Search

PURPOSE: This study compared the voluntary fluid intake behavior of older men and women (54-70 yr) when provided cold, palatable beverages and ample opportunity to drink between repeated bouts of exercise in the heat. METHODS: Thirteen men and 14 women performed four bouts of 15-min cycling at 65% VO2peak followed by 15 min of rest at 30 degrees C and 50% relative humidity. In separate trials, subjects drank either a carbohydrate-electrolyte solution (CES) or water ad libitum during the rest periods and were unaware that their fluid intake was being measured. RESULTS: Fluid intake behavior was repeatable (intraclass correlation coefficient = 0.75), and subjects drank enough of either beverage to match sweating rates and maintain their body mass (BM). Fluid intake per kilogram of BM was greater with CES (18.7 +/- 2.2 vs 15.1 +/- 2.1 mL x kg(-1); P < 0.05), and plasma volume (PV) was better maintained during the CES trials (-1.3 +/- 1.1 vs -4.2 +/- 1.1% during the second half of the session). Women drank significantly more water than the men on a per kilogram basis (17.2 +/- 2.9 vs 12.8 +/- 1.7 mL x kg(-1) BM), and one woman (BM = 45.7 kg) became hyponatremic (S(NA) = 126 mmol x L(-1)) with symptoms during the water trial. CONCLUSION: Older adults drank enough to maintain fluid balance when palatable fluid was readily available; however, CES promoted greater voluntary fluid intake and restored PV losses faster than water. In addition, older women drank more water than men during interval exercise in the heat, which may put smaller women at an increased risk for developing hyponatremia. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effect of hydration status on the change in sweat sodium (Na + ), chloride (Cl - ), and potassium (K + ) concentrations during exercise-heat stress. Fifteen subjects (Six female, nine male; 29 ± 9 y; 71 ± 14 kg) completed 90 min of cycling (81% HR max ) in the heat (~33°C, 42% rh) with fluid replacement to maintain euhydration (EUH) or without fluid to dehydrate to 2.4 ± 0.4% body mass loss (DEH). Sweat was collected from the forehead (FH), right scapula (SCAP), and left (LVFA) and right (RVFA) ventral forearms using the absorbent pad technique at the beginning (0-30 min) and end of exercise (60-90 min). Sweat was analyzed for Na + , Cl - , and K + concentrations using ion chromatography. Data are reported as mean ± SD or median ± IQR. There were no differences (Paired t-tests or Wilcoxon signed-rank tests) between EUH and DEH in the change in sweat Na + (FH: 24.3 ± 21.5 vs. 30.8 ± 22.4 mmol/L; SCAP: 9.7 ± 6.2 vs. 9.6 ± 8.2 mmol/L; LVFA: 7.5 ± 6.0 vs. 5.6 ± 5.9 mmol/L; RVFA: 8.2 ± 8.6 vs. 7.8 ± 5.2 mmol/L), sweat Cl - , or sweat K + at any site (p = 0.07-0.99). The change in sweat electrolyte concentrations during 90 min of exercise in the heat was not significantly influenced by mild dehydration in recreational to moderately-trained male and female athletes., (© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Due to growing interest in the investigation of exercise induced sweat biomarkers to assess an individual's health and the increasing prevalence of tattoos in the world's population, investigators sought to determine whether local sweat concentrations and excretion rates of epidermal growth factor (EGF), interleukin (IL) -1α, IL-6, IL-8, cortisol, glucose, blood urea nitrogen (BUN), and lactate differ between tattooed and contralateral non-tattooed skin during exercise. Sixteen recreational exercisers [female (50%)] (age = 25-48 years) with ≥ 1 unilateral permanent tattoo [median tattoo age = 6 years, IQR = 5] on the arm/torso completed an outdoor group fitness session. There were no significant differences between tattooed and non-tattooed skin for sweat EGF, IL-1α, IL-8, cortisol, glucose, BUN, or lactate concentrations. There were no significant differences between tattooed and non-tattooed skin for sweat EGF, IL-1α, IL-8, cortisol, glucose, BUN, or lactate excretion rate. Findings suggest that permanent tattoos older than 1 year may not impact local sweat EGF, IL-1α, IL-8, cortisol, glucose, BUN, and lactate concentrations or excretion rates during exercise.Clinical trial identifier NCT04920266 was registered on June 9, 2021., (© 2024. The Author(s).)

In November 2021, the Oath of a Pharmacist was updated to include the following statement, "I will promote inclusion, embrace diversity, and advocate for justice to advance health equity." These words underscore the responsibility of Doctor of Pharmacy (PharmD) programs and the Accreditation Council for Pharmacy Education to reconsider how diversity, equity, inclusion, and antiracism are integrated within curricula and programmatic processes. To fully embrace the new Oath, the Accreditation Council for Pharmacy Education and PharmD programs should consider the incorporation of diversity, equity, inclusion, and antiracism concepts utilizing the recommendations of external expert bodies with overlapping and complementary frameworks. The intent is not to add more to the accreditation standards or curricula, but rather to intentionally integrate inclusive approaches into programmatic processes and delivery. This can be accomplished through the alignment of our accreditation standards, PharmD programs, and the Oath that is the foundation of the pharmacy profession., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Inc.)

Introduction: The use of sweat as a biofluid for non-invasive sampling and diagnostics is a popular area of research. However, concentrations of cortisol, glucose, and cytokines have not been described across anatomical regions or as time progresses throughout exercise., Purpose: To determine regional and time course differences in sweat cortisol, glucose, and select cytokines (EGF, IFN-γ, IL-1β, IL-1α, IL-1ra, TNF-α, IL-6, IL-8, and IL-10)., Methods: Sweat was collected with absorbent patches from eight subjects (24-44 y; 80.2 ± 10.2 kg) on the forehead (FH), right dorsal forearm (RDF), right scapula (RS), and right triceps (RT) at 0-25 min, 30-55 min, and 60-85 min during 90 min of cycling (~ 82% HR max ) in a heated chamber (32 °C, 50% rh). ANOVA was used to determine the effect of site and time on outcomes. Data are reported as LS means ± SE., Results: There was a significant effect of location on sweat analyte concentrations with FH having higher values than most other regions for cortisol (FH: 1.15 ± 0.08 ng/mL > RDF: 0.62 ± 0.09 ng/mL and RT: 0.65 ± 0.12 ng/mL, P = 0.02), IL-1ra (P < 0.0001), and IL-8 (P < 0.0001), but lower concentrations for glucose (P = 0.01), IL-1α (P < 0.0001), and IL-10 (P = 0.02). Sweat IL-1β concentration was higher on the RS than RT (P < 0.0001). Sweat cortisol concentration increased (25 min: 0.34 ± 0.10 ng/mL < 55 min: 0.89 ± 0.07 ng/mL < 85 min: 1.27 ± 0.07 ng/mL; P < 0.0001), while EGF (P < 0.0001), IL-1ra (P < 0.0001), and IL-6 (P = 0.02) concentrations decreased over time., Conclusion: Sweat analyte concentrations varied with time of sampling and anatomical region, which is essential information to consider when conducting future work in this area., Clinical Trial Identifier: NCT04240951 registered January 27, 2020., (© 2023. The Author(s).)

