Work performance of Chinese cycle haulers: Controlled field experiments in normal work conditions

Abstract

Forty-five male Chinese cycle haulers performed a controlled field experiment under mild winter conditions. The objective was to gain insight into factors that affect work performance. Each man hauled the same 481-kg load around a Beijing street course of 14.18 km. The experiment was a measured sample of the same work they do routinely, on the same roads, using similar human powered hauling cycles (modified only enough to carry observers and instruments). The course was completed at a mean speed of 10.4 kph and mean time of 84.2 min. While there was considerable variation in individual pace and in pace change during work, the haulers performed at relatively high output in reference to their capacities. Mean heart rate was 156.8 +/- 16.1 bpm, 83.9% of maximum. The men had average body build and were average in size for the general Chinese population (X stature = 169.7 cm) although they showed relatively high aerobic capacity (determined in laboratory tests). Performance levels during experiments appear to match habitual work patterns, and self-pacing emerged as a major behavioral finding of this research. Speed, a primary index of job performance, showed significant correlation to heart rate, VO2max, variation in windchill, self-reported health and other variables, with a multiple regression coefficient of 0.811. Similar patterns were seen for heart rate relative to speed, except that physical size, education, and other behavioral variables were also predictors.

The China Productivity Project: Results and conclusions

“…Field test data on speed, heart rate variation during the test, and heart rate as a percentage of maximum all have a voluntary dimension. This is the case because the haulers were instructed to complete the field course at their own chosen pace, and our observations indicate that they did set what was apparently their habitual pace (see Steegmann et al, 1995b). There was nothing to gain from higher speed nor to lose from slower performance.…”

“…The two observers, riding as part of the load, also noted work behavior. More detail is given in Steegmann et al (1995b).…”

“…The mean heart rate/min during the 14.18 km outdoor experiment divided by the mean speed during the experiment; assumption that the lower the heart rate at any speed, the higher the work capacity; Polar Vantage XL recording heart rate monitor (a chest strap sensor-transmitter and a wrist receiver-recorder system) was used (Steegmann et al, 1995b) Anthropometrics Include height, sitting height, and lower leg length (anthropometer), weight (beam balance), elbow breadth (sliding caliper) and skinfolds (Lange calipers) and employed standard techniques (Lohman et al, 1988); BMI 5 wt kg/ht m 2 ; relative sitting height 5 sitting height/height; relative lower leg length 5 lower leg length/height 2 sitting height; fat-free mass, see Lohman (1981); calf muscle area, cm 2 , see Frisancho (1990); for calf muscle area, maximum calf circumference determined by insertion tape, and a medial, vertical skinfold was taken using Lange calipers at the same level as the maximum circumference Age Calculated in decimal years as the interview date minus the birth date Health Ratings of haulers, on five-point scales, were assigned by a Chinese physician after a health interview and physical examination; the hauler also rated his own health on a five point scale; his rating of the health of each household member was summed and averaged for the household health score Days ill…”

Porters of the eastern hills of Nepal: Body size and load weight

“…Although Steegman et al (1995Steegman et al ( , 1997 found that speed correlated positively with aerobic capacity (V O 2max ) and thereby indirectly with physical size in Chinese haulers, neither physical size nor physiological factors were important predictors of productivity as measured by daily or monthly pay of the haulers. This observation led the authors to conclude that ''the management of work pacing, controlled largely by the individual haulers, compensated for lack of physical capacity'' (Steegman et al, 1997, p. 311).…”

Postmenopausal function in context: Biocultural observations on Amish, neighboring non‐Amish, and Ifugao household health

“…The interview format was based on methods developed for productivity research in Beijing, China (Hewner and Sun, 1995;Steegmann et al, 1995. Details of the interview protocol are reported in Hewner (1993).…”