The Effects of Increased Electrolyte Concentrations on Net Body Fluid

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Description
Dehydration during and after exercise is prevalent in athletes. Due to a thirst mechanism that does not entirely replenish total body water lost during exercise, it is crucial to rehydrate efficiently with sufficient fluids and electrolytes to retain fluid intake.

Dehydration during and after exercise is prevalent in athletes. Due to a thirst mechanism that does not entirely replenish total body water lost during exercise, it is crucial to rehydrate efficiently with sufficient fluids and electrolytes to retain fluid intake. The study aimed to observe the effectiveness of rehydration with different commercially available drinks and plain water. The rehydration was assessed over 4 hours after a 2% exercise-induced dehydration in the heat. Rehydration was equal to 150% of fluid loss via exercise and was administered in four equal doses during the first 60 minutes of the rehydration period. The average exercise-induced dehydration was 2.11 ± 0.4%. The high sodium and potassium-containing drink, GoodSport, had significantly better rehydration at the four-hour time point (-0.44 ± .21) than in Gatorade (-0.71 ± 0.16; P = 0.0273), Body Armor (-1.00 ± 0.5; P < 0.0001), and water (-0.88 ± 0.39; P = 0.0015). Similarly, GoodSport resulted in lower urinary output than the other drinks. Results from this study indicate that the intake of a high sodium and potassium-containing sports drink after exercise improves net fluid balance more than drinks with lower electrolyte concentrations.
Date Created
2023
Agent

Ventilated Capsules for Sweat Evaporation Rate Measurement

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Description
Sweat evaporation is fundamental to human thermoregulation, yet our knowledge of the microscale sweat droplet evaporation dynamics is very limited. To study sweat droplet evaporation, a reliable way to measure sweat evaporation rate from skin and simultaneously image the droplet

Sweat evaporation is fundamental to human thermoregulation, yet our knowledge of the microscale sweat droplet evaporation dynamics is very limited. To study sweat droplet evaporation, a reliable way to measure sweat evaporation rate from skin and simultaneously image the droplet dynamics through midwave infrared thermography (MWIR) or optical coherence tomography (OCT) is required. Ventilated capsule is a common device employed for measuring sweat evaporation rates in physiological studies. However, existing designs of ventilated capsules with cylindrical flow chambers create unrealistic flow conditions that include flow separation and swirling. To address this problem, this thesis introduces a ventilated capsule with rectangular sweat evaporation area preceded by a diffuser section with geometry based on wind tunnel design guidelines. To allow for OCT or MWIR imaging, a provision to install an acrylic or a sapphire window directly over the exposed skin surface being measured is incorporated in the design. In addition to the capsule, a simplified artificial sweating surface that can supply water in a filmwise, single or multiple droplet form was developed. The performance of the capsule is demonstrated using the artificial sweating surface along with example MWIR imaging.
Date Created
2023
Agent

Assessing the Efficacy of Various Practical Cooling Protocols in Athletes

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Description
The human body has temperature-regulating mechanisms working to maintain body core temperature around 37°C. This ensures optimal bodily function. Disruption to core temperature however, initiates a cascade of events to return to baseline. The objective of this study is to

The human body has temperature-regulating mechanisms working to maintain body core temperature around 37°C. This ensures optimal bodily function. Disruption to core temperature however, initiates a cascade of events to return to baseline. The objective of this study is to evaluate the efficacy of cooling strategies to induce the fastest reductions in core temperature. The study was set up as a randomized field study. Core temperature was measured using an E-Celsius core temperature capsule. Environmental conditions were measured using a Kestrel heat stress tracker. Following completion of a heat-stress protocol, participants underwent one of the four randomized cooling protocols. These cooling protocols consisted of: 1) wearing an ice vest (18°C), 2) applying an icy towel directly to the back of the neck (24°C) in combination with hand/forearm water immersion (15°C), 3) a combination of ice vest, icy towel and hand/forearm water immersion, or 4) sitting in a thermoneutral room (20°C). In all cooling interventions, participants consumed 16oz of an ice slurry (0°C) within 10 minutes of the initiation of the protocol. The control group consumed only room temperature water- ad libitum. A total of 10 active males (25 ± 3 years old) reported no difference between baseline body core temperatures after each heating intervention (P=0.23). Average core temperature and heart rate differed, though not statistically significant between treatments (P>0.05). No significant differences were noted between cooling rates (P=0.51). Skin temperature (Tsk) average and decrement was found to be statistically significant (P<0.001).
Date Created
2022
Agent

Tap Water Consumption and Perceptions in US Latinx Adults

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Description
The purpose of this investigation was to evaluate the influence of tap water safety perceptions on plain water intake (PWI) and hydration status in US Latinx adults. Participants (n=492; age, 28±7 y; 37.4% female) completed an Adapted Survey of Water

