To examine the effects of strength training with superimposed vibrations ten subjects trained over a period of six weeks (three sessions per week) one leg with back squats and superimposed vibrations and the other leg with traditional squats. In each training session participants performed 4 sets with 8-12 repetitions. Before and after the training period maximum strength and rate of force development were measured. The results show that both training modes induced comparable and statistical significant increases in maximum strength (vibration training +6.5%, traditional training +6.2%. The slight increases in rate of force development in both groups didn't reach statistical significance. As a consequence it seems that strength training with superimposed vibrations for the leg extensor chain is not superior to a traditional training mode.