scholarly journals The impact of heat on human physical work capacity; Part III: the impact of solar radiation varies with air temperature, humidity, and clothing coverage.

2021 ◽  
Author(s):  
Josh Foster ◽  
James W Smallcombe ◽  
Simon G Hodder ◽  
Andreas D Flouris ◽  
Lars Nybo ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Work Productivity ◽  
Work Capacity ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Adult Males ◽  
Cumulative Energy ◽  
Heat Effects ◽  
The Impact

It is well-known that heat impacts human labour/physical work capacity (PWC), but systematic evaluations of solar radiation (SOLAR) effects and the interaction with air temperature and humidity levels and clothing are lacking, as most lab-studies are conducted in semi-nude subjects without radiation or only in a single climatic condition. Due to the high relevance of SOLAR in various occupations, this study quantified how SOLAR interacts with clothing and other primary environmental factors (air temperature/humidity) of importance to determine PWC in the heat. The data allowed the development of a SOLAR correction factor for predicting PWC in major outdoor industries. Fourteen young adult males (7 wearing a standardised work coverall (0.9 Clo), 7 with shorts and trainers (0.3 Clo) walked for 1-hour at a fixed heart rate of 130 b∙min-1, in seven combinations of air temperature (25 to 45 Celsius) and relative humidity (20 or 80%), with and without SOLAR (800 W/m2 from solar lamps). Cumulative energy expenditure in the heat, relative to the work achieved in a cool reference condition, was used to determine PWC%. Skin temperature was the primary determinant of PWC in the heat. In dry climates with exposed skin (0.3 Clo), SOLAR caused PWC to decrease exponentially with rising air temperature, whereas work coveralls (0.9 Clo) negated this effect. In humid conditions, the SOLAR-induced reduction in PWC was consistent and linear across all levels of air temperature, and clothing conditions. WBGT and UTCI based prediction equations of PWC represented SOLAR correctly. For heat indices not intrinsically accounting for SOLAR, correction factors are provided enabling forecasting of heat effects on work productivity.

scholarly journals Quantifying the impact of heat on human physical work capacity; part III: the impact of solar radiation varies with air temperature, humidity, and clothing coverage

2021 ◽  
Author(s):  
Josh Foster ◽  
James W. Smallcombe ◽  
Simon Hodder ◽  
Ollie Jay ◽  
Andreas D. Flouris ◽  
...  
Keyword(s):  
Heat Stress ◽  
Solar Radiation ◽  
Air Temperature ◽  
Work Capacity ◽  
Stress Index ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Heat Effects ◽  
Heat Stress Index ◽  
The Impact

AbstractHeat stress decreases human physical work capacity (PWC), but the extent to which solar radiation (SOLAR) compounds this response is not well understood. This study empirically quantified how SOLAR impacts PWC in the heat, considering wide, but controlled, variations in air temperature, humidity, and clothing coverage. We also provide correction equations so PWC can be quantified outdoors using heat stress indices that do not ordinarily account for SOLAR (including the Heat Stress Index, Humidex, and Wet-Bulb Temperature). Fourteen young adult males (7 donning a work coverall, 7 with shorts and trainers) walked for 1 h at a fixed heart rate of 130 beats∙min−1, in seven combinations of air temperature (25 to 45°C) and relative humidity (20 or 80%), with and without SOLAR (800 W/m2 from solar lamps). Cumulative energy expenditure in the heat, relative to the work achieved in a cool reference condition, was used to determine PWC%. Skin temperature was the primary determinant of PWC in the heat. In dry climates with exposed skin (0.3 Clo), SOLAR caused PWC to decrease exponentially with rising air temperature, whereas work coveralls (0.9 Clo) negated this effect. In humid conditions, the SOLAR-induced reduction in PWC was consistent and linear across all levels of air temperature and clothing conditions. Wet-Bulb Globe Temperature and the Universal Thermal Climate Index represented SOLAR correctly and did not require a correction factor. For the Heat Stress Index, Humidex, and Wet-Bulb Temperature, correction factors are provided enabling forecasting of heat effects on work productivity.

scholarly journals Physical Work Capacity of Young Greco-Roman Wrestlers on the Background of their Somatic Development

2018 ◽  
Vol 3 (57) ◽  
Author(s):  
Wladyslaw Jagiello ◽  
Wlodzimierz Tkaczuk
Keyword(s):  
Body Mass ◽  
Work Capacity ◽  
High Rate ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Mean Values ◽  
Functional Changes ◽  
Somatic Development ◽  
Greco Roman ◽  
The Impact

