3. Simplified whole body fatigue typically occurs “at the end of an 8 our
shift” where work is “greater than thirty to forty percent of maximum
anaerobic activity” (Wickens, Liu, and Becker, 2004).
To determine thirty percent of max aerobic activity, an evaluation of
the work activity must be determined.
According to Wickens, Liu, and Becker, high athletic activities are
designated a 10. Let’s put this in perspective.
Heavy work uses 5.0 and 7.5 per Kcal/min. Very heavy work uses 7.5
and 10.0 Kcal/minute. Extremely heavy work uses plus 10.0
Kcal/min.
Even fit workers are not able to maintain a steady state at 10.0 Kcal per
minute for 8 hours.
Healthy males cannot work continuously over 5 Kcal/min., females
3.5 Kcal/min.
Heat in the environment or polluted environments greatly effects the
Kcal/minute
4. What happens when the body cannot hold
steady state?
Not enough oxygen is produced to meet all the energy needs and total
body fatigue can result.
Now
For true determination of Kcal per minute specific individuals and
environments can be tested using a Douglas bag for expended oxygen
levels , as well as some monitoring devises (can be monitored
remotely).
Keep in mind…this information is not al inclusive and very simplified
and only takes into account totally healthy people.
Also……Heat environments greatly effect the numbers.
5. Wickesn, C.D., Liu, J.L., & Becker, S/G.(2004). Work physiology. Human
Factors Engineering. Upper Saddle River, New Jersey. Pearson
Education, Inc.
See future power points on
Situational awareness
Cognitive decision making
Stress and workload