Rehydration is important for athlete performance and recovery. However, it can be challenging to follow appropriate fluid replacement practices due in part to difficulties in tracking fluid intake in real time. The purpose of this study was to determine the accuracy of a smart bottle in measuring fluid intake during exercise. Thirty male American football athletes drank from bottles equipped with a smart cap during outdoor pre-season practices (110 ± 30 min; 29.3 ± 3.0 °C; 75 ± 11% rh). The cap technology included optical sensors, microprocessors, batteries, and wireless connectivity that transmitted fluid volume data to a smartphone application in real-time. Reference measurements of fluid intake from the smart bottle were determined by gravimetry followed by conversion to volume using the density of the fluid consumed. There was no significant mean difference in fluid intake between the smart bottle and reference method (1220 ± 371 ml vs. 1236 ± 389 ml, p = 0.39 paired t test). Bland-Altman 95% limits of agreement between methods was - 212 to 180 ml. The smart bottle provided accurate measurements of fluid intake during exercise in real-world field conditions on a group level and within limits of agreement of - 212 to 180 ml (or approximately ± 15% of overall fluid intake) on an individual level., (© 2023. The Author(s).)

Purpose: Patients with hematologic malignancies are more optimistic than their oncologists and their expectations may be a barrier to timely hospice care. Patient expectations toward the end of life (EOL), however, have not been characterized. In this study, we analyzed interviews of bereaved caregivers to understand the expectations of patients diagnosed with acute myeloid leukemia and the factors that influenced those expectations, from diagnosis until death., Methods: Bereaved caregivers (n = 19) participated in an in-depth interview that included open-ended and semi-structured prompts, within 18 months following patient death. Interviews were analyzed using a modified grounded theory qualitative approach and constant comparative methods., Results: We identified three themes relevant to expectations: Taking Stock, Being Stuck, and Disruption. Caregivers described clear and optimistic early expectations that AML is treatable. It was understood that treatment was required to survive. Later, when treatment options were limited, patients and caregivers became stuck in a belief that the patient could continue to live indefinitely on supportive care or at least until new more effective treatments were available. Caregivers often realized that the patient was at the end of life only when faced with a disruption, an event or conversation that changed their expectations for indefinite patient survival., Conclusions: Caregivers described continued expectations for patient survival until presented with irrefutable evidence to the contrary. The study suggests patients and caregivers may make better EOL care decisions if their early optimism is deliberately moderated by ongoing conversations with clinicians that highlight the sentinel events that signal treatment failure and explain how expectations and goals are changing from living a longer life to dying a more comfortable death., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

This study determined the relative importance of several individual characteristics and dietary, environmental, and exercise factors in determining sweat [Na + ] during exercise. Data from 1944 sweat tests were compiled for a retrospective analysis. Stepwise multiple regression ( P < 0.05 threshold for inclusion) and T values were used to express the relative importance of each factor in a model. Three separate models were developed based on available independent variables: model 1 (1,944 sweat tests from 1,304 subjects); model 2 (subset with energy expenditure: 1,003 sweat tests from 607 subjects); model 3 (subset with energy expenditure, dietary sodium, and V̇o 2max : n = 48). Whole body sweat [Na + ] was predicted from forearm sweat patches in models 1 and 2 and directly measured using whole body washdown in model 3 . There were no significant effects of age group, race/ethnicity, relative humidity, exercise duration, pre-exercise urine specific gravity, exercise fluid balance, or dietary or exercise sodium intake on any model. Significant predictors in model 1 (adjusted r 2 = 0.17, P < 0.001) were season of the year (warm, T = -6.8), exercise mode (cycling, T = 6.8), sex (male, T = 4.9), whole body sweating rate ( T = 4.5), and body mass ( T = -3.0). Significant predictors in model 2 (adjusted r 2 = 0.19, P < 0.001) were season of the year (warm, T = -5.2), energy expenditure ( T = 4.7), exercise mode (cycling, T = 3.6), air temperature ( T = 3.0), and sex (male, T = 2.7). The only significant predictor in model 3 ( r 2 = 0.23, P < 0.001) was energy expenditure ( T = 3.8). In summary, the models accounted for 17%-23% of the variation in whole body sweat [Na + ] and energy expenditure and season of the year (proxy for heat acclimatization) were the most important factors. NEW & NOTEWORTHY This comprehensive analysis of a large, diverse data set contributes to our overall understanding of the factors that influence whole body sweat [Na + ]. The main finding was that energy expenditure was directly associated with whole body sweat [Na + ], potentially via the relation between energy expenditure and whole body sweating rate (WBSR). Warmer months (proxy for heat acclimatization) were associated with lower whole body sweat [Na + ]. Exercise mode, air temperature, and sex may also have small effects, but other variables (age group, race/ethnicity, fluid balance, sodium intake, relative V̇o 2max ) had no association with whole body sweat [Na + ]. Taken together, the models explained 17%-23% of the variation in whole body sweat [Na + ].

