Pro Boxing Training: Physics behind a power punch

Types of power punches

Many times people use common words to describe punching power in boxing: Things like "explosive", "heavy hands", "sharp" and so on. All those can be explained by physics. There are actually two kinds of striking power.

1. The Sharp Punch

Force is Mass times Acceleration (F=ma). Force is measured in "Newton" units. You can test and put values on different objects. For example, this is how much force something can take before it breaks, as in the case of boards or bones. This is shattering, explosive power, to speak figuratively. It causes pain and brings incapacitation through tissue irritation damage. This is the typically the fast hand speed type of impact. Like a whip, it strikes out and lashes quickly. Max force can last only one-millionth of a second, for example, and it is the peak of the curve which brings out to the next aspect...

2. The Heavy Punch

Impulse is Force times Time (J=Ft). The unit for both Impulse and Momentum is "Newton Second" Force in real life. Its curve is especially related to punch: it flows and at the peak of the curve is the "Force". It's the total amount of force that flows, not just the tiny, instantaneous fraction of a second (the surface area under the integral curve). In essence, the more impulse the punch produces, the more and the faster the object will be moved. Impulse causes a change of momentum. Momentum is Mass times Velocity (p=mv). The more momentum, the faster and farther the object will be moved. If connecting with the head, it has the potential to bring about a knockout because the brain shifts inside the skull when the head moves. It unbalances the object or opponent because of the movement incurred. This type of strike can also be called a "push" strike, although it is not literally a push. Literal push has a flat line on the force curve, but a punch that pushes back a torso or a head moves like a wave. A heavy punch is like being hit by a telephone pole: it does not flex, instead, transmitting a huge wave of force. Stiff and slow perhaps, but packing a wallop.

1+2 = Which is better?

It's like jumping: someone might jump the longest distance but someone else will jump higher. Neither is the best for different reasons.

Sharp punches will cut, break bones and tear tissue: they're faster and will wear and tear, but not so much cause an immediate knockout.

Heavy punches will potentially be one punch KO's, but they are slower because of the biomechanics requiring one to focus their bodyweight firmly as an anchor, grounded to transmit maximum impulse without unnecessary flexing. Even if blocked, the target will move and be thrown off balance.

It's a tie, depending on the puncher. Not the physical art itself but the artist, all do it differently but with a common goal: to win the fight.

Spotting the different punch types

When seeing boxers hitting heavy bag or mitts, there are certain things to keep an eye on and sounds to keep your ears perked at.

A sharp punch is like whip, a cracking type of sound, A heavy punch is like a loud thud.

Different punch techniques naturally have different effects. Straight techniques like the cross punch are based more on bodyweight transfer than the hook, for example, which is more of a rotational technique rooted on peak velocity at the moment of impact. The uppercut has its own special niche due to gravity, whereas hooks and straight punches can cause the target to be knocked back or to the side lessening the impact the head takes. With uppercuts to the chin, the whole momentum of the attack are absorbed due to gravity pulling you down while the punch arches upward, being sandwiched between two opposing forces.

The ”sweet science” is truly full of measurements and units. Enjoy the sport and the physics involved!