Power Is King, When it Comes to Knock Outs
Power is defined as force produced over a distance per unit of time. Within boxing this is usually a result of a total body, chain link summation of coordination movements (Cordes, 1991). So in boxing, the power is generated starting from the stance, rising up from force generated by pushing the feet into the ground, then travels through the knees, hips and trunk twist, to the shoulders, down the arm into the fist. By introducing power training, athletes will increase the rate of force development, thus the amount of power behind each punch.
Where people go wrong.
Heavy resistance training with slow velocity of movement primarily improves maximal strength, not power. So being able to lift 200lbs on your squat does not necessarily make you powerful. Power training is lifting light to moderate loads at high velocity (30 to 60% of 1 rep max), therefore increasing force output at higher velocities and rate of force development (NSCA, 2010).
For example, lower body exercise could be a weighted squat jump, while the upper body exercise could be ballistic bench press throw.
The graph shows the function of time, indicating maximal strength, rate of force development (RFD) and force at 0.2 seconds. The blue line represents untrained subjects, dashed purple line represents heavy resisted trained subjects while the dashed black line shows the explosive trained subjects.
When functional movements are performed such as a back hand straight in boxing, force is typically applied very briefly, often less than 0.1 to 0.2 seconds, where as absolute maximal force development may take up to 0.8 seconds (NSCA, 2010).
As you can see, at 0.2 seconds an explosive trained athlete can generate significantly more force than a heavily trained or untrained athlete. Therefore an athlete who trains using explosive ballistic exercises will have a physical advantage over their opponent, increasing their ability to generate force quickly, improve reactive power and enhance power endurance.
Think of this in a boxing scenario, an heavy resistance trained boxer can generate more force but takes longer to throw the punch (say 0.8 seconds). Whereas a explosively trained boxer can generate more power quickly (0.2 seconds), but less overall force. This means the explosive boxer can connect with his power shots before the heavily trained boxers punchers land (first to the punch).