On the basis of studies of 210 Greco-Roman wrestlers aged 11—18 the impact of training loads and sports selectionin the above sports event upon physical development and general work capacity of young athletes have beendetermined.Besides, age dynamics of changes of the major somatic indices (body length and mass) as well as physical workcapacity at the stage of initial and basic sports preparation has been determined.The studies have resulted in the determination of specific for Greco-Roman wrestlers changes in the examined indicesand development of evaluation scale of general physical work capacity.On the basis of findings we may conclude that Greco-Roman wrestling has a positive influence on developing body.In most cases mean values of examined somatic indices exceed those of children not engaged in sports as well aschildren practising other sports events. This sports event may be considered as a good means stimulating physicaldevelopment of children and youth.The age of 11—15 has turned to be the period of the greatest structural and functional changes in their ontogenesis.During this period the greatest rate of development is peculiar for body mass and height (11—12 years — mass 16%,length 6%; 14—15 years — mass 25%, length 6%), whereas development of work capacity occurs evenly. Along withrelative stabilization of the rate of body mass and height development beginning from the age of 16 high rate of workcapacity development is observed.Keywords: Greco-Roman wrestling, somatic development, performance abilities.

scholarly journals Quantifying the impact of heat on human physical work capacity; part II: the observed interaction of air velocity with temperature, humidity, sweat rate, and clothing is not captured by most heat stress indices

2021 ◽  
Author(s):  
Josh Foster ◽  
James W. Smallcombe ◽  
Simon Hodder ◽  
Ollie Jay ◽  
Andreas D. Flouris ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Empirical Study ◽  
Air Temperature ◽  
Physical Work ◽  
Climate Index ◽  
Physical Work Capacity ◽  
Air Movement ◽  
Wide Range ◽  
Temperature And Humidity ◽  
The Impact

Abstract Increasing air movement can alleviate or exacerbate occupational heat strain, but the impact is not well defined across a wide range of hot environments, with different clothing levels. Therefore, we combined a large empirical study with a physical model of human heat transfer to determine the climates where increased air movement (with electric fans) provides effective body cooling. The model allowed us to generate practical advice using a high-resolution matrix of temperature and humidity. The empirical study involved a total of 300 1-h work trials in a variety of environments (35, 40, 45, and 50 °C, with 20 up to 80% relative humidity) with and without simulated wind (3.5 vs 0.2 m∙s−1), and wearing either minimal clothing or a full body work coverall. Our data provides compelling evidence that the impact of fans is strongly determined by air temperature and humidity. When air temperature is ≥ 35 °C, fans are ineffective and potentially harmful when relative humidity is below 50%. Our simulated data also show the climates where high wind/fans are beneficial or harmful, considering heat acclimation, age, and wind speed. Using unified weather indices, the impact of air movement is well captured by the universal thermal climate index, but not by wet-bulb globe temperature and aspirated wet-bulb temperature. Overall, the data from this study can inform new guidance for major public and occupational health agencies, potentially maintaining health and productivity in a warming climate.

Relationship Between Physical Activity and the Objective Indicators of Physical Capital for Women in Fitness

2015 ◽  
Vol 6 (2) ◽  
pp. 21-35
Author(s):  
Aleksandra Čuprika ◽  
Andra Fernāte ◽  
Leonīds Čupriks
Keyword(s):  
Physical Activity ◽  
Body Composition ◽  
Physical Fitness ◽  
Functional State ◽  
Physical Capital ◽  
Work Capacity ◽  
Physical Work ◽  
Physical Work Capacity ◽  
The Impact ◽  
Objective Indicators

Abstract As it is mentioned in the action direction Healthy and Workable Individual of the National Development Plan of Latvia 2012 –2020: 30% of all the dead in Latvia have lost their life at the age of being able to work. The main causes of death rate are different diseases (cardio-vascular a.o.), as well as outer death causes (injuries) (Pudule et al, 2012; Štale et al, 2013). Only 8% of the EU and 6% of the Latvian population regularly perform moderate and very difficult physical activity (PA) (Eurobarometer, 2013). Therefore it is necessary to implement purposeful and effective health promoting and risk limiting events to develop the physical capital of one. The understanding of the impact of physical activity on one’s physical capital is not well explored in the previous studies (Hutson, 2012; Maguire, 2008; Goldenberg, 2003; Hedblom, 2009). Therefore, the aim of the study is to determine the relationship between PA and the objective indicators of physical capital for women in fitness. In the study voluntarily participated 33 women (30±4.1 years) from 2 fitness clubs in Riga. In order to determine the respondents’ objective indicators of physical capital were applied: bioimpedance method (TANITA SC330, Japan, 89/336/EC), heart rate variability analysis data processing software ‘Omega’, complex load test with expiratory gas analysis (VIASYS Healthcare GMBH, Germany) and Eirofit tests for adults. In order to determine the level of PA the IPAQ (Craig et al, 2003) short version in Latvian (Kaupuzs & Larins, 2010) was used. Descriptive and inferential statistics were made (SPSS ver.18.0). Several moderately close (0.5<|rs|<0.69; p<0.01) and close correlations (0.7<|rs|<0.99; p<0.01) are determined between the level of PA and indicators of body composition, physical work capacity, physical fitness and functional state of the body. The level of PA has a positive impact on the objective indicators of physical capital. The more physically active the respondent is, the better physical fitness, higher work capacity, better the indicators of his body composition are and better functional state.

