantitative sudomotor axon reflex testing (QSART), silicone impressions, the sympathetic skin response (SSR), the acetylcholine sweat-spot test and quantitative direct and indirect axon reflex testing (QDIRT). These testing techniques, when used in combination, can detect and localize pre- and postganglionic lesions, can provide early diagnosis of sudomotor dysfunction and can monitor disease progression or disease recovery. In this article, we describe many of the common clinical tests available for evaluation of sudomotor function with focus on the testing methodology and limitations while providing concrete examples of test results.
Topics: Acetylcholine; Diagnostic Techniques, Neurological; Humans; Peripheral Nervous System Diseases; Reflex; Sweat; Sweating
PubMed: 18989618
DOI: 10.1007/s10286-008-0506-8 -
The Journal of Physiological Sciences :... Nov 2012This review provides a critical overview of the literature published in the area of lactate in human sweat between 1934 and the present. The first section summarizes the... (Review)
Review
This review provides a critical overview of the literature published in the area of lactate in human sweat between 1934 and the present. The first section summarizes the relevant pieces of literature, the second evaluates the literature across a range of topics and the third presents potential applications for sweat lactate measurements. Key factors that may affect sweat lactate are discussed in detail in the second section of this review. Both acetylcholine and catecholamine hormonal signals can trigger sweating independently of one another; differences in sweat output and lactate concentrations are compared. The primary triggers for sweating, exercise and heat are also compared, with exercise-induced sweating being further examined with respect to the exercise intensity. This review examines the significant variations in sweat lactate between bodily sites as well the relationship to physiological parameters such as gender, age and physical fitness, along with the effect of climate adaptation on sweat lactate concentrations.
Topics: Adaptation, Physiological; Climate; Humans; Lactic Acid; Sweat; Sweating
PubMed: 22678934
DOI: 10.1007/s12576-012-0213-z -
Journal of Nanobiotechnology Nov 2023The rapid advancement of wearable biosensors has revolutionized healthcare monitoring by screening in a non-invasive and continuous manner. Among various sensing... (Review)
Review
The rapid advancement of wearable biosensors has revolutionized healthcare monitoring by screening in a non-invasive and continuous manner. Among various sensing techniques, field-effect transistor (FET)-based wearable biosensors attract increasing attention due to their advantages such as label-free detection, fast response, easy operation, and capability of integration. This review explores the innovative developments and applications of FET-based wearable biosensors for healthcare monitoring. Beginning with an introduction to the significance of wearable biosensors, the paper gives an overview of structural and operational principles of FETs, providing insights into their diverse classifications. Next, the paper discusses the fabrication methods, semiconductor surface modification techniques and gate surface functionalization strategies. This background lays the foundation for exploring specific FET-based biosensor designs, including enzyme, antibody and nanobody, aptamer, as well as ion-sensitive membrane sensors. Subsequently, the paper investigates the incorporation of FET-based biosensors in monitoring biomarkers present in physiological fluids such as sweat, tears, saliva, and skin interstitial fluid (ISF). Finally, we address challenges, technical issues, and opportunities related to FET-based biosensor applications. This comprehensive review underscores the transformative potential of FET-based wearable biosensors in healthcare monitoring. By offering a multidimensional perspective on device design, fabrication, functionalization and applications, this paper aims to serve as a valuable resource for researchers in the field of biosensing technology and personalized healthcare.
Topics: Biosensing Techniques; Sweat; Saliva; Biomarkers; Wearable Electronic Devices
PubMed: 37936115
DOI: 10.1186/s12951-023-02153-1 -
Nutrients Aug 2022This study examined sweat rate, sweat sodium concentration [Na], and ad-libitum carbohydrate and fluid intakes in elite female soccer players during training ( = 19) and...
