How to Punch Harder – Increase Your Punching Power Using Physics

If you are into fighting sports such as boxing, kickboxing, MMA, sanda or even a traditional martial art, you probably want to increase the punching power of your fists. When discussing how to punch harder one can hear contradictory advice for example “speed equals power” and “power is not speed”. It seems much of the advice and exercises suggested for increasing your punching power is not based on proper physics, leading to confusions as the above.

In this article we’ll discuss the physics of punching and show that some of the frequently perpetuated advice is not entirely correct, while also exploring new ground. The article doesn’t really contain much in terms of specific tips, tricks, and exercises for increasing punching power. It will, however, provide you with the right idea and mindset for training so you understand what is required to deliver heavier punches. You can then select whatever exercises work for your training routine. Here is how this article is structured:

  1. What is a hard punch?
  2. The physics of punching hard
  3. Increase your punching power by punching with high velocity
  4. Increase punching power by putting more mass behind the punch
  5. Faster energy release for maximum punching power
  6. How to punch harder

Let’s begin with:

What is a hard punch?

This might sound trivial, but definitions are key so before we answer the question “How to punch harder?” we need to define what “harder” (or “heavier”) actually means. This will allow us to explore the physics and arrive at the correct answer.

There are two aspects by which one can define a punch as “hard”: impact force and effect on the opponent.

Boxer Throwing a Heavy Punch

In terms of effect we could say a punch was relatively hard if it achieved a knockout (KO). In a less extreme definition we could consider a punch to be hard if it broke the opponent’s structure and balance sufficiently to open them up for follow-up punches. However, the effect of a punch depends on:

  • the positioning of both fighters
  • the fighter bodies’ momentary center of balance and vector of movement
  • the fighter bodies’ inertia and the local inertia of the body part where the punch lands
  • the exact point and angle of where the punch lands
  • the hardness / softness of the tissue being impacted

to name a few…

If we define a punch as “hard” judging by its effect, we’ll go nowhere in trying to land harder punches as we’ll basically need to develop an entire fighting system as a response.

However, if we forget about those complications for a moment and focus only on the impact force of the punch then we can use a fairly simple physics model to explain the different factors affecting it. We simply need to use the laws governing the generated force in terms of kinetic energy (energy of a body in movement) and the impact force resulting when that energy hits another object.

The physics of punching hard

One can encounter the following simple equation in multiple sources on punching technique:

Force = mass · acceleration

This comes from Newton’s second law (law of motion) which applies to net force. This leads many to say that speed equals power when it comes to punching harder, probably assuming that one can’t change the other variable – mass. Others say increasing punching power is all about the mass one can put behind the punch, which is sometimes incorrectly equated to the mass of the arm (leading to the wrong belief that muscle build-up leads to increased punching power).

However, the net force is not what we are interested in! Instead, if we want to punch harder, we should be interested in generating greater kinetic energy. A different equation is called for to estimate that energy:

Kinetic Energy = (mass · velocity2) / 2

This formula is derived directly from Newton’s law of motion above.

Why is that important for punching harder? One thing is immediately visible – the velocity has a much greater impact on the kinetic energy as it is squared. Here is a short table showcasing how changing the speed of your punches results in a harder punch even with the same exact mass behind the fist. The calculations in it were performed using our online kinetic energy calculator (1 J = 1 N.m).

MassVelocityKinetic Energy
2 kg4 m/s16 J
2 kg5 m/s25 J
2 kg6 m/s36 J
2 kg7 m/s49 J
2 kg8 m/s64 J

If the relationship was linear, doubling the velocity of our fist from 4 m/s to 8 m/s would have resulted in a doubling of the energy in it, resulting in a two times harder punch. However, due to the quadratic relationship doubling the velocity of the punch quadruples the energy it carries. It goes from 16 J to 64 J which would translate to a 4 times increase in punching power according to the kinetic energy formula.

On the other hand, if we are able to double the mass behind our punch it will result in just a doubling of the power. E.g. increasing the mass from 2kg to 4 kg would result in just 32 J of energy with 4 m/s velocity.

However, even the kinetic energy equation doesn’t tell the whole story on how to punch harder. The appropriate way to judge how hard a punch is by measuring its impact force.

Equation for the Impact Force of a Punch

While the impact force depends directly on the kinetic energy, it also depends on another variable – the time in which the force is released. The release time in itself depends on the distance in which we are able to release the energy during a punch. Here are the two equations describing the relationship between impact force and the mass, velocity on impact, and time or distance of impact:

Impact Force = (mass · velocity2) / (distance · 2)

which is equivalent to the formula:

Impact Force = (mass · velocity) / impact duration

Since this is all measured in a three-dimensional vector space the above equation means that there are four variables we can influence in order to deliver a harder punch:

  • mass behind the punch
  • velocity of the fist on impact
  • speed of energy release
  • punch alignment

The alignment is important since the equation assumes the force is exerted along a vector perpendicular to the punching surface. If the punch is misaligned, its impact will be reduced depending on the discrepancy from a right angle. Below we will assume good alignment and focus on the first three factors in more detail.

