Final answer:
Complex training is used to improve both strength and power by combining heavy resistance exercises with explosive power movements for the same muscle group, such as squats followed by box jumps.
Step-by-step explanation:
The training system used to improve both strength and power simultaneously is known as complex training. This method involves pairing heavy resistance exercises, which are aimed at building strength, with explosive power movements that target the same muscle groups. An example of this would be performing a set of heavy squats followed by a set of box jumps. The combination of these two types of exercises is believed to enhance neuromuscular performance and increase both strength and power concurrently.
Complex training differs from other workout methods in that it specifically integrates strength and power exercises within the same workout. In contrast, pyramid training progressively increases or decreases the weight and/or repetitions over successive sets, circuit training involves cycling through a series of exercises with minimal rest, and superset training involves performing two exercises back to back with no rest in between, but not necessarily with the focus on strength followed by power.