Open AccessAssessments by HR and %HRR of Occupational Work Exertion for Alternating Periods of Rest and Manual Labor
Author(s) -
Eguchi Yasumasa,
Kawanami Shoko,
Horie Seichi,
Yamato Hiroshi
Publication year - 2011
Publication title -
journal of occupational health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 59
ISSN - 1348-9585
DOI - 10.1539/joh.11-0048-oa
Subject(s) - exertion , perceived exertion , anaerobic exercise , heart rate , metabolic equivalent , work (physics) , rest (music) , physical therapy , medicine , cardiology , physical activity , blood pressure , engineering , mechanical engineering
Assessments by HR and %HRR of Occupational Work Exertion for Alternating Periods of Rest and Manual Labor: Yasumasa Eguchi, et al. Department of Health Development, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan—Objectives Metabolic equivalents (METs) and relative metabolic rate (RMR) as calculated by oxygen uptake ( V ˙ O 2 ) are often used to assess physical exertion. In practice, accurate measurements of V ˙ O 2 are dificult; heart rate (HR) values represent an alternate index of physical exertion. We investigated whether one can assess physical exertion based on HR in the workplace, even if the physical task in question involves alternating periods of strenuous anaerobic activity and rest. We also examined the potential usefulness of assessments based on percentage of heart rate reserve (%HRR) and percentage of oxygen uptake reserve (% V ˙ O 2 R ). Methods Six healthy men were asked to perform several physical movements. HR and V ˙ O 2 were recorded in real time. Results HR and V ˙ O 2 are significantly correlated even under conditions of various repeated intermittent movements including anaerobic exertion. Cumulative fatigue results in inadequate recovery in various parameters indicating suficient rest times, whereas V ˙ O 2 values recover immediately. One movement may generate large differences in HR among individuals, but not in V ˙ O 2 . We found no significant differences between dispersion for %HRR and V ˙ O 2 R . However, as with HR, %HRR values indicated insuficient recovery after strenuous exertion. ConclusionsV ˙ O 2 alone does not adequately reflect the exertion entailed by certain physical activities. HR is more useful than V ˙ O 2 in evaluating the exertion required by physical labor in individual workers. While we can use %HRR and % V ˙ O 2 R to compare physical exertion from individual to individual, %HRR is more valuable, since % V ˙ O 2 R can underestimate physical exertion in recovery periods for the same reasons as V ˙ O 2 .