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.

Physiological effects of hydrogen sulfide inhalation during exercise in healthy men

1991 ◽  
Vol 71 (5) ◽  
pp. 1872-1877 ◽  
Author(s):  
Y. Bhambhani ◽  
M. Singh
Keyword(s):  
Hydrogen Sulfide ◽  
Oxygen Uptake ◽  
Maximal Exercise ◽  
Lactate Concentration ◽  
Young Male ◽  
Work Capacity ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Maximal Power Output ◽  
Male Subjects

Occupational exposure to hydrogen sulfide (H2S) is prevalent in a variety of industries. H2S when inhaled 1) is oxidized into a sulfate or a thiosulfate by oxygen bound to hemoglobin and 2) suppresses aerobic metabolism by inhibiting cytochrome oxidase (c and aa3) activity in the electron transport chain. The purpose of this study was to examine the acute effects of oral inhalation of H2S on the physiological responses during graded cycle exercise performed to exhaustion in healthy male subjects. Sixteen volunteers were randomly exposed to 0 (control), 0.5, 2.0, and 5.0 ppm H2S on four separate occasions. Compared with the control values, the results indicated that the heart rate and expired ventilation were unaffected as a result of the H2S exposures during submaximal and maximal exercise. The oxygen uptake had a tendency to increase, whereas carbon dioxide output had a tendency to decrease as a result of the H2S exposures, but only the 5.0 ppm exposure resulted in a significantly higher maximum oxygen uptake. Blood lactate concentrations increased significantly during submaximal and maximal exercise as a result of the 5.0 ppm exposure. Despite these large increases in lactate concentration, the maximal power output of the subjects was not significantly altered as a result of the 5.0 ppm H2S exposure. It was concluded that healthy young male subjects could safely exercise at their maximum metabolic rates while breathing 5.0 ppm H2S without experiencing a significant reduction in their maximum physical work capacity during short-term incremental exercise.

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.

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.

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