When we do a ''classic'' preparation, we will first develop the strength, then we will raise the power according to this new strength. This is the most common way (and it works). At the same time, in order to save time in busy seasons and to bring lucidity and always different stimuli (hence the interest of modern physical preparation), we will mix the two, i.e. the development of strength with that of speed/power. This is called "Complex Training"...