RELATIONSHIPS BETWEEN STRETCH-SHORTENING CYCLE PERFORMANCE AND MAXIMUM MUSCLE STRENGTH

This study aimed to examine the relationships between muscle power output using the stretch-shortening cycle (SSC) and maximum strength, as measured by the 1 RM (1 repetition maxi-mum) test and the isokinetic dynamometer under elbow flexion. Sixteen trained, young adult males pulled a constant load of 40 % MVC (maximum voluntary elbow flexion contraction) by bal-listic elbow flexion under the following two preliminary con-ditions: 1) the static relaxed muscle state (SR condition) and 2) using the SSC (SSC condition). Muscle power was deter-mined from the product of the pulling velocity and load mass by a power measurement instrument with a rotary encoder. The 1 RM bench press (1RM BP) and isokinetic maximum strength under elbow flexion with the Cybex-325 were measured as indi-cators of dynamic maximum strength. 1) The early power output exerted under the SSC condition showed a significant and high correlation with the 1 RM BP (r = 0.83), but only moderate correlation with the isokinetic muscle strength (r = 0.50–0.67). 2) The contribution of the 1 RM BP to the early muscle con-traction velocity exerted under the SSC condition was large. These results suggested that muscle power exerted using the SSC shows a stronger relationship with maximum muscle strength measured by a 1 RM test rather than isokinetic maxi-mum strength. KEY WORDS muscle power, elbow flexion, 1 RM bench press, isokinetic strength, counter-movemen