Complex training, also known as contrast training or post-activation potentiation training, involves the integration of strength training and plyometrics in a training system designed to improve explosive power. According to Jace Derwin: Complex training relies upon the performance of a strength exercise, often resistance based, followed by a plyometric exercise. The strength and the plyometric exercise are usually biomechanically similar i.e. they move through similar ranges of movement. For example, a back squat followed by a box jump; or a bench press exercise followed by a jumping clap push up. Such a combination is referred to as a pair or a contrast pair. The resistance based exercise will often be a near maximal effort—about 75–90% of the athlete's maximal lift. The plyometric portion of the training should be completed in an explosive manner. Sets are often used. Between the performance of the strength exercise and the plyometric exercise there is between a 3–12 minute rest period; opinions vary on the most efficient length. As the muscles have been intensely activated by the strength exercise, this develops in the muscles a greater potential to apply force than they would have normally. This added potential to apply force is called post-activation potentiation (PAP). It is the fundamental basis of complex training. This potential to apply force, generated by the strength exercise, is utilised by the athlete in the plyometric exercise to boost their power output to a level greater than it otherwise would have been had they been doing plyometrics alone. In this way, the plyometric exercise can be performed more powerfully. For instance, an athlete may jump higher after they have completed a back squat at 90% maximal lift, had a rest for 3–12 minutes, and then jumped; as opposed to only jumping, where they would not get this improvement. The length of the rest period is chosen to be long enough to allow the athlete to recover after the strength exercise, whilst also being short enough to allow for the high degree of muscle activation to be utilised in the plyometric exercise. Rate of force By integrating plyometrics with strength training, there is an added benefit of improving rate of force, the speed with which force is achieved in movement. Long term effects of complex training The ambition in a complex training regime is not just to achieve better results in an individual workout but also to condition the athlete