Upper and lower body sensitivity to cold at rest and during exercise

Upper and lower body sensitivity to cold at rest and during exercis

Porous silicon biosensor for the detection of autoimmune diseases

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A comparison of galvanic skin conductance and skin wettedness as indicators of thermal discomfort during moderate and high metabolic rates

The relationship between local thermal comfort, local skin wettedness (w) and local galvanic skin conductance (GSC) in four body segments during two different exercise intensities was compared in 10 males. In a balanced order, participants walked at 35% VO for 45min (WALK) (29.0±1.9°C, 29.8±3.6% RH, no wind) in one test and in a separate test ran at 70% VO for 45min (RUN) (26.2±2.1°C, 31.1±7.0% RH, no wind). During both tests, participants wore a loose fitting 100% polyester long sleeve top and trouser ensemble with a low resistance to heat and vapour transfer (total thermal resistance of 0.154mKW and total water vapour resistance of 35.9mPaW). w, change from baseline in GSC (δGSC) and local thermal comfort were recorded every 5min. The results suggest that both w and δGSC are strong predictors of thermal comfort during the WALK when sweat production is low and thermal discomfort minimal (r>0.78 and r>0.71, respectively). Interestingly, during the RUN w plateaued at ~0.6 to 0.8 due to the high sweat production, whilst δGSC gradually increased throughout the experiment. δGSC had a similar relationship with thermal comfort to w during the RUN (r>0.95 and r>0.94, respectively). Despite the strength of these relationships, the ability of w to predict local thermal comfort accurately dramatically reduces in the exponential part of the curve. In a situation of uncompensated heat stress such as high metabolic rate in hot climate, where sweat production is high, δGSC shows to be a better predictor of local thermal comfort than w. The w data shows regional differences in the threshold which triggers local discomfort during the WALK than RUN; lower values are found for upper arms (0.22±0.03 and 0.28 ±0.22) and upper legs (0.22±0.11 and 0.22±0.10), higher values for upper back (0.30±0.12 and 0.36 ±0.10) and chest (0.27±0.10 and 0.39 ±0.32), respectively. However, no regional differences in the threshold of discomfort are found in the {increment}GSC data. Instead, the data suggests that the degree of discomfort experienced appears to be related to the amount of sweat within and around the skin (as indirectly measured by δGSC) at each body site. © 2013 Elsevier Ltd

Body mapping of thermoregulatory and perceptual responses of males and females running in the cold

Thermoregulatory parameters during exercise are typically reported as global responses (T and mean T). In contrast, this study investigated regional skin temperatures (T) over the body, in relation to regional skinfold thickness and regional perceptual responses for both sexes using a body-mapping approach. Nine males and nine females, of equivalent fitness, minimally clothed, ran for 40min at 70% VO2max in a 10°C, 50%rh, 2.8ms air velocity environment. T was recorded by infrared thermography and processed to obtain population-averaged body maps. Rectal temperature and heart rate were monitored continuously throughout the running trial. Skinfold thickness was obtained for 24 sites and thermal sensation votes for 11 body regions.Males and females had similar rectal temperature, heart rate and regional sensations. Whole-body maps of T highlighted the significantly lower regional T for females (-1.6°C overall, p<0.01). However, the distribution of T across the body was similar between sexes and this was not correlated with the distribution of skinfold thickness, except for the anterior torso. On the other hand, regional thermal sensation votes across the body were correlated with T distribution during exercise (females: r=0.61, males: r=0.73, p<0.05), but not at rest.Our thermographic results demonstrate the similar T distribution for active males and females during submaximal running in the cold, though shifted to a lower mean value for females. This T distribution was associated with regional sensations but not with local fat thickness. The described body-mapping approach can have implications in physiological modelling and clothing design. © 2013 Elsevier Ltd

Female thermal sensitivity to hot and cold during rest and exercise

Regional differences in thermal sensation to a hot or cold stimulus are often limited to male participants, in a rested state and cover minimal locations. Therefore, magnitude sensation to both a hot and cold stimulus were investigated during rest and exercise in 8 females (age: 20.4±1.4years, mass: 61.7±4.0kg, height: 166.9±5.4cm, VO2max: 36.8±4.5ml·kg-1·min-1). Using a repeated measures cross over design, participants rested in a stable environment (22.3±0.9°C, 37.7±5.5% RH) whilst a thermal probe (25cm2), set at either 40°C or 20°C, was applied in a balanced order to 29 locations across the body. Participants reported their thermal sensation after 10s of application. Following this, participants cycled at 50% VO2max for 20min and then 30% VO2max whilst the sensitivity test was repeated. Females experienced significantly stronger magnitude sensations to the cold than the hot stimulus (5.5±1.7 and 4.3±1.3, p<0.05, respectively). A significant effect of location was found during the cold stimulation (p<0.05). Thermal sensation was greatest at the head then the torso and declined towards the extremities. No significant effect of location was found in response to the hot stimulation and the pattern across the body was more homogenous. In comparison to rest, exercise caused a significant overall reduction in thermal sensation (5.2±1.5 and 4.6±1.7, respectively, p<0.05). Body maps were produced for both stimuli during rest and exercise, which highlight sensitive areas across the body