Background: Weeds are a significant barrier to rice production in California, exacerbated by lack of chemical control options and herbicide-resistance in persistent aquaphilic species. Oxyfluorfen-tolerant rice, created at the Rice Experiment Station (RES) in Biggs, California, was developed to provide an agronomic program for managing problematic grass and sedge rice-weeds including Oryza sativa f. spontanea Roshev. (weedy 'red' rice). Hand-pulling is the most common removal method for O. sativa spontanea because there are no herbicides registered for this pest in California. Oxyfluorfen was used in combination with oxyfluorfen-tolerant rice in 2019 and 2021 field studies to evaluate rice injury and weed control efficacy on prevalent rice-weed species. Additional studies were conducted in 2021 on University of California Davis campus to determine pre-emergent oxyfluorfen efficacy on four California O. sativa spontanea accessions., Results: Fields studies indicated minimal crop injury in the first 28 days after seeding (DAS), but no observable injury at 60 DAS in both years. Weed control with oxyfluorfen alone was 87% or greater for all weeds rated with the exception of Schoenoplectus mucronatus (L.) Palla (ricefield bulrush), and Leptochloa fascicularis (Lam.) A. Gray (bearded sprangletop) in both years. All O. sativa spontanea exposed to soil-applied oxyfluorfen successfully emerged through the soil surface, but became completely necrotic 28 days after flooding., Conclusion: Oxyfluorfen-tolerant rice system was demonstrated to be a viable management strategy for California rice growers who struggle with grass- and sedge-weed control as well as provide a novel herbicide option for California O. sativa spontanea management. © 2022 University of California, Davis. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2022 University of California, Davis. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Purpose: To compare local sweating rate (LSR) and local sweat sodium ([Na + ]), chloride ([Cl - ]), and potassium ([K + ]) concentrations of tattooed skin and contralateral non-tattooed skin during exercise., Methods: Thirty-three recreational exercisers (17 men, 16 women) with ≥ 1 unilateral permanent tattoo on the torso/arms were tested during cycling, running, or fitness sessions (26 ± 4 °C and 54 ± 13% relative humidity). Forty-eight tattoos with a range of ink colors, ages (3 weeks to 20 years), and densities (10-100%) were included. Before exercise, the skin was cleaned with alcohol and patches (3 M Tegaderm + Pad) were placed on the tattooed and contralateral non-tattooed skin. LSR was calculated from sweat mass (0.80 ± 0.31 g), patch surface area (11.9 cm 2 ), and duration (62 ± 14 min). Sweat [Na + ], [Cl - ], and [K + ] were measured via ion chromatography., Results: Based on the analysis of variance results, there were no differences between tattooed and non-tattooed skin for LSR (1.16 ± 0.52 vs. 1.12 ± 0.53 mg/cm 2 /min; p = 0.51), sweat [Na + ] (60.2 ± 23.5 vs. 58.5 ± 22.7 mmol/L; p = 0.27), sweat [Cl - ] (52.1 ± 22.4 vs. 50.6 ± 22.0 mmol/L; p = 0.31), or sweat [K + ] (5.8 ± 1.6 vs. 5.9 ± 1.4 mmol/L; p = 0.31). Multiple regression analyses suggested that younger tattoos were associated with higher sweat [Na + ] (p = 0.045) and colorful tattoos were associated with higher sweat [Cl - ] (p = 0.04) compared with contralateral non-tattooed skin. Otherwise, there were no effects of LSR or tattoo characteristics on regression models for LSR or sweat electrolyte concentrations., Conclusion: There were no effects of tattoos on LSR and sweat [K + ] during exercise-induced sweating, but tattoo age and color had small effects on sweat [Na + ] and sweat [Cl - ], respectively., Clinical Trial Identifiers: NCT04240951 was registered on January 27, 2020 and NCT04920266 was registered on June 9, 2021., (© 2022. The Author(s).)

Basketball players face multiple challenges to in-season recovery. The purpose of this article is to review the literature on recovery modalities and nutritional strategies for basketball players and practical applications that can be incorporated throughout the season at various levels of competition. Sleep, protein, carbohydrate, and fluids should be the foundational components emphasized throughout the season for home and away games to promote recovery. Travel, whether by air or bus, poses nutritional and sleep challenges, therefore teams should be strategic about packing snacks and fluid options while on the road. Practitioners should also plan for meals at hotels and during air travel for their players. Basketball players should aim for a minimum of 8 h of sleep per night and be encouraged to get extra sleep during congested schedules since back-to back games, high workloads, and travel may negatively influence night-time sleep. Regular sleep monitoring, education, and feedback may aid in optimizing sleep in basketball players. In addition, incorporating consistent training times may be beneficial to reduce bed and wake time variability. Hydrotherapy, compression garments, and massage may also provide an effective recovery modality to incorporate post-competition. Future research, however, is warranted to understand the influence these modalities have on enhancing recovery in basketball players. Overall, a strategic well-rounded approach, encompassing both nutrition and recovery modality strategies, should be carefully considered and implemented with teams to support basketball players' recovery for training and competition throughout the season., (© 2021. The Author(s).)

The purpose of this study was to compare a wearable microfluidic device and standard absorbent patch in measuring local sweating rate (LSR) and sweat chloride concentration ([Cl-]) in elite basketball players. Participants were 53 male basketball players (25 ± 3 years, 92.2 ± 10.4 kg) in the National Basketball Association's development league. Players were tested during a moderate-intensity, coach-led practice (98 ± 30 min, 21.0 ± 1.2 °C). From the right ventral forearm, sweat was collected using an absorbent patch (3M Tegaderm™ + Pad). Subsequently, LSR and local sweat [Cl-] were determined via gravimetry and ion chromatography. From the left ventral forearm, LSR and local sweat [Cl-] were measured using a wearable microfluidic device and associated smartphone application-based algorithms. Whole-body sweating rate (WBSR) was determined from pre- to postexercise change in body mass corrected for fluid/food intake (ad libitum), urine loss, and estimated respiratory water and metabolic mass loss. The WBSR values predicted by the algorithms in the smartphone application were also recorded. There were no differences between the absorbent patch and microfluidic patch for LSR (1.25 ± 0.91 mg·cm-2·min-1 vs. 1.14 ±0.78 mg·cm-2·min-1, p = .34) or local sweat [Cl-] (30.6 ± 17.3 mmol/L vs. 29.6 ± 19.4 mmol/L, p = .55). There was no difference between measured and predicted WBSR (0.97 ± 0.41 L/hr vs. 0.89 ± 0.35 L/hr, p = .22; 95% limits of agreement = 0.61 L/hr). The wearable microfluidic device provides similar LSR, local sweat [Cl-], and WBSR results compared with standard field-based methods in elite male basketball players during moderate-intensity practices.

Aims: The inability to prescribe blood transfusions is a potential barrier to timely hospice enrollment for patients with blood cancers. The benefits and harms of transfusions near the end of life (EOL), however, are poorly characterized and patients' preferences are unknown. We sought to characterize the recollections of bereaved caregivers about the relationships between transfusions and hospice enrollment decisions., Methods: We recruited 18 bereaved caregivers of 15 decedents who died within 6-18 months of the interview. Interviews focused on caregivers' recollections of transfusion and hospice enrollment decisions. Transcripts were analyzed for themes., Results: We identified 2 themes. First, caregivers described that transfusions were necessary and the decisions to receive transfusions or not were deferred to the clinicians. Second, only 1 caregiver recalled transfusions as relevant to hospice decisions. In that instance there was a delay. Caregivers identified difficulties recognizing death was imminent, hope for miracles, and the necessity of accepting life was ending as more relevant barriers., Conclusions: The results indicate clinicians' beliefs in transfusion at EOL may be a more relevant barrier to hospice enrollment than patients' preferences. Strategies to evaluate accurately and discuss the actual benefits and harms of transfusions at the EOL are necessary to advise patients and integrate their preferences into decisions.

