[Physical workload and maximum acceptable work time among supermarket workers in Cali, Colombia]

In order to guarantee safety and health conditions in labor the maximum physical workload that can be supported by a worker during a labor day, without causing fatigue, must be determined. The objective of this study was to determine the relationship between the physical load, expressed as relative heart rate (RHR), and the maximum acceptable work time (MAWT) in a Colombian working population (n = 30) from a tropical environment.

An observational study was carried out during a typical labor day in the warehouses of a supermarket. Physiological, demographic, health and labor conditions data were collected. The resting heart rate level and the average heart rate during work were measured, and the RHR was estimated according to with the model described by Wu & Wang.

Significant correlations between MAWT and RHR and other physiological variables were observed. 43% of workers didn't fulfill the MAWT. The only single variable that was associated with fulfillment was a body mass index under 18.5 Kg/m2; the other associated variables were some specific conditions of the occupational environment. Results showed a negative correlation between physiological variables and MAWT. The RHR showed its potential usefulness in the enterprise's occupational health practice.

It is important for companies to diminish extended schedules and implement physical conditioning programs.