Or to make it even simpler:
Squats followed by jump squats. Bench presses followed by explosive push-ups. Pull-ups followed by medicine-ball slams.
The concept isn't new — researchers have been studying it since the 1960s, and strength coaches and athletes have been employing it for at least that long — but I never run out of new applications for it. I use it at various times, and with various modifications, with all my athletes, as well as the regular folks I train.
With athletes, contrast training builds strength and power simultaneously. For non-athletes, it's a great way to tap into high-threshold motor units for hypertrophy, or to boost the metabolism to improve body composition. And while you're accomplishing those objectives, you're also changing up your workout in a way that's fun and challenging."