Explosiveness is trained by combining heavy strength work with fast, intent-driven movement. Use jumps, throws, sprints, and light-load ballistic lifts performed with full effort and full recovery, so that every repetition is fast rather than fatigued.
Power is force multiplied by velocity. Heavy strength training raises the force you can produce; explosive work trains you to produce it quickly. Neglect either half and progress stalls. A strong athlete who never moves fast stays slow, and a fast athlete with no strength base has little to accelerate.
With light and moderate loads, the instruction to move as fast as possible changes the adaptation, even when the bar speed itself is not extreme. Going through the motions at 50 percent of your maximum produces almost nothing. Every rep of explosive work should be performed as though it were being measured.
Keep sets short, three to six reps at most, and rest two to four minutes between them. Place explosive work at the start of the session. The moment quality falls, the set is over. This is the opposite of how conditioning is programmed, and mixing the two logics is the most common mistake.
Two sessions that begin with 10 to 15 minutes of jumps or throws, followed by heavy strength work, plus one sprint or bounding session if your sport requires it. That covers force, velocity, and the reactive quality in between.
Improvements in the first weeks are largely neural and can appear quickly, then slow. Track a simple measure such as a standing broad jump every four weeks. Detail is in Power Development and Explosive Strength.