Effects of psychophysical lifting training on maximal repetitive lifting capacity

The purpose of this investigation was to determine the effectiveness of psychophysical lifting training on maximal repetitive lifting capacity. Maximal repetitive lifting capacity was defined as the maximum box mass that could be lifted for 1 hr to a height of 132 cm at a rate of 6 lifts/min. Eight male subjects participated in five psychophysical lifting training sessions each week for 4 weeks. During each session subjects were presented with one empty and one heavily loaded box and asked to adjust the box mass to the maximum load they felt capable of lifting for 1 hr. This load was lifted at a rate of 6 lifts/min to a height of 132 cm for two 15-min periods each session. Heart rate was recorded, and subjects were asked to provide a rating of their perceived exertion. At the end of 4 weeks of training, subjects did not select a heavier training load, exhibit a decreased training heart rate, or report a decreased rating of perceived exertion. The training program did produce a significant increase in 1-hr maximal repetitive lifting capacity, as indicated by a greater box mass selected, but there was no concomitant change in VO2, heart rate, or rating of perceived exertion. It can be concluded that 4 weeks of psychophysical training of inexperienced lifters can produce a substantial increase in work output for a given energy expenditure. These increases are attributed to neural factors (skill, neuromuscular coordination) and to possible increases in the muscular endurance of specific muscle groups occurring with practice.