Introduction: a district health information system 2 tool with a customized routine immunization (RI) module and indicator dashboard was introduced in Kano State, Nigeria, in November 2014 to improve data management and analysis of RI services. We assessed the use of the module for program monitoring and decision-making, as well as the enabling factors and barriers to data collection and use., Methods: a mixed-methods approach was used to assess user experience with the RI data module and dashboard, including 1) a semi-structured survey questionnaire administered at 60 health facilities administering vaccinations and 2) focus group discussions and 16 in-depth interviews conducted with immunization program staff members at the local government area (LGA) and state levels., Results: in health facilities, a RI monitoring chart was used to review progress toward meeting vaccination coverage targets. At the LGA, staff members used RI dashboard data to prioritize health facilities for additional support. At the State level, immunization program staff members use RI data to make policy decisions. They viewed the provision of real-time data through the RI dashboard as a "game changer". Use of immunization data is facilitated through review meetings and supportive supervision visits. Barriers to data use among LGA staff members included inadequate understanding of the data collection tools and computer illiteracy., Conclusion: the routine immunization data dashboard facilitated access to and use of data for decision-making at the LGA, State and national levels, however, use at the health facility level remains limited. Ongoing data review meetings and training on computer skills and data collection tools are recommended., (©Dieula Delissaint Tchoualeu et al.)

Family-centered practices that involve direct participation of caregivers as part of intervention is critical to effective early intervention. However, regularly scheduled, in person service delivery is not always possible in remote communities, prompting a need for adaptations to the delivery of services, such as the use of live video conferencing to coach caregivers in strategies to promote their children's development. In this study, caregivers and their children ages 2-9 with autism who were living in rural and remote Canadian communities were included. A concurrent multiple baseline design across participants was applied to examine the effects of live video conference caregiver coaching on children's time jointly engaged with caregivers and caregivers' intervention strategy implementation. Results indicated that all children demonstrated greater time jointly engaged and caregivers demonstrated greater use of strategies in comparison to baseline. The results of this study offer preliminary evidence of the effectiveness of real time video conference coaching for caregivers engaging their children with ASD in play., (©AAIDD.)

Intestinal barrier integrity and function are compromised during exertional heat stress (EHS) potentially leading to consequences that range from minor gastrointestinal (GI) disturbances to fatal outcomes in exertional heat stroke or septic shock. This mini-review provides a concise discussion of nutritional interventions that may protect against intestinal permeability during EHS and suggests physiological mechanisms responsible for this protection. Although diverse nutritional interventions have been suggested to be protective against EHS-induced GI permeability, the ingestion of certain amino acids, carbohydrates, and fluid per se is potentially effective strategy, whereas evidence for various polyphenols and pre/probiotics is developing. Plausible physiological mechanisms of protection include increased blood flow, epithelial cell proliferation, upregulation of intracellular heat shock proteins, modulation of inflammatory signaling, alteration of the GI microbiota, and increased expression of tight junction (TJ) proteins. Further clinical research is needed to propose specific nutritional candidates and recommendations for their application to prevent intestinal barrier disruption and elucidate mechanisms during EHS.

This study tested the accuracy of a novel, limited-availability web application (H 2 Q™) for predicting sweat rates in a variety of sports using estimates of energy expenditure and air temperature only. The application of predictions for group water planning was investigated for soccer match play. Fourteen open literature studies were identified where group sweat rates were reported (n = 20 group means comprising 230 individual observations from 179 athletes) with fidelity. Sports represented included: walking, cycling, swimming, and soccer match play. The accuracy of H 2 Q™ sweat rates was tested by comparing to measured group sweat rates using the concordance correlation coefficient (CCC) with 95% confidence interval [CI]. The relative absolute error (RAE) with 95% [CI] was also assessed, whereby the mean absolute error was expressed relative to an acceptance limit of 0.250 L/h. The CCC was 0.98 [0.95, 0.99] and the RAE was 0.449 [0.279, 0.620], indicating that the prediction error was on average 0.112 L/h. The RAE was < 1.0 for 19/20 observations (95%). Drink volumes modeled as a proxy for sweat losses during soccer match play prevented dehydration (< 1% loss of body mass). The H 2 Q™ web application demonstrated high group sweat prediction accuracy for the variety of sports activities tested. Water planning for soccer match play suggests the feasibility of easily and accurately predicting sweat rates to plan group water needs and promote optimal hydration in training and/or competition., Competing Interests: Author SNC is the owner of Sports Science Synergy, LLC and creator of the H2Q™ web application (patent pending). Author LBB is employed by PepsiCo, Inc. The soccer pilot study was funded by the Gatorade Sports Science Institute, a division of PepsiCo, Inc. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of PepsiCo, Inc., (Copyright © Biology of Sport 2021.)

Advanced capabilities in noninvasive, in situ monitoring of sweating rate and sweat electrolyte losses could enable real-time personalized fluid-electrolyte intake recommendations. Established sweat analysis techniques using absorbent patches require post-collection harvesting and benchtop analysis of sweat and are thus impractical for ambulatory use. Here, we introduce a skin-interfaced wearable microfluidic device and smartphone image processing platform that enable analysis of regional sweating rate and sweat chloride concentration ([Cl - ]). Systematic studies ( n = 312 athletes) establish significant correlations for regional sweating rate and sweat [Cl - ] in a controlled environment and during competitive sports under varying environmental conditions. The regional sweating rate and sweat [Cl - ] results serve as inputs to algorithms implemented on a smartphone software application that predicts whole-body sweating rate and sweat [Cl - ]. This low-cost wearable sensing approach could improve the accessibility of physiological insights available to sports scientists, practitioners, and athletes to inform hydration strategies in real-world ambulatory settings., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY).)

Global audiences are captivated by climbers pushing themselves to the limits in the hypoxic environment of Mount Everest. However, air pressure sets oxygen abundance, meaning it varies with the weather and climate warming. This presents safety issues for mountaineers but also an opportunity for public engagement around climate change. Here we blend new observations from Everest with ERA5 reanalysis (1979-2019) and climate model results to address both perspectives. We find that plausible warming could generate subtle but physiologically relevant changes in summit oxygen availability, including an almost 5% increase in annual minimum VO 2 max for 2°C warming since pre-industrial. In the current climate we find evidence of swings in pressure sufficient to change Everest's apparent elevation by almost 750 m. Winter pressures can also plunge lower than previously reported, highlighting the importance of air pressure forecasts for the safety of those trying to push the physiological frontier on Mt. Everest., Competing Interests: The authors declare no competing interests., (© 2020 The Authors.)

