Strength Symmetry and Imprecise Sense of Effort in Knee Extension

To verify the asymmetry in strength and the sense of effort between the preferred and non-preferred leg as well as differences between perceived and real workload achieved during trials for a maximal one-repetition knee extension, 32 subjects, all physically active (24 males and 8 females) performed one-repetition tests for knee extension (1 RM) with their preferred and non-preferred leg. The subjects reported the sense of effort by means of the Borg’s scale for subjective perceived effort. Asymmetry was quantified for the workload and the sense of effort. We found similar strength and sense of effort for both legs. There were differences between the perceived and real workload when normalized by the maximal effort, mostly for higher intensities. Similar strength could be achieved between the preferred and non-preferred leg; however, the subjects’ perception about the workload can be imprecise, which may lead to mistakes when controlling training overload by means of the sense of effort.