Small Pecs? You Don't Train Explosively
To maximize muscle building, the nervous system needs to fire at full speed to maximize fast-twitch muscle fiber recruitment. Adding an explosive component to your training improves muscle fiber recruitment for the rest of your workout. The more muscle fibers we stimulate in training, the greater the growth potential from a workout.
Explosive training works best after your dynamic warm-up and before your main lifts. You'll prime the nervous system and maximize muscle fiber recruitment. Focus on generating as much power as possible on each rep. Pick one of the following for 3 sets of 5-8 reps before your main lifts on upper body training days.
Incline Plyo Push-Up
Medicine Ball Pop-Up
You can also use Post Activation Potentiation (PAP), which is a physiological adaptation that describes the immediate enhancement of force during explosive movements after a heavy lift.
In plain English, you'd do a relatively heavy strength training exercise then follow it with an explosive exercise. That explosive exercise should be similar to the strength exercise. For chest training, you might do a bench press variation and then an explosive body weight exercise like one of the above.
Example: Do 5 sets of 4 on the bench press. Each set would be immediately followed by a set of 4 explosive push-ups. Rest 60 seconds between the push-ups and the bench presses.