The purpose of this study was to observe the effects of a submaximal isometric training program on estimation capacity at 25, 50, and 75% of maximal contraction in isometric action and at two angular velocities. The second purpose was to study the variability of isometric action. To achieve these purposes, participants carried out an isokinetic extension movement of the dominant lower limb during six test sessions and nine training sessions. Following the training program, estimation capacity in the different actions did not improve. However, an improvement in performance was observed with a reduction in the variability of submaximal isometric actions. The proprioceptors activated in isometric action seemed to adapt to the training program itself, which would promote better adaptation by a greater solicitation of internal feedback. (Contains 2 figures and 2 tables.)