The purpose of this investigation was to evaluate the influence of tap water safety perceptions on plain water intake (PWI) and hydration status in US Latinx adults. Participants (n=492; age, 28±7 y; 37.4% female) completed an Adapted Survey of Water Issues in Arizona and household watersecurity experience-based scales. A sub-sample (n=55; age, 33±14 y; body mass index, 27.77±6.60 kg·m2) completed dietary recalls on two weekdays and one weekend day via Automated Self-Administered 24-hour Dietary Assessment Tool to determine average PWI and total water intake (TWI). A 24-h urine sample was collected on one recall day and analyzed for urine osmolality (UOsm). Binary logistic regression determined odds ratios (OR) for the odds of perceiving tap water to be unsafe. Hierarchical linear regression was employed with 24-h UOsm and PWI as primary outcomes for the sub-sample. Overall, 51.2% of all participants and 52.7% of the sub-sample mistrust their tap water safety. The odds of mistrusting tap water were significantly greater (P<0.05) for each additional favorable perception of bottled over tap water (OR=1.94, 95% CI=1.50, 2.50), each additional negative home tap water experience (OR=1.32, 95% CI=1.12, 1.56), each additional use of alternatives and/or modifications to home tap water (OR=1.25, 95% CI=1.04, 1.51), and decreased water quality and acceptability (OR=1.21, 95% CI=1.01, 1.45). The odds of mistrusting tap water were significantly lower (P<0.05) for those whose primary source of drinking water is the public supply (municipal) (OR=0.07, 95% CI=0.01, 0.63) and for those with decreased water access (OR=0.56, 95% CI=0.48, 0.66). There were no differences (n=55, P>0.05) in TWI (2,678±1,139 mL), PWI (1,357±971), or 24-h UOsm (460±234 mosm·kg-1). Tap water safety perceptions did not significantly explain variance in PWI or 24-h UOsm (P > 0.05). In conclusion, Latinx mistrust in tap water safety is prevalent. Mistrust appears to be influenced by organoleptic perceptions and to lead to reliance on alternatives to the home drinking water system. Perceptions of tap water safety do not appear to be related to PWI, TWI, or hydration status in Latinx adults.
Date Created
2022
Agent

A Single Combined Active and Passive Isothermic Heating Protocol Results in a Similar Core Temperature Response as Exercise Alone in Hot Conditions

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Description
Heat acclimatization can be induced by targeting a core temperature 38.5°C for at least 60 minutes per day lasting 5 to 21 days, complementary to normal exercise activity. However, consistently meeting this threshold on consecutive days may be difficult for

Heat acclimatization can be induced by targeting a core temperature 38.5°C for at least 60 minutes per day lasting 5 to 21 days, complementary to normal exercise activity. However, consistently meeting this threshold on consecutive days may be difficult for athletes. The objective of this study was to evaluate the efficacy of four single-bout heating protocols to reach a core temperature 38.5°C. The study was set up as a non-randomized field study, factoring in the September-October outdoor desert conditions, Tempe, AZ, USA. Environmental conditions were measured using a Kestrel heat stress tracker. Protocols were constituted out of 3 elements: PAS – passive heat exposure in a tent (54±1°C), EH - exercise in hot condition with high intensity interval training (HIIT) outdoors in the heat in a tent with a ventilator (43±1°C), EM – exercise in moderate conditions with HIIT indoors (22±0.4°C). All participants performed protocols in the following order: 1) PAS 60-min; 2) EH-PAS (EH 30-min + PAS 30-min); 3) EH 60-min, and 4) EM 60-min. A cycle ergometer was used for HIIT (2-min warm-up followed by 7x2-min sprints with 2-min relative rest between sprints during the first 30 min and stationary cycling for the second 30 min), with a self-selected workload at 80-100 rpm and similar heart rate (HR) response during exercise testing for EH: 146±10, EM: 142±13, and EH-PAS: 142±13 (P>0.05). A total of 10 active male students (25±3 years old) reported no difference between protocols for baseline Tc (P=0.37) and HR (P=0.28). During the first 30-min, Tc was significantly different between protocols (average ranging from 37.3-37.6°C, P=0.01), but from a practical perspective, differences were limited. During the second 30-min session, the Tc for EH (38.5±0.4°C) and EH-PAS (38.6±0.4°C) were significantly higher from EM (38.1±0.4°C) and PAS alone (37.8±0.4°C), P<0.001. The average HR (bpm) was significantly lower in PAS (110±17) and EH (136±13) during the second half of the protocols compared to the EH (151±10) and EM (149±16), P<0.001. In conclusion, exercise alone vs. a combination of exercise and passive heating in hot conditions resulted both in a body temperature 38.5°C, but the combination was more efficient since participants exercised for only 30-minutes.
Date Created
2022
Agent