Background: Although growing, the prevalence of the use of health information technology (HIT) by patients to communicate with their providers is not well understood on the population level, nor whether patients are communicating with their providers about their use of HIT., Objective: To understand whether patients are communicating with their providers about HIT use and the patient characteristics associated with the communication., Design: Cross-sectional, self-administered survey of a sample of patients across the state of Indiana., Participants: Nine hundred seventy adult participants from across Indiana, 54% female and 79.5% white., Main Measures: The survey included sections assessing health information-seeking behavior, use of health information technology, and discussions with doctors about the use of HIT., Key Results: The survey had a 12% response rate. Sixty-three percent of respondent reported going to the Internet as the first source when seeking health information, while only 19% of respondent reported their doctor was their first source. When communicating with doctors electronically, 31% reported using an electronic health record messaging system, 24% used email, and 18% used text messaging. Only 39% of respondents reported having had any conversation about HIT use with their providers., Conclusions: There remain many unmet opportunities for patients and providers to communicate about HIT use. More guidance for patients and care teams may both help facilitate these conversations and promote optimal use, such as recommendations to ask simple clarification questions and minimize inefficient, synchronous communication when unnecessary.

We have previously published equations to estimate whole-body (WB) sweat sodium concentration ([Na + ]) from regional (REG) measures; however, a cross-validation is needed to corroborate the applicability of these prediction equations between studies. The purpose of this study was to determine the validity of published equations in predicting WB sweat [Na + ] from REG measures when applied to a new data set. Forty-nine participants (34 men, 15 women; 75 ± 12 kg) cycled for 90 min while WB sweat [Na + ] was measured using the washdown technique. REG sweat [Na + ] was measured from seven regions using absorbent patches (3M Tegaderm + Pad). Published equations were applied to REG sweat [Na + ] to determine predicted WB sweat [Na + ]. Bland-Altman analysis of mean bias (raw and predicted minus measured) and 95% limits of agreement (LOA) were used to compare raw (uncorrected) REG sweat [Na + ] and predicted WB sweat [Na + ] to measured WB sweat [Na + ]. Mean bias (±95% LOA) between raw REG sweat [Na + ] and measured WB sweat [Na + ] was 10(±20), 0(±19), 9(±20), 22(±25), 23(±24), 0(±15), -4(±18) mmol/L for the dorsal forearm, ventral forearm, upper arm, chest, upper back, thigh, and calf, respectively. The mean bias (±95% LOA) between predicted WB sweat [Na + ] and measured WB sweat [Na + ] was 3(±14), 4(±12), 0(±14), 2(±17), -2(±16), 5(±13), 4(±15) mmol/L for the dorsal forearm, ventral forearm, upper arm, chest, upper back, thigh, and calf, respectively. Prediction equations improve the accuracy of estimating WB sweat [Na + ] from REG and are therefore recommended for use when determining individualized sweat electrolyte losses., (© 2020 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Purposes: This study investigated the impact of permanently tattooed skin on local sweat rate, sweat sodium concentration and skin temperature and determined whether tattoos alter the relationship between local and whole-body sweat sodium concentration., Methods: Thirteen tattooed men (27 ± 6 years) completed a 1 h (66 ± 4% of [Formula: see text]) cycling trial at 32 °C, 35% relative humidity. Sweat rate and sweat sodium concentration were measured using the whole-body washdown and local absorbent patch techniques. Patches and skin-temperature probes were applied over the right/left thighs and tattooed/non-tattooed (contralateral) regions., Results: Local sweat rates did not differ (p > 0.05) between the right (1.11 ± 0.38) and left (1.21 ± 0.37) thighs and the permanently tattooed (1.93 ± 0.82) and non-tattooed (1.72 ± 0.81 mg cm -2  min -1 ) regions. There were no differences in local sweat sodium concentration between the right (58.2 ± 19.4) and left (55.4 ± 20.3) thighs and the permanently tattooed (73.0 ± 22.9) and non-tattooed (70.2 ± 18.9 mmol L -1 ) regions. Difference in local skin temperature between the right and left thighs (- 0.043) was similar to that between the permanently tattooed and non-tattooed (- 0.023 °C) regions. Prediction of whole-body sweat sodium concentration for the permanently tattooed (41.0 ± 6.7) and the non-tattooed (40.2 ± 5.3 mmol L -1 ) regions did not differ., Conclusion: Permanent tattoos do not alter local sweat rate, sweat sodium concentration or local skin temperature during moderate-intensity cycling exercise in a warm environment. Results from a patch placed over a tattooed surface correctly predicts whole-body sweat sodium concentration from an equation developed from a non-tattooed region.

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.

The purpose of this study was to expand our previously published sweat normative data/analysis (n = 506) to establish sport-specific normative data for whole-body sweating rate (WBSR), sweat [Na + ], and rate of sweat Na + loss (RSSL). Data from 1303 athletes were compiled from observational testing (2000-2017) using a standardized absorbent sweat patch technique to determine local sweat [Na + ] and normalized to whole-body sweat [Na + ]. WBSR was determined from change in exercise body mass, corrected for food/fluid intake and urine/stool loss. RSSL was the product of sweat [Na + ] and WBSR. There were significant differences between sports for WBSR, with highest losses in American football (1.51 ± 0.70 L/h), then endurance (1.28 ± 0.57 L/h), followed by basketball (0.95 ± 0.42 L/h), soccer (0.94 ± 0.38 L/h) and baseball (0.83 ± 0.34 L/h). For RSSL, American football (55.9 ± 36.8 mmol/h) and endurance (51.7 ± 27.8 mmol/h) were greater than soccer (34.6 ± 19.2 mmol/h), basketball (34.5 ± 21.2 mmol/h), and baseball (27.2 ± 14.7 mmol/h). After ANCOVA, significant between-sport differences in adjusted means for WBSR and RSSL remained. In summary, due to the significant sport-specific variation in WBSR and RSSL, American football and endurance have the greatest need for deliberate hydration strategies. Abbreviations: WBSR: whole body sweating rate; SR: sweating rate; Na + : sodium; RSSL: rate of sweat sodium loss.

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., (© 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Personalized hydration strategies play a key role in optimizing the performance and safety of athletes during sporting activities. Clinicians should be aware of the many physiological, behavioral, logistical and psychological issues that determine both the athlete's fluid needs during sport and his/her opportunity to address them; these are often specific to the environment, the event and the individual athlete. In this paper we address the major considerations for assessing hydration status in athletes and practical solutions to overcome obstacles of a given sport. Based on these solutions, practitioners can better advise athletes to develop practices that optimize hydration for their sports.