Cognitive, physical and emotional determinants of activities of daily living in nursing home residents—a cross-sectional study within the PROCARE-project

Background Interdependencies of health, fitness, cognition, and emotion can promote or inhibit mobility. This study aimed to analyse pathways and interactions between individual subjective and objective physical performance, cognition, and emotions with activities of daily living (ADLs) as mobility indicators in multimorbid nursing home residents. Methods The study included $n$ = 448 (77.1% females, age = 84.1 ± 7.8 years) nursing home residents. To describe the participant\u27s demographics, frailty, number of falls, and participating institutions\u27 socioeconomic status (SES) were assessed. ADLs were measured with the Barthel Index (BI; dependent variable). Independent variables included objective physical performance, subjective physical performance, cognition, and emotions. A structural equation model (SEM) with maximum likelihood estimation was conducted with AMOS. Direct and indirect effects were estimated using standardized coefficients (significance level of 0.05). Results Indices showed (Chi$^2$(148) = 217, PCMIN/DF = 1.47; p < .001; Comparative Fit Index = .940; Tucker Lewes Index = .902, RMSEA = .033) that the model fitted the data adequately. While there was no direct association between emotions, subjective physical performance, and ADLs, objective physical performance and cognition predicted higher ADLs (p < .01). Emotions had a strong relationship with subjective physical performance, and cognition had a moderate relationship with objective physical performance. Discussion and conclusion Objective performance and cognition predicted higher functional status, as expressed by higher BI scores. ADLs, such as mobility, dressing, or handling tasks, require motor and cognitive performance. Subjective performance is an important predictor of ADLs and is only partly explained by objective performance, but to a large extent also by emotions. Therefore, future interventions for nursing home residents should take a holistic approach that focuses not only on promoting objective physical and cognitive performance but also on emotions and perceived physical performance

Sweat from gland to skin surface: Production, transport and skin absorption

By combining galvanic skin conductance (GSC), stratum corneum hydration (HYD) and regional surface sweat rate (RSR) measurements at the arm, thigh, back and chest, we closely monitored the passage of sweat from gland to skin surface. Through a varied exercise-rest protocol, sweating was increased slowly and decreased in 16 male and female human participants (25.3 ± 4.7 yrs, 174.6 ± 10.1 cm, 71.3 ± 12.0 kg, 53.0 ± 6.8 ml∙kg∙min-1). ∆GSC and HYD increased prior to RSR, indicating pre-secretory sweat gland activity and skin hydration. ∆GSC and HYD typically increased concomitantly during rest in a warm environment (30.1 ± 1.0°C, 30.0 ± 4.7% RH) and only at the arm did ∆GSC increase prior to an increase in HYD. HYD increased prior to RSR, before sweat was visible on the skin, but not to full saturation, contradicting earlier hypotheses. Maximal skin hydration did occur, as demonstrated by a plateau in all regions. Post exercise rest resulted in a rapid decrease in HYD and RSR but a delayed decline in ∆GSC. Evidence for reabsorption of surface sweat into the skin following a decline in sweating, as hypothesized in the literature, was not found. This suggests that skin surface sweat, after sweating is decreased, may not diffuse back into the dermis, but is only evaporated. These data, showing distinctly different responses for the three measured variables, provide useful information about the fate of sweat from gland to surface that is relevant across numerous research fields (e.g. thermoregulation, dermatology, ergonomics and material design)

A multicomponent exercise intervention to improve physical functioning, cognition and psychosocial well-being in elderly nursing home residents: a study protocol of a randomized controlled trial in the PROCARE (prevention and occupational health in long-term care) project

