Class 19 Flashcards
(26 cards)
physical work capacity
capacity to generate metabolic energy
purposes of PWC evaluation
compare with physical work demands, identify high risk workers
PWC depends on
the bodys ability to take oxygen from the atmosphere & deliver it to cells for oxidation of food into energy
the body’s molecule of energy
ATP
ATP reaction
ATP -> ADP + P_i + energy
ATP storage
locally in muscles, 2-3 seconsd of energy supply
Metabolism is
the process of regenerating ATP from food
Aerobic metabolism
O2 is required, slow efficient prodfuction of ATP, created CO2 & water
Anaerobic metabolism
O2 not required, fast production, inefficient, creates Co2 water and lactic acid
the psysiological responses to increase in workload
stroke volume increases, cardic volume increases
cardiac volume
heart rate * stroke volume
Aerobic capacity
max capacity to utilize oxygen
AC depends on
the work task
AC units
mL O2 /kg*min
tests for measuring AC
maximum stress test, submaximal stress test
maximum heart rate
220 - age
VO2 max equation depends on
sex, bmi, pfa, par
pfa
perceived functional ability
par
physical activity rating
PWC units
Kcal/min
NIOSH recommendation
33% of AC for 8 hours of work
How to determine PWC or recommended work rate
- flat % of AC 2. Predict based on AC and working time
Energy Expenditure (EE)
metabolic demands of a task
Estimating task demands
- average reported values 2. subjective ratings 3. estimate from heart rate 4. task analysis