Background: This statewide survey examined differences in cancer-related knowledge, beliefs, and behaviors between racial and socioeconomic groups in select counties in Indiana., Methods: A stratified random sample of 7,979 people aged 18-75 who lived in one of 34 Indiana counties with higher cancer mortality rates than the state average, and were seen at least once in the past year in a statewide health system were mailed surveys., Results: Completed surveys were returned by 970 participants, yielding a 12% response rate. Black respondents were less likely to perceive they were at risk for cancer and less worried about getting cancer. Individuals most likely to perceive that they were unlikely to get cancer were more often black, with low incomes (less than $20,000) or high incomes ($50,000 or more), or less than a high school degree. Black women were greater than six times more likely to be adherent to cervical cancer screening. Higher income was associated with receiving a sigmoidoscopy in the last 5 years and a lung scan in the past year. Those with the highest incomes were more likely to engage in physical activity. Both income and education were inversely related to smoking., Conclusions: Socioeconomic and racial disparities were observed in health behaviors and receipt of cancer screening. Black individuals had less worry about cancer., Impact: Understanding populations for whom cancer disparities exist and geographic areas where the cancer burden is disproportionately high is essential to decision-making about research priorities and the use of public health resources., (©2018 American Association for Cancer Research.)

Background: This statewide survey sought to understand the adoption level of new health information and medical technologies, and whether these patterns differed between urban and rural populations., Methods: A random sample of 7,979 people aged 18-75 years, stratified by rural status and race, who lived in 1 of 34 Indiana counties with high cancer mortality rates and were seen at least once in the past year in a statewide health system were surveyed., Results: Completed surveys were returned by 970 participants. Rural patients were less likely than urban to use electronic health record messaging systems (28.3% vs 34.5%, P = .045) or any communication technology (43.0% vs 50.8%, P = .017). Rural patients were less likely to look for personal health information for someone else's medical record (11.0% vs 16.3%, P = .022), look-up test results (29.5% vs 38.3%, P = .005), or use any form of electronic medical record (EMR) access (57.5% vs 67.1%, P = .003). Rural differences in any use of communication technology or EMRs were no longer significant in adjusted models, while education and income were significantly associated. There was a trend in the higher use of low-dose computed tomography (CT) scan among rural patients (19.1% vs 14.4%, P = .057). No significant difference was present between rural and urban patients in the use of the human papilloma virus test (27.1% vs 26.6%, P = .880)., Conclusions: Differences in health information technology use between rural and urban populations may be moderated by social determinants. Lower adoption of new health information technologies (HITs) than medical technologies among rural, compared to urban, individuals may be due to lower levels of evidence supporting HITs., (© 2019 National Rural Health Association.)

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 VO 2max 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% VO 2max ), but other sites (especially ventral wrist, lower back, thigh, and calf) require separate prediction equations accounting for workload.

Although adequate hydration is essential for health, little attention has been paid to the effects of hydration among the generally healthy population. This narrative review presents the state of the science on the role of hydration in health in the general population, specifically in skin health, neurological function (i.e., cognition, mood, and headache), gastrointestinal and renal functions, and body weight and composition. There is a growing body of evidence that supports the importance of adequate hydration in maintaining proper health, especially with regard to cognition, kidney stone risk, and weight management. However, the evidence is largely associative and lacks consistency, and the number of randomized trials is limited. Additionally, there are major gaps in knowledge related to health outcomes due to small variations in hydration status, the influence of sex and sex hormones, and age, especially in older adults and children.

Background: Cerebral palsy occurs in up to 2.1 of every 1000 live births and encompasses a range of motor problems and movement disorders. One commonly occurring movement disorder amongst those with cerebral palsy is dystonia: sustained or intermittent involuntary muscle spasms and contractions that cause twisting, repetitive movements and abnormal postures. The involuntary contractions are often very painful and distressing and cause significant limitations to activity and participation.Oral medications are often the first line of medical treatment for dystonia. Trihexyphenidyl is one such medication that clinicians often use to treat dystonia in people with cerebral palsy., Objectives: To assess the effects of trihexyphenidyl in people with dystonic cerebral palsy, according to the World Health Organization's (WHO) International Classification of Functioning, Disability and Health (ICF) domains of impairment, activity and participation. We also assessed the type and incidence of adverse effects in people taking the drug., Search Methods: We searched CENTRAL, MEDLINE, Embase, eight other databases and two trials registers in May 2017, and we checked reference lists and citations to identify additional studies., Selection Criteria: We included randomised controlled trials comparing oral trihexyphenidyl versus placebo for dystonia in cerebral palsy. We included studies in children and adults of any age with dystonic cerebral palsy, either in isolation or with the associated movement disorders of spasticity, ataxia, chorea, athetosis and/or hypotonia. We included studies regardless of whether or not the study authors specified the method used to diagnose dystonia in their study population. Primary outcomes were change in dystonia and adverse effects. Secondary outcomes were: activity, including mobility and upper limb function; participation in activities of daily living; pain; and quality of life., Data Collection and Analysis: We used standard methodological procedures expected by Cochrane., Main Results: We identified one study, which was set in Australia, that met the inclusion criteria. This was a randomised, double-blind, placebo-controlled, cross-over trial in 16 children (10 boys and 6 girls) with predominant dystonic cerebral palsy and a mean age of 9 years (standard deviation 4.3 years, range 2 to 17 years). We considered the trial to be at low risk of selection, performance, detection, attrition, reporting and other sources of bias. We rated the GRADE quality of the evidence as low.We found no difference in mean follow-up scores for change in dystonia as measured by the Barry Albright Dystonia Scale (BADS), which assesses eight body regions for dystonia on a 5-point scale (0 = none to 4 = severe), resulting in a total score of 0 to 32. The BADS score was 2.67 points higher (95% confidence interval (CI) -2.55 to 7.90; low-quality evidence), that is, worse dystonia, in the treated group. Trihexyphenidyl may be associated with an increased risk of adverse effects (risk ratio 2.54, 95% CI 1.38 to 4.67; low-quality evidence).There was no difference in mean follow-up scores for upper limb function as measured by the Quality of Upper Extremity Skills Test, which has four domains that collectively assess 36 items (each scored 1 or 2) and produces a total score of 0 to 100. The score in the treated group was 4.62 points lower (95% CI -10.98 to 20.22; low-quality evidence), corresponding to worse function, than in the control group. We found low-quality evidence for improved participation (as represented by higher scores) in the treated group in activities of daily living, as measured by three tools: 18.86 points higher (95% CI 5.68 to 32.03) for the Goal Attainment Scale (up to five functional goals scored on 5-point scale (-2 = much less than expected to +2 = much more than expected)), 2.91 points higher (95% CI 1.01 to 4.82) for the satisfaction subscale of the Canadian Occupational Performance Measure (COPM; satisfaction with performance in up to five problem areas scored on a 10-point scale (1 = not satisfied at all to 10 = extremely satisfied)), and 2.24 points higher (95% CI 0.64 to 3.84) for performance subscale of the COPM (performance in up to five problem areas scored on a 10-point scale (1 = not able to do to; 10 = able to do extremely well)).The study did not report on pain or quality of life., Authors' Conclusions: At present, there is insufficient evidence regarding the effectiveness of trihexyphenidyl for people with cerebral palsy for the outcomes of: change in dystonia, adverse effects, increased upper limb function and improved participation in activities of daily living. The study did not measure pain or quality of life. There is a need for larger randomised, controlled, multicentre trials that also examine the effect on pain and quality of life in order to determine the effectiveness of trihexyphenidyl for people with cerebral palsy.