The Impact of Adequate Water Intake on Exercise Performance and Mood in Women and Men

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Description
The purpose of this study was to evaluate the impact of improved hydration on endurance performance and mood in physically active adults. Participants (n = 72; age, 21.0 ± 3.0; 22.2% female) completed two two-mile run trials separated by exactly

The purpose of this study was to evaluate the impact of improved hydration on endurance performance and mood in physically active adults. Participants (n = 72; age, 21.0 ± 3.0; 22.2% female) completed two two-mile run trials separated by exactly a week. Before each trial, participants provided a urine sample from the day before the run and a sample from the morning of the run. These samples were analyzed for urine osmolality (UOsm), urine specific gravity (USG), and urine color (Ucol). UOsm and USG levels determined if the participants were placed in either the euhydrated or underhydrated group after the first trial. Those assigned to the euhydrated group were instructed to maintain their current fluid intake levels and those in the underhydrated group were instructed to increase fluid intake levels before the second trial. However, results were grouped by if they improved or maintained their hydration or not. The subjects also completed a Profile of Mood States (POMS) questionnaire before and after each trial to determine mood. Based on conditioning requirements for group assignment, 38% of subjects were classified as underhydrated. There were significant differences between the two trials for both subjects that improved and worsened their hydration in UOsm, USG, Ucol, and thirst (P < 0.05). The group with improved hydration ran -15 ± 67 sec faster in the second trial, while the group that worsened hydration ran 4 ± 26 sec slower in the second trial. When these differences were compared between the two groups with a t-test, there was a trend for statistical differences with a one-way t-test analysis (P = 0.06). When results were split by sex no statistically significant differences were observed (male: -10.8 ± 63.6 sec; female: -29.4 ± 94.8 sec; P > 0.05). Improved hydration did not result in statistically significant difference in TMD or any of the individual mood sub-scales for either group for both males and females (P > 0.05). In conclusion, increased fluid intake to optimize hydration status may affect endurance exercise in young, healthy adults in a two-mile run, but no effect was seen on mood.
Date Created
2022
Agent

Effects of Increased Water Intake on Uropathogenic Bacterial Activity of Underhydrated Menstruating Premenopausal Females

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Description
Urinary tract infections (UTIs) disrupt military women’s service obligations and health. Females are more susceptible to UTIs due to their unique anatomical features and hormone fluctuations affecting vaginal flora. During phase 1 of the menstrual cycle (onset of bleeding, menstrual

Urinary tract infections (UTIs) disrupt military women’s service obligations and health. Females are more susceptible to UTIs due to their unique anatomical features and hormone fluctuations affecting vaginal flora. During phase 1 of the menstrual cycle (onset of bleeding, menstrual cycle days 1-5), estrogen levels significantly decrease and inhibit the growth of lactobacilli, good bacteria that are essential in warding off harmful bacteria and infections, particularly pathogens of UTIs. To reduce UTI onset, it is recommended to frequently urinate with sufficient urine void volume to facilitate washing out harmful bacteria from the bladder and urethra. While menstruating, increased fluid consumption to support urination frequency and void volume may be critical, as the urethra and urinary tract are more predisposed to pathogenic bacteria found. Yet, there is a lack of research investigating the impact of hydration on urinary tract health during menstruation. The study sought to examine the effects of increased water fluid intake on the uropathogenic bacterial activity of underhydrated menstruating premenopausal females. Thirteen females underwent a 2x2 randomized crossover trial to evaluate the effectiveness of a) additional 1.89 L of water fluid intake and b) maintain habitual fluid intake on two subsequent phase 1 menses. At each phase 1 menses, fluid intake was gathered on days 2 and 5 to determine the fluid amount consumed. First-morning urinations on days 3 and 6 assessed urogenital bacterial activity. Combining data collection days 2 and 5 per intervention (INT) and control (CON), the mean±SD for total fluid intake was INT 2.99±1.05 and CON 1.85±0.89, resulting in a 62% increase, p< 0.001, η2= 0.459. For days 2 and 5, a 48% and 80% increase in total fluid in from CON to INT was found, ps< 0.01. However, only four cultures detected uropathogenic bacteria from four participants, with no patterns between conditions or days, making it difficult to determine the effectiveness of the intervention. Though the intervention results were undetermined, military women’s hydration, menstruation, and urinary tract health remain prominent health concerns. Efforts to assess their fluid consumption and urination behaviors during menstruation and UTI risks are warranted.
Date Created
2022
Agent

Health Impacts of Water and Sanitation Insecurity in US Colonias: A Scoping Literature Review

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Description

U.S. border colonias, otherwise known as Disadvantaged Unincorporated Communities, are rural settlements along the U.S. Mexico border with substandard housing conditions. Colonia residents often face inadequate access to necessities such as appropriate shelter, septic and sewer systems, and potable water.