This study examined sweat rate, sweat sodium concentration [Na], and ad-libitum carbohydrate and fluid intakes in elite female soccer players during training ( = 19) and a match ( = 8); eight completed both for comparisons. Body mass (kg) was obtained before and after exercise to calculate sweat rate. The sweat [Na] was determined from absorbent patches on the thigh or back. Sweat rate, percentage body mass change, and sweat [Na] for 19 players during training were 0.47 ± 0.19 L·h, +0.19 ± 0.65%, and 28 ± 10 mmol·L, respectively. Sweat rate was higher during a match (0.98 ± 0.34 L·h) versus training (0.49 ± 0.26 L·h, = 0.007). Body mass losses were greater post-match (-1.12 ± 0.86%) than training (+0.29 ± 0.34%, = 0.003). Sweat [Na] was similar for training (29 ± 9 mmol·L) and a match (35 ± 9 mmol·L) ( = 0.215). There were no differences in match versus training carbohydrate intakes (2.0 ± 2.3 g·h, 0.9 ± 1.5 g·h, respectively, = 0.219) or fluid intakes (0.71 ± 0.30 L·h, 0.53 ± 0.21 L·h, respectively, = 0.114). In conclusion, female soccer players' sweat rates were higher during a match than during training, and carbohydrate intakes were below recommendations for matches and training.
Topics: Carbohydrates; Dehydration; Female; Humans; Soccer; Sodium; Sweat; Sweating; Water-Electrolyte Balance
PubMed: 35956363
DOI: 10.3390/nu14153188 -
Journal of Applied Physiology... Aug 2018By combining galvanic skin conductance (GSC), stratum corneum hydration (HYD) and regional surface sweat rate (RSR) measurements at the arm, thigh, back and chest, we...
By combining galvanic skin conductance (GSC), stratum corneum hydration (HYD) and regional surface sweat rate (RSR) measurements at the arm, thigh, back and chest, we closely monitored the passage of sweat from gland to skin surface. Through a varied exercise-rest protocol, sweating was increased slowly and decreased in 16 male and female human participants (25.3 ± 4.7 yr, 174.6 ± 10.1 cm, 71.3 ± 12.0 kg, 53.0 ± 6.8 ml·kg·min). ∆GSC and HYD increased before RSR, indicating pre-secretory sweat gland activity and skin hydration. ∆GSC and HYD typically increased concomitantly during rest in a warm environment (30.1 ± 1.0°C, 30.0 ± 4.7% relative humidity) and only at the arm did ∆GSC increase before an increase in HYD. HYD increased before RSR, before sweat was visible on the skin, but not to full saturation, contradicting earlier hypotheses. Maximal skin hydration did occur, as demonstrated by a plateau in all regions. Post exercise rest resulted in a rapid decrease in HYD and RSR but a delayed decline in ∆GSC. Evidence for reabsorption of surface sweat into the skin following a decline in sweating, as hypothesized in the literature, was not found. This suggests that skin surface sweat, after sweating is decreased, may not diffuse back into the dermis, but is only evaporated. These data, showing distinctly different responses for the three measured variables, provide useful information about the fate of sweat from gland to surface that is relevant across numerous research fields (e.g., thermoregulation, dermatology, ergonomics and material design). NEW & NOTEWORTHY After sweat gland stimulation, sweat travels through the duct, penetrating the epidermis before appearing on the skin surface. We found that only submaximal stratum corneum hydration was required before surface sweating occurred. However, full hydration occurred only once sweat was on the surface. Once sweating reduces, surface sweat evaporation continues, but there is a delayed drying of the skin. This information is relevant across various research fields, including environmental ergonomics, dermatology, thermoregulation, and skin-interface interactions.