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 ( r 2 ) were 0.44-0.69 for RSR predicting WBSR [best predictors: dorsal forearm ( r 2  = 0.62) and triceps ( r 2  = 0.69)] and 0.55-0.77 for REG predicting WB sweat [Na + ] [best predictors: ventral forearm ( r 2  = 0.73) and thigh ( r 2  = 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.

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.

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.

The B-722 Laqua Twin is a low cost, portable, and battery operated sodium analyzer, which can be used for the assessment of sweat sodium concentration. The Laqua Twin is reliable and provides a degree of accuracy similar to more expensive analyzers; however, its interunit measurement error remains unknown. The purpose of this study was to compare the sodium concentration values of 70 sweat samples measured using three different Laqua Twin units. Mean absolute errors, random errors and constant errors among the different Laqua Twins ranged respectively between 1.7 mmol/L to 3.5 mmol/L, 2.5 mmol/L to 3.7 mmol/L and -0.6 mmol/L to 3.9 mmol/L. Proportional errors among Laqua Twins were all < 2%. Based on a within-subject biological variability in sweat sodium concentration of ± 12%, the maximal allowable imprecision among instruments was considered to be £ 6%. In that respect, the within (2.9%), between (4.5%), and total (5.4%) measurement error coefficient of variations were all < 6%. For a given sweat sodium concentration value, the largest observed difference in mean and lower and upper bound error of measurements among instruments were, respectively, 4.7 mmol/L, 2.3 mmol/L, and 7.0 mmol/L. In conclusion, our findings show that the interunit measurement error of the B-722 Laqua Twin is low and methodologically acceptable.

Team sport athletes face a variety of nutritional challenges related to recovery during the competitive season. The purpose of this article is to review nutrition strategies related to muscle regeneration, glycogen restoration, fatigue, physical and immune health, and preparation for subsequent training bouts and competitions. Given the limited opportunities to recover between training bouts and games throughout the competitive season, athletes must be deliberate in their recovery strategy. Foundational components of recovery related to protein, carbohydrates, and fluid have been extensively reviewed and accepted. Micronutrients and supplements that may be efficacious for promoting recovery include vitamin D, omega-3 polyunsaturated fatty acids, creatine, collagen/vitamin C, and antioxidants. Curcumin and bromelain may also provide a recovery benefit during the competitive season but future research is warranted prior to incorporating supplemental dosages into the athlete's diet. Air travel poses nutritional challenges related to nutrient timing and quality. Incorporating strategies to consume efficacious micronutrients and ingredients is necessary to support athlete recovery in season.

Sweat losses in team sports can be significant due to repeated bursts of high-intensity activity, as well as the large body size of athletes, equipment and uniform requirements, and environmental heat stress often present during training and competition. In this paper we aimed to: (1) describe sweat losses and fluid balance changes reported in team sport athletes, (2) review the literature assessing the impact of hypohydration on cognitive, technical, and physical performance in sports-specific studies, (3) briefly review the potential mechanisms by which hypohydration may impact team sport performance, and (4) discuss considerations for future directions. Significant hypohydration (mean body mass loss (BML) >2%) has been reported most consistently in soccer. Although American Football, rugby, basketball, tennis, and ice hockey have reported high sweating rates, fluid balance disturbances have generally been mild (mean BML <2%), suggesting that drinking opportunities were sufficient for most athletes to offset significant fluid losses. The effect of hydration status on team sport performance has been studied mostly in soccer, basketball, cricket, and baseball, with mixed results. Hypohydration typically impaired performance at higher levels of BML (3-4%) and when the method of dehydration involved heat stress. Increased subjective ratings of fatigue and perceived exertion consistently accompanied hypohydration and could explain, in part, the performance impairments reported in some studies. More research is needed to develop valid, reliable, and sensitive sport-specific protocols and should be used in future studies to determine the effects of hypohydration and modifying factors (e.g., age, sex, athlete caliber) on team sport performance.

The aims of this study were to determine: (1) trapped sweat (TS) in basketball uniforms and the effect on sweat loss (SL) estimates during a laboratory-based basketball simulation protocol; (2) the impact of exercise intensity, body mass, age, and SL on TS; and (3) TS during on-court training to assess the ecological validity of the laboratory-based results. Twenty-four recreational/competitive male basketball players (23 ± 10 years, 77.0 ± 16.7 kg) completed three randomized laboratory-based trials (Low, Moderate, and High intensity) consisting of 150-min intermittent exercise. Eighteen elite male players (23 ± 4 years, 92.0 ± 20.6 kg) were observed during coach-led, on-court training. Nude and clothed body mass were measured pre and postexercise to determine TS. Data are mean ± SD. There was a significant effect of intensity on SL and TS ( P  < 0.001, Low

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.

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.

Numerous studies have reported on the thermoregulation and hydration challenges athletes face in team and individual sports during exercise in the heat. Comparatively less research, however, has been conducted on the American Football player. Therefore, the purpose of this article is to review data collected in laboratory and field studies and discuss the thermoregulation, fluid balance, and sweat losses of American Football players. American Football presents a unique challenge to thermoregulation compared with other sports because of the encapsulating nature of the required protective equipment, large body size of players, and preseason practice occurring during the hottest time of year. Epidemiological studies report disproportionately higher rates of exertional heat illness and heat stroke in American Football compared with other sports. Specifically, larger players (e.g., linemen) are at increased risk for heat ailments compared with smaller players (e.g., backs) because of greater body mass index, increased body fat, lower surface area to body mass ratio, lower aerobic capacity, and the stationary nature of the position, which can reduce heat dissipation. A consistent finding across studies is that larger players exhibit higher sweating rates than smaller players. Mean sweating rates from 1.0 to 2.9 L/h have been reported for college and professional American Football players, with several studies reporting 3.0 L/h or more in some larger players. Sweat sodium concentration of American Football players does not seem to differ from that of athletes in other sports; however, given the high volume of sweat loss, the potential for sodium loss is higher in American Football than in other sports. Despite high sweating rates with American Football players, the observed disturbances in fluid balance have generally been mild (mean body mass loss ≤2 %). The majority of field-based studies have been conducted in the northeastern part of the United States, with limited studies in different geographical regions (i.e., southeast) of the United States. Further, there have been a limited number of studies examining body core temperature of American Football players during preseason practice, especially at the high school level. Future field-based research in American Football with various levels of competition in hotter geographical regions of the United States is warranted.

