The purpose of that study was to determine the effect of training of one side of the body on changing the value of the muscle torques on trained and untrained sides. Twenty female students from the Warsaw University of Physical Education were subject to a four-week knee joint power training regimen on the specially designed stand. The same load but different rest time between lapses (120 vs. 30 seconds) were applied to both groups. The load was applied in a form of bending moment equal to 30% of MVC. Bilateral knee force was measured on the Biodex System 3 Pro under isometric conditions. Extension of the rest time between lapses resulted in a higher increase of the strength build-up. Power training causes a similar increase of force generating capacity in both groups for untrained leg. Therefore we have to conclude that there is no influence on homogeneous force improvement for untrained leg after power training.