Premixes are pre-programmed versions of the workout that take pieces from one or two workouts and combine them in different ways, making a longer, shorter or just different workout.
It's as if you programmed a workout into your DVD player by choosing various chapters that you want to play in a specific order.
For example, on the KPC/L&G DVD, there are several premixes combiniing segments of KPC in different ways, several using different formats from L&G chapters, and several that combine the two workouts in different ways.
The earlier DVD's didn't have premixes, but the workouts from Inensity Series on do.
Of the workouts you have on video, GS and IS have premixes (PH and S&H do not). In IS, for example, the PUB/PLB DVD has 'up-only' and "down-only' premixes for both upper body and lower body, and a 'bonus workout' (premix) that combines upper and lower body in an hour-long workout.