Background Older adults, who are living in nursing homes that provide a high level of long-term nursing care, are characterized by multimorbidity and a high prevalence of dependency in activities of daily living. Results of recent studies indicate positive effects of structured exercise programs during long-term care for physical functioning, cognition, and psychosocial well-being. However, for frail elderly the evidence remains inconsistent. There are no evidence-based guidelines for exercises for nursing home residents that consider their individual deficits and capacities. Therefore, high-quality studies are required to examine the efficacy of exercise interventions for this multimorbid target group. The purpose of this study is to determine the feasibility and efficacy of a multicomponent exercise intervention for nursing home residents that aims to improve physical and cognitive functioning as well as quality of life. Methods A two-arm single-blinded multicenter randomized controlled trial will be conducted, including 48 nursing homes in eight regions of Germany with an estimated sample size of 1120 individuals. Participants will be randomly assigned to either a training or a waiting time control group. For a period of 16 weeks the training group will meet twice a week for group-based sessions (45–60 min each), which will contain exercises to improve physical functioning (strength, endurance, balance, flexibility) and cognitive-motor skills (dual-task). The intervention is organized as a progressive challenge which is successively adapted to the residents’ capacities. Physical functioning, cognitive performance, and quality of life will be assessed in both study groups at baseline (pre-test), after 16-weeks (post-treatment), and after 32-weeks (retention test, intervention group only). Discussion This study will provide information about the efficacy of a multicomponent exercise program in nursing homes (performance, recruitment). Results from this trial will contribute to the evidence of multicomponent exercises, which specifically focus on cognitive-motor approaches in the maintenance of mental and physical functioning. In addition, it will help to encourage older adults to actively engage in social life. Furthermore, the findings will lead to recommendations for health promotion interventions for frail nursing home residents. Trial registration The trial was prospectively registered at DRKS.de with the registration number DRKS00014957 on October 9, 2018

Physical activity and health promotion for nursing staff in elderly care: a study protocol for a randomised controlled trial

Introduction Nursing staff is burdened by high workload and stress. Furthermore, heavy lifting, as well as transferring nursing home residents, cause lumbar tissue damage and back pain. Exercise intervention studies to reduce work-related problems are rare and the evidence for efficacy of studies among nurses is limited. Studies including targeted analysis of requirements are necessary to generate effective recommendations and tailored interventions for health promotion programmes. The purpose of this multicentred intervention study is to identify work-related problems, to implement health promotion programmes and to evaluate their effectiveness. Methods and analysis A randomised controlled trial will be conducted, including a total of 48 nursing home facilities in eight regions of Germany with an estimated sample size of 700 nurses. Standardised ergonomics and posture training (10 weeks, once a week for 20–30 min) and subsequently, back-fitness training (12 weeks, once a week for 45–60 min) will be administered. Following the implementation of standardised health promotion programmes, further demand-oriented interventions can be implemented. The perceived exposure to work-related demands, work-related pain in different parts of the body, health-related quality of life, perceived stress, work-related patterns of behaviour and experience, presentism behaviour, work environment as well as general needs and barriers to health promotion, will be assessed at baseline (pre-test), at 10 weeks (post-test, after ergonomics training), at 22 weeks (post-test, after back-fitness training) and at 34 weeks of the programme (follow-up). Ethics and dissemination The study was reviewed and approved by the local ethics committee of the University of Hamburg (AZ: 2018_168). The results of the study will be published in open-access and international journals. Furthermore, the results will be presented in the participating nursing homes and at national and international conferences

Female Thermal Sensitivity to Hot and Cold During Rest and Exercise

Regional differences in thermal sensation to a hot or cold stimulus are often limited to male participants, in a rested state and cover minimal locations. Therefore, magnitude sensation to both a hot and cold stimulus were investigated during rest and exercise in 8 females (age: 20.4 ± 1.4 years, mass: 61.7 ± 4.0 kg, height: 166.9 ± 5.4 cm, VO2max: 36.8 ± 4.5 ml·kg− 1·min− 1). Using a repeated measures cross over design, participants rested in a stable environment (22.3 ± 0.9 °C, 37.7 ± 5.5% RH) whilst a thermal probe (25 cm2), set at either 40 °C or 20 °C, was applied in a balanced order to 29 locations across the body. Participants reported their thermal sensation after 10 s of application. Following this, participants cycled at 50% VO2max for 20 min and then 30% VO2max whilst the sensitivity test was repeated. Females experienced significantly stronger magnitude sensations to the cold than the hot stimulus (5.5 ± 1.7 and 4.3 ± 1.3, p < 0.05, respectively). A significant effect of location was found during the cold stimulation (p < 0.05). Thermal sensation was greatest at the head then the torso and declined towards the extremities. No significant effect of location was found in response to the hot stimulation and the pattern across the body was more homogenous. In comparison to rest, exercise caused a significant overall reduction in thermal sensation (5.2 ± 1.5 and 4.6 ± 1.7, respectively, p < 0.05). Body maps were produced for both stimuli during rest and exercise, which highlight sensitive areas across the body