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Effects of weight in punch resistance and power in boxing?

  1. Aug 1, 2017 #1
    I wasn't exactly sure which forum I should post this question in but I felt this was the most appropriate one. So if there is a more appropriate one, feel free to relocate it (whoever is responsible for that).

    I wanted strictly a scientific answer to this question. How does weight affect a boxer's punching power and punch resistance? In boxing, boxers are divided into weight divisions. Weight can be composed of many things such as muscles, fat, bone size and etc. However, boxing doesn't factor in all of those separate things when dividing boxers into weight divisions. It doesn't matter what a boxer's weight is composed of. In the end, all boxers are divided by weight divisions (irrespective of how much of the weight is fat, muscles or anything else).

    So what I wanted to know was how much of an affect does weight have on a boxer's punching power and punch resistance. Do things like muscle mass, fat quantity, skull size and etc. matter as much as purely weight or is boxing correct in making those factors less significant? Does it scientifically matter whether a boxer is mainly made of fat or muscles or anything else when it comes to punch resistance and power or are these factors irrelevant or not as irrelevant as PURELY weight?

    Does a heavier person have greater POTENTIAL for power than a lighter person, irrespective of how fat or muscular they are? Does a heavier person (without taking into account