Increase your punching power by punching with high velocity

Looking at both the kinetic energy formula and the impact force formula it is easy to see that achieving high velocity on impact is a sure way to significantly increase the power of your punches. Here we can see the relationship between velocity and how powerful a punch is as measured by its impact force (distance and mass are fixed):

Punch impact force depending on velocity on impact

The numbers were calculated using our impact force calculator which you can use with your own input to check all calculations.

So, in theory increasing the velocity seems like a great solution if you are looking to punch harder. Explosive power training and proper relaxation before the punch should therefore result in harder punches. There is also a fixed component here – reach. Kimm & Thiel [1] found reach to be significantly correlated to velocity on impact:

The correlation between reach and velocity suggests that athletes with a greater reach can generate faster punches. This is plausible, because the further the hand travels, the more time there is to accelerate even though the fist may take a longer time to reach its target.

Fighters with longer arms, assuming equal training and relaxation technique, have an inherent advantage in punching power over opponents with smaller reach.

Can you increase punch velocity?

We’ve seen how it works in theory, put is it possible to increase velocity to a significant extent in order to punch harder in practice? Several studies suggest that professional athletes are not able to achieve speeds significantly faster than those of amateurs or even untrained control groups [2,3]. The differences observed there were in the 25% range for both studies (10.4 m/s vs 12.4 m/s in [2], 5 m/s vs 6.7 m/s in [3]).

At most, fist velocities achieved by professionals were 50% times higher, e.g. according to the data of Kimm & Thiel [1] an inexperienced fighter hits with a velocity of ~5.25 m/s on average whereas the average for more experienced fighters was ~7.6 m/s. However, they were using an experimental device for measuring the speed, so it is unclear how reliable their results are.

Even though the information here is a bit contradictory, it seems certain increases in punching velocity are indeed possible in practice. If we take the 25% number as a more reliable and realistic upper limit on how much one can improve on the speed of their fist, then following the impact force formula we can conclude that simply by increasing velocity one can punch about 56% harder. Due to the geometric relationship we get a non-linear increase in punching power which means a modest increase in velocity results in much heavier punches.

Therefore, having longer reach, explosive power training, and proper relaxation of the muscles before a punch should help you get an edge and punch harder.

Increase punching power by putting more mass behind the punch

Despite being just linearly related to impact force, the mass behind a punch can have a great effect on the power delivered. Here is the relationship between the mass thrown into a punch and its impact (velocity and duration fixed):

Relationship between punching power and mass behind the punch

We gain less for each step-wise increase in mass (1 kg ~= 2.2 pounds). For example, going from 1 kg to 2 kg leads to doubling the force of the punch.

However, there seems to be evidence that much of the edge in punching power achieved by professional boxers and other martial artists comes from their ability to put more mass behind their punches. This is a conclusion expressed in Smith & Hamill [2], Neto et al. [3] Cheraghi et al. [4] It is possibly an implied conclusion from Bergün et al. [5] where the increase in punching power in orthodox versus southpaw stance is attributed to greater rotation of the trunk which likely translates in both increased velocity and mass.

The only data on the relative difference between inexperienced and experienced fighters is presented by Neto et al. and it shows that experienced fighters were able to engage twice the effective mass compared to the control group (2.62 kg vs 1.33 kg).

In terms of ways to increase the effective mass and thus punch harder, Cheraghi et al. suggest leg work and core strength exercises:

“Fundamental to successful boxing performance is optimum punching force that could not be achieved without taking advantage of lower body motion. Leg drive has been observed to build-up momentum in the kinematic chain helping towards greater fist velocity and the effective mass. Therefore, specificity of strength training should focus on lower body kinematics.”

Neto et al. cite Blum (1997) in support of tightening specific muscle groups to achieve greater effective mass:

“The well-trained martial artists may achieve higher effective masses by tightening appropriate muscles immediately before the impact.”

and additionally, Pain and Challis (2002):

“…muscle tension reduced the intrasegmental motion by 50% during high-energy impacts, contributing to a decrease in the energy lost from the forearm during these impacts.”

Therefore, if you want to know how to punch harder, one answer seems to be: train for leg explosive power, core strength, and tense specific muscle groups during the impact in order to increase the effective mass behind the punch.

Having a greater body weight will also help according to a study by Waliko et al. [7] on Olympic boxers which is also weakly supported by data from Guidetti et al. [6] on middleweight boxers and Neto et al. [3] on kung-fu athletes.