The purpose of this study was to establish normative data for regional sweat sodium concentration ([Na+]) and whole-body sweating rate in athletes. Data from 506 athletes (367 adults, 139 youth; 404 male, 102 female) were compiled from observational athlete testing for a retrospective analysis. The participants were skill/team-sport (including American football, baseball, basketball, soccer and tennis) and endurance (including cycling, running and triathlon) athletes exercising in cool to hot environmental conditions (15-50 °C) during training or competition in the laboratory or field. A standardised regional absorbent patch technique was used to determine sweat [Na+] on the dorsal mid-forearm. Whole-body sweat [Na+] was predicted using a published regression equation (y = 0.57x+11.05). Whole-body sweating rate was calculated from pre- to post-exercise change in body mass, corrected for fluid/food intake (ad libitum) and urine output. Data are expressed as mean ± SD (range). Forearm sweat [Na+] and predicted whole-body sweat [Na+] were 43.6 ± 18.2 (12.6-104.8) mmol · L(-1) and 35.9 ± 10.4 (18.2-70.8) mmol · L(-1), respectively. Absolute and relative whole-body sweating rates were 1.21 ± 0.68 (0.26-5.73) L · h(-1) and 15.3 ± 6.8 (3.3-69.7) ml · kg(-1) · h(-1), respectively. This retrospective analysis provides normative data for athletes' forearm and predicted whole-body sweat [Na+] as well as absolute and relative whole-body sweating rate across a range of sports and environmental conditions.

Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1-2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30-60 g/h in the form of a 6%-7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a game seems to have the greatest impact on intermittent sports performance towards the end of the game.

Purpose: To determine if tear fluid osmolarity (Tosm) can track changes in hydration status during exercise and post-exercise rehydration., Methods: Nineteen male athletes (18-37 years, 74.6 ± 7.9 kg) completed two randomized, counterbalanced trials; cycling (~95 min) with water intake to replace fluid losses or water restriction to progressively dehydrate to 3 % body mass loss (BML). After exercise, subjects drank water to maintain body mass (water intake trials) or progressively rehydrate to pre-exercise body mass (water restriction trials) over a 90-min recovery period. Plasma osmolality (Posm) and Tosm measurements (mean of right and left eyes) were taken pre-exercise, during rest periods between exercise bouts corresponding to 1, 2, and 3 % BML, and rehydration at 2, 1, and 0 % BML., Results: During exercise mean (± SD) Tosm was significantly higher in water restriction vs. water intake trials at 1 % BML (299 ± 9 vs. 293 ± 9 mmol/L), 2 % BML (301 ± 9 vs. 294 ± 9 mmol/L), and 3 % BML (302 ± 9 vs. 292 ± 8 mmol/L). Mean Tosm progressively decreased during post-exercise rehydration and was not different between trials at 1 % BML (291 ± 8 vs. 290 ± 7 mmol/L) and 0 % BML (288 ± 7 vs. 289 ± 8 mmol/L). Mean Tosm tracked changes in hydration status similar to that of mean Posm; however, the individual responses in Tosm to water restriction and water intake was considerably more variable than that of Posm., Conclusion: Tosm is a valid indicator of changes in hydration status when looking at the group mean; however, large differences among subjects in the Tosm response to hydration changes limit its validity for individual recommendations.

Performance in many sports is at least partially dependent on motor control, coordination, decision-making, and other cognitive tasks. This review summarizes available evidence about the ingestion of selected nutrients or isolated compounds (dietary constituents) and potential acute effects on motor skill and/or cognitive performance in athletes. Dietary constituents discussed include branched-chain amino acids, caffeine, carbohydrate, cocoa flavanols, Gingko biloba, ginseng, guarana, Rhodiola rosea, sage, L-theanine, theobromine, and tyrosine. Although this is not an exhaustive list, these are perhaps the most researched dietary constituents. Caffeine and carbohydrate have the greatest number of published reports supporting their ability to enhance acute motor skill and cognitive performance in athletes. At this time, there is insufficient published evidence to substantiate the use of any other dietary constituents to benefit sports-related motor skill or cognitive performance. The optimal dose and timing of caffeine and carbohydrate intake promoting enhanced motor skill and cognitive performance remain to be identified. Valid, reliable, and sensitive batteries of motor skills and cognitive tests should be developed for use in future efficacy studies., (© 2014 International Life Sciences Institute.)

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.

Background: We developed a digital dietary analysis tool for athletes (DATA) using a modified 24-h recall method and an integrated, customized nutrient database. The purpose of this study was to assess DATA's validity and relative validity by measuring its agreement with registered dietitians' (RDs) direct observations (OBSERVATION) and 24-h dietary recall interviews using the USDA 5-step multiple-pass method (INTERVIEW), respectively., Methods: Fifty-six athletes (14-20 y) completed DATA and INTERVIEW in randomized counter-balanced order. OBSERVATION (n = 26) consisted of RDs recording participants' food/drink intake in a 24-h period and were completed the day prior to DATA and INTERVIEW. Agreement among methods was estimated using a repeated measures t-test and Bland-Altman analysis., Results: The paired differences (with 95% confidence intervals) between DATA and OBSERVATION were not significant for carbohydrate (10.1%, -1.2-22.7%) and protein (14.1%, -3.2-34.5%) but was significant for energy (14.4%, 1.2-29.3%). There were no differences between DATA and INTERVIEW for energy (-1.1%, -9.1-7.7%), carbohydrate (0.2%, -7.1-8.0%) or protein (-2.7%, -11.3-6.7%). Bland-Altman analysis indicated significant positive correlations between absolute values of the differences and the means for OBSERVATION vs. DATA (r = 0.40 and r = 0.47 for energy and carbohydrate, respectively) and INTERVIEW vs. DATA (r = 0.52, r = 0.29, and r = 0.61 for energy, carbohydrate, and protein, respectively). There were also wide 95% limits of agreement (LOA) for most method comparisons. The mean bias ratio (with 95% LOA) for OBSERVATION vs. DATA was 0.874 (0.551-1.385) for energy, 0.906 (0.522-1.575) for carbohydrate, and 0.895(0.395-2.031) for protein. The mean bias ratio (with 95% LOA) for INTERVIEW vs. DATA was 1.016 (0.538-1.919) for energy, 0.995 (0.563-1.757) for carbohydrate, and 1.031 (0.514-2.068) for protein., Conclusion: DATA has good relative validity for group-level comparisons in athletes. However, there are large variations in the relative validity of individuals' dietary intake estimates from DATA, particularly in athletes with higher energy and nutrient intakes. DATA can be a useful athlete-specific, digital alternative to conventional 24-h dietary recall methods at the group level. Further development and testing is needed to improve DATA's validity for estimations of individual dietary intakes.

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.