Participants
The participants were 50 women aged 32 (SD 7) years and 58 men aged 31
(SD 7) years. Their jobs mainly included materials handling, construction,
and metal industrial tasks (Table 1). The materials handling tasks performed
by 18 female cleaners of aircrafts and 16 male handlers of luggage were
studied at the Bangkok airport. The construction tasks were done by 10
male carpenters, 2 female brick layers, 4 male brick layers, 18 female and
4 male material providers, and 2 male pile drivers. The metal industrial
tasks included steel bar production, which was done by 12 female workers,
and steel wiring performed by 21 male workers.
The results of a medical screening supplemented by a submaximal
cycle-ergometer test, indicated that all participants were healthy. In the
aforementioned occupational categories the estimated mean maximal oxygen
consumption related to body weight varied from 35.3 to 45.4 ml/min/kg in
men and 20.1 to 28.0 ml/min/kg in women (Table 1). The participants were
informed about the study methods and protocol.