Faster energy release for maximum punching power

Something which I don’t think has been explored before is the possibility to increase punching power by decreasing the impact distance or, equivalently, by decreasing the duration of the impact. What this means is that if the same amount of force in terms of velocity and mass is released in a shorter duration / distance, it will result in a much stronger punch.

Here is a graphical examination of the relationship of punch force and impact distance:

Relationship between punch force and impact distance

and punch force and impact duration:

Relationship between punching power and impact duration

Decreasing the impact duration below a certain threshold leads to disproportionately high increases in punching power. Similarly, this holds for impact distances below a certain threshold. Both graphs agree with each other as impact duration is a linear function of impact distance, assuming everything else is fixed.

How does one go on to achieve this compression of the punch in a smaller time frame / smaller distance? In practice this means that ones’ effective mass behind the punch should decelerate from a significant velocity to zero while also conducting all of it into the opponent. It seems that in order to achieve that, one needs to tighten their muscles exactly at the point of contact in order for the impact to transfer as much energy forward in a tiny amount of time.

The above might be hinted at in the above-mentioned papers by Blum and Pain and Challis where they speak of decreasing energy loss by tightening of the muscles at the time of impact. The specific technique of executing this muscle contraction is unclear, but it seems like contracting as many muscle groups as possible at the same time would result in a punch with maximum power.

If I were to speculate on the secret behind being able to throw powerful punches from a short distance where you don’t have enough time to reach high velocity, I’d say that it is a combination of engaging more mass and achieving an extremely fast energy release.

How to punch harder

This article examined the physics behind throwing a punch, reviewed key factors for having a more powerful punch, and looked at what the scientific literature says about ways to increase punching power. To achieve the maximum impact force possible with your body structure, you need to improve on the velocity of your fist on impact, the effective mass behind the punch, the speed of energy release, and the precision of the fist and arm alignment.

While heavier fighters and fighters with a longer reach have a natural advantage in possessing a stronger punch other things being equal, all fighters can improve their fist velocity, effective mass, and speed of release by:

  • explosive power training, especially for the leg muscles (velocity)
  • proper whole-body relaxation before and during the punch (mass and velocity)
  • core strength isometric exercises to facilitate whole-body engagement (mass and velocity)
  • tightening of the entire body on contact (mass, speed of energy release)

Combined, these will lead to significantly harder punches. Furthermore, improvements in your strike precision / alignment will mean more of the achieved power will impact your target. Hitting at an angle decreases the effective impact following the laws of vector geometry. Specific exercises for this are beyond the scope of the article.

Here is an example of the expected increase in punching power, taking realistic numbers from Neto et al.:

Fighter TrainingEffective Mass (kg)Velocity (m/s)Impact Duration (s)Peak Force (kN)Difference
No training1.335.040.0101.340 (calc)N/A
Mass & Velocity Improved2.626.670.0103.548 (calc)265% (2.65x)
Mass, velocity & impact duration improved2.626.670.0084.436 (calc)331% (3.31x)

In this scenario a trained athlete can produce more than 2.5 times more powerful punches than an untrained person. If a 20% improvement in impact duration is also possible, then that’s 25% better than the above, leading to a 3.3 times harder punches when compared to an untrained person.

Sounds like a good payoff for the hard training, if done right.

References

[1] Kimm D., Thiel D. (2015) “Hand Speed Measurements in Boxing”, Procedia Engineering (112) p.502-506, DOI: 10.1016/j.proeng.2015.07.232
[2] Smith P.K., Hamill J. (1986) “The effect of punching glove type and skill level on momentum transfer” Journal of Human Movement Studies (112) p.153-161.
[3] Neto et al. (2007) “The role of effective mass and hand speed in the performance of kung fu athletes compared with nonpractitioners” Journal of Applied Biomechanics 23(2) p.139-48, DOI: 10.1123/jab.23.2.139|
[4] Cheraghi et al. (2014) “Kinematics of Straight Right Punch in Boxing” Annals of Applied Sports Science 2(2) p.39-50 DOI: 10.18869/acadpub.aassjournal.2.2.39
[5] Bergün et al. (2017) “The effects of impact forces and kinematics of two different stances at straight punch techniques in boxing” Archives of Budo Science of Martial Arts and Extreme Sports (13) p.35-39
[6] Walilko et al. (2005) “Biomechanics of the head for Olympic boxer punches to the face” British Journal of Sports Medicine 39(10), p.710-9 DOI: 10.1136/bjsm.2004.014126
[7] Guidetti et al. (2002) “Physiological factors in middleweight boxing performance” The Journal of Sports Medicine and Physical Fitness 42(3), p.309-14

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This entry was posted in Science, Sports and tagged , , , , , , , . By Georgi Georgiev
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