U.S. border colonias, otherwise known as Disadvantaged Unincorporated Communities, are rural settlements along the U.S. Mexico border with substandard housing conditions. Colonia residents often face inadequate access to necessities such as appropriate shelter, septic and sewer systems, and potable water. Water insecurity in colonias poses a particularly difficult challenge for residents who require clean water not only for consumption, but also household use in sanitation and hygienic practices. As of 2015, an estimated 30% of over five million US colonia residents lack access to clean drinking water, resulting in health complications and unsanitary living conditions. Preliminary health data collected indicates that due to water insecurity, colonia residents are more likely to contract gastrointestinal disease, be exposed to carcinogenic compounds from contaminated water, and experience psychosocial distress. Yet more comprehensive research needs to be conducted to understand the full breadth of the public health issue. A scoping review on water insecurity in colonias has not been completed before and could be beneficial in informing policymakers and other stakeholders on the severity of the situation while advising possible solutions.

Date Created
2021-12
Agent

Behavior Influencing Acute Hydration Status of Recreational Hikers in Hot and Moderate Weather Conditions

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Description
Annually, more than 200 hikers are rescued in the greater Phoenix area. This study examined behavior influencing acute hydration status in hot (HOT) and moderate (MOD) climates, by examining fluid planning and decision making in combination with an educational video.

Annually, more than 200 hikers are rescued in the greater Phoenix area. This study examined behavior influencing acute hydration status in hot (HOT) and moderate (MOD) climates, by examining fluid planning and decision making in combination with an educational video. A total of n=115 hikers completed self-paced hikes, n=56 hikers completed the hike in a HOT condition (wet bulb globe temperature [WBGT]=24.84°C) and n=59 hikers completed the hike in a MOD condition (WBGT=8.28°C). Real food and fluid behavior allowed participants to freely select the amount of food and fluid brought on the hike and intake was ad libitum. The following heat stress indicators were all significantly higher in the HOT condition compared to MOD condition (HOT median, MOD median; p-value): hike duration (1.48, 1.20; p<0.01), energy expenditure (561, 408, p<0.01), sweat rate (776, 465, p<0.01), and session rating of perceived exertion (RPE) scores (1177, 732, p<0.01). After watching a 3-minute hydration education video, and the opportunity to stock up on extra fluid, 54% of participants carried sufficient fluid in the HOT condition to meet their needs compared to 81% of participants in the MOD condition. However, only 23% of participants in the HOT condition consumed sufficient fluid to make up for fluid lost through sweating compared to 33% in the MOD condition. More than half of participants in the HOT condition (59%) and the MOD condition (76%) did not stock up on extra fluid after education. These results demonstrate that hikers did not consume sufficient fluids to meet their needs while hiking, especially in a hot climate. They also show heat stress negatively affected hikers’ performance measures. More research is required to assess the feasibility and efficacy of hydration related education videos at trailheads.
Date Created
2021
Agent

Intrinsic Fatigue & Its Relation to Workload

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Description
The study aimed to determine the relationship of subjective perception of wellness (Intrinsic Fatigue) and Global Positioning Satellite derived workload amongst elite high school soccer players. Twenty-nine (16.4 ± 1.54 years) male participants completed a mobile app-based wellness questionnaire comprising

The study aimed to determine the relationship of subjective perception of wellness (Intrinsic Fatigue) and Global Positioning Satellite derived workload amongst elite high school soccer players. Twenty-nine (16.4 ± 1.54 years) male participants completed a mobile app-based wellness questionnaire comprising of 6 subjective markers prior to 10 workload variables being measured by STATSports 10Hz GPS units later that same day. Only instances where both wellness and GPS reports qualified for analyses (N=231 exposures). No significant differences were reported in reported wellness within- or between-weeks (p > 0.05) with average Effect Sizes (ES) ranging from 0.001 to 0.15. Total Distance (TD) was significantly different (p < 0.05) within week. All GPS variables except TD and Distance per Minute (DpM) were significantly different (p < 0.05) between-weeks. Average GPS ES sizes ranged from 0.02 to 0.58. Wellness and GPS or it’s ESs were not correlated, with correlations ranging from -1.000 to 0.207. The results suggest monitoring of GPS reports to be a practical method of monitoring variation in player workload but does not support subjective questionnaires as a means of monitoring player wellness reflecting these workload variations in youth populations.
Date Created
2020
Agent