Traditionally, static stretching and large muscle dynamic movement prior to certain activities has been used as a warm-up activity and has been reported to enhance performance. The purpose of this study was to investigate the effectiveness of these two popular warm-up activities as a performance enhancement technique. Methods. Twenty-four college age students with no history of orthopedic knee problems volunteered for the study. Each subject performed isokinetic knee flexion and extension with their right leg at 60 and 180 deg/s. All subjects performed pre-performance activities prior to the isokinetic testing. The three trials were separated by at least two days and the order of trials was randomly assigned. The three conditions consisted of no warm-up (NW), passive static stretching warm-up (SW), and dynamic warm-up (DW). NW consisted of 10 minutes of supine resting. SW consisted of two stretches for the quadriceps and two stretches for the hamstrings with each stretch performed four times for 30 s. DW consisted of a 10-minute treadmill walking/jogging protocol at an intensity that was at 60% of their predicted maximum heart rate. The mean differences were determined by ANOVA and a Tukey post hoc test was used to determine where the differences occurred. Results. There were significant differences between the three trials for both knee extension and flexion. The greatest peak torque for knee extension and flexion for both 60 and 180 deg/s occurred with the DW trial. The lowest torque was performed with the SW trial. Discussion. This investigation supports the current literature concerning stretching and its effect on performance parameters. DW increases blood flow and temperature of the working muscles in the lower extremities. This appears to give the muscle added performance benefits while NW and SW appears to provide the least amount of benefit when performing isokinetic knee extension and flexion. Most of the current research focuses on the elastic properties of the stretched muscles. It appears that the muscle continues to remain in an elongated state prior to performance and may decrease the muscles ability to store elastic energy. This causes the muscle to produce less contractile force. Conclusion. DW produced the greatest torque production during knee extension and flexion. SW provided the least benefit when performing isokinetic knee extension and flexion. Clinicians, physical educators, coaches, and athletic participants can use this information when determining the best type of warm-up activity for performance.Keyword(s): athletics/sports, exercise/fitness, performance