Complex training is designed to improve your explosive power . Complex training should not be tried by beginners or those with inadequate body strength. It is a high-risk, high-reward type of athletic training .
It doesn't help you to continually get stronger if power development is not there also. Power, or speed strength (how fast your muscles can produce force) is one of the best physical predictors of success in sports. Plyometric exercises help you to increase power.
Traditional barbell and dumbbell strength exercises do not allow you to move at the speeds necessary to improve power. Strength training gives you the muscular and nervous system development needed to develop optimal power.
Complex training supersets a strength exercise with a biomechanically similar power exercise. An example would be barbell squats and repeating full-speed squat jumps. The squat jumps would be performed immediately following the barbell squats to get maximum neuromuscular adaptations.
You would do a set of squats at 85% of 1 Rep Maximum (5 reps) followed immediately by a set of full-speed repeating squat jumps (8-10 reps). This is an advanced training method and should not be performed by athletes who do not have adequate stabilization strength and muscular strength.
Other plyometric exercises can also be superset this way. It is also advisable to choose exercises that mimic the movements in your sport (transfer-of-training-effect).
Complex training is designed to increase speed strength and create neuromuscular adaptations throughout the full range of motion.