scholarly journals Transmission of solar radiation through clouds on melting glaciers: a comparison of parameterizations and their impact on melt modelling

2011 ◽  
Vol 57 (202) ◽  
pp. 367-381 ◽  
Author(s):  
Francesca Pellicciotti ◽  
Thomas Raschle ◽  
Thomas Huerlimann ◽  
Marco Carenzo ◽  
Paolo Burlando
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Radiative Forcing ◽  
Model Performance ◽  
Horizontal Resolution ◽  
Swiss Alps ◽  
Cloud Radiative Forcing ◽  
Correct Definition ◽  
Diurnal Range ◽  
The Impact

AbstractWe explore the robustness and transferability of parameterizations of cloud radiative forcing used in glacier melt models at two sites in the Swiss Alps. We also look at the rationale behind some of the most commonly used approaches, and explore the relationship between cloud transmittance and several standard meteorological variables. The 2 m air-temperature diurnal range is the best predictor of variations in cloud transmittance. However, linear and exponential parameterizations can only explain 30–50% of the observed variance in computed cloud transmittance factors. We examine the impact of modelled cloud transmittance factors on both solar radiation and ablation rates computed with an enhanced temperature-index model. The melt model performance decreases when modelled radiation is used, the reduction being due to an underestimation of incoming solar radiation on clear-sky days. The model works well under overcast conditions. We also seek alternatives to the use of in situ ground data. However, outputs from an atmospheric model (2.2 km horizontal resolution) do not seem to provide an alternative to the parameterizations of cloud radiative forcing based on observations of air temperature at glacier automatic weather stations. Conversely, the correct definition of overcast conditions is important.

Physical work capacity (VO2 max) and work ability (WAI) of active employees (men and women) in Poland

2005 ◽  
Vol 1280 ◽  
pp. 156-160 ◽  
Author(s):  
J. Bugajska ◽  
T. Makowiec-Dąbrowska ◽  
A. Jegier ◽  
A. Marszałek
Keyword(s):  
Work Ability ◽  
Work Capacity ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Vo2 Max ◽  
Men And Women

Physiological responses to maximal effort wheelchair and arm crank ergometry

1980 ◽  
Vol 48 (6) ◽  
pp. 1060-1064 ◽  
Author(s):  
R. M. Glaser ◽  
M. N. Sawka ◽  
M. F. Brune ◽  
S. W. Wilde
Keyword(s):  
Pulmonary Ventilation ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Correlation Coefficients ◽  
Work Capacity ◽  
Peak Oxygen Uptake ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Maximal Heart Rate ◽  
Peak Vo2

The purpose of this investigation was to compare physical work capacity (PWC), peak oxygen uptake (peak VO2), maximal pulmonary ventilation (VEmax), maximal heart rate (HRmax), and maximal blood lactate concentration (LAmax) for wheelchair ergometer (WERG) and arm crank ergometer (ACE) exercise. For this, wheelchair-dependent (n = 6) and able-bodied (n = 10) subjects completed a progressive intensity, discontinuous test for each mode of exercise. Each test was terminated by physical exhaustion and/or an inability to maintain a flywheel velocity of 180 m.min-1. Relatively high correlation coefficients were found between values obtained during the two modes of ergometry for PWC, peak VO2, VEmax, and HRmax. WERG exercise was found to elicit a significantly (P less than 0.05) lower PWC (by 36%), HRmax (by 7%), and LAmax (by 26%) than ACE exercise. Peak VO2 and VEmax, however, were similar for both exercise modes. These data suggest that either exercise mode may be used for fitness testing and training of people who cannot use their legs and that arm cranking may be a superior method to propel wheelchairs.

Lifting Physical Work Capacity as a Function of Frequency

1987 ◽  
Vol 31 (12) ◽  
pp. 1331-1335
Author(s):  
Jeffrey E. Fernandez ◽  
Robert J. Marley ◽  
Nancy B. Stubbs
Keyword(s):  
Laboratory Experiment ◽  
Work Capacity ◽  
Task Design ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Frequency Range ◽  
Lifting Technique ◽  
Male Subjects

A laboratory experiment using 15 male subjects was conducted to document lifting physical work capacity over the frequency range of 2 to 12 lifts per minute and to compare these values to bicycling physical work capacity. Results indicate that bicycling PWC is significantly higher than lifting PWC at the 0.05 level. A variation in lifting PWC as a function of frequency was observed. This could be attributed to lifting technique. Task design should, therefore, not only consider lifting PWC but also the frequency of lift.

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