Topics: Adult; Body Temperature Regulation; Exercise; Female; Humans; Male; Rest; Skin; Skin Absorption; Skin Physiological Phenomena; Skin Temperature; Sweat; Sweat Glands; Sweating
PubMed: 29745799
DOI: 10.1152/japplphysiol.00872.2017 -
Nutrients Nov 2022Physiological and biological markers in different body fluids are used to measure the body's physiological or pathological status. In the field of sports and exercise... (Review)
Review
Physiological and biological markers in different body fluids are used to measure the body's physiological or pathological status. In the field of sports and exercise medicine, the use of these markers has recently become more popular for monitoring an athlete's training response and assessing the immediate or long-term effects of exercise. Although the effect of exercise on different physiological markers using various body fluids is well substantiated, no article has undertaken a review across multiple body fluids such as blood, saliva, urine and sweat. This narrative review aims to assess various physiological markers in blood, urine and saliva, at rest and after exercise and examines physiological marker levels obtained across similar studies, with a focus on the population and study methodology used. Literature searches were conducted using PRISMA guidelines for keywords such as exercise, physical activity, serum, sweat, urine, and biomarkers, resulting in an analysis of 15 studies for this review paper. When comparing the effects of exercise on physiological markers across different body fluids (blood, urine, and saliva), the changes detected were generally in the same direction. However, the extent of the change varied, potentially as a result of the type and duration of exercise, the sample population and subject numbers, fitness levels, and/or dietary intake. In addition, none of the studies used solely female participants; instead, including males only or both male and female subjects together. The results of some physiological markers are sex-dependent. Therefore, to better understand how the levels of these biomarkers change in relation to exercise and performance, the sex of the participants should also be taken into consideration.
Topics: Humans; Male; Female; Exercise; Sports; Body Fluids; Sweat; Biomarkers
PubMed: 36364948
DOI: 10.3390/nu14214685 -
Molecules (Basel, Switzerland) Jun 2023Sweat, a biofluid secreted naturally from the eccrine glands of the human body, is rich in several electrolytes, metabolites, biomolecules, and even xenobiotics that... (Review)
Review
Sweat, a biofluid secreted naturally from the eccrine glands of the human body, is rich in several electrolytes, metabolites, biomolecules, and even xenobiotics that enter the body through other means. Recent studies indicate a high correlation between the analytes' concentrations in the sweat and the blood, opening up sweat as a medium for disease diagnosis and other general health monitoring applications. However, low concentration of analytes in sweat is a significant limitation, requiring high-performing sensors for this application. Electrochemical sensors, due to their high sensitivity, low cost, and miniaturization, play a crucial role in realizing the potential of sweat as a key sensing medium. MXenes, recently developed anisotropic two-dimensional atomic-layered nanomaterials composed of early transition metal carbides or nitrides, are currently being explored as a material of choice for electrochemical sensors. Their large surface area, tunable electrical properties, excellent mechanical strength, good dispersibility, and biocompatibility make them attractive for bio-electrochemical sensing platforms. This review presents the recent progress made in MXene-based bio-electrochemical sensors such as wearable, implantable, and microfluidic sensors and their applications in disease diagnosis and developing point-of-care sensing platforms. Finally, the paper discusses the challenges and limitations of MXenes as a material of choice in bio-electrochemical sensors and future perspectives on this exciting material for sweat-sensing applications.
Topics: Humans; Wearable Electronic Devices; Sweat; Biosensing Techniques; Nanostructures
PubMed: 37375172
DOI: 10.3390/molecules28124617 -
Biosensors Dec 2022Sweat-rate measurement has received more and more attention, especially for specific groups, such as athletes, soldiers and manual workers, due to their excessive sweat...
Sweat-rate measurement has received more and more attention, especially for specific groups, such as athletes, soldiers and manual workers, due to their excessive sweat loss under prolonged intense heat stress, which increases the risk of dehydration and electrolyte imbalance. The highly effective manufacture of a sweat-sensing device is essential to its wide range of applications in perspiration-related physiological information detection. In this work, we propose a simple and cost-effective strategy for the manufacture of a microfluidic sweat-rate-sensing patch via laser cutting and transfer printing technology. A copper foil tape is used as the electrode for in situ admittance based sweat-rate-sensing. The detection circuits and measurement conditions are optimized to prevent the negative effect of an electrochemical reaction between a copper electrode and sweat for precise admittance measurement. In vitro and on-body experiments demonstrate that the copper electrode is applicable for admittance-based sweat sensing and is capable of achieving equivalent sensing accuracy as a gold electrode and that the proposed sensor structure can perform consecutive and accurate sweat-rate-sensing and facilitates a significant increase in manufacturing efficiency.
Topics: Humans; Sweat; Microfluidics; Copper; Electrodes; Wearable Electronic Devices; Biosensing Techniques
PubMed: 36671902
DOI: 10.3390/bios13010067