The impact of low hemoglobin levels on the work performance of 74 rural Nepali villagers was examined with a 3 minute exercise step test. Work output was standardized at 75 watts for men and 55 watts for women. Hemoglobin values ranged from 4.2-15.7 g/dl, and averaged 12.0 ± 2.7 g/dl for 35 men and 10.9 ± 1.72 g/dl for 39 women. Low hemoglobin levels significantly elevated the heart rates and recovery times of the men, but not of the women. A positive relationship with oxygen uptake and a negative one with net mechanical efficiency was found for men but not for women (anemic men appeared more efficient as they used up marginally less oxygen during exercise). Values are in good agreement with those recently published for Gurkha soldiers, but are at variance with those examining the step test performance of Nepali women. In the light of behavioral data on work patterns, mild anemia may have little impact on the performance of moderate self-paced physical activity. Nepali villagers pause frequently during the course of subsistence activities, a behavior which allows time for recovery from an elevated pulse rate. © 1992 Wiley-Liss, Inc.

Minute-by-minute heart-rate recordings over a period of 24 hours were obtained once for each of a group of 29 elderly women, 14 of whom lived in private accommodation, and 15 of whom lived in institutionalized homes for the aged. Activity diaries were kept on the subjects during the measurement period. A comparison of individual 24-hour profiles, diaries, and group averages was made. Strong positive correlations were found in both groups between average waking and sleeping heart-rates, and between the standard deviations of the two periods. A marked predominance of sedentary activities among the institutionalized women was found to correspond with lower waking heart-rates, and flatter 24-hour profiles. However, these characteristics could also be explained as an age effect. Cosinor analysis indicates that, for the majority of these subjects, a curve made up of a combination of two periodic components with maxima around midday and 8 pm affords a reasonable representation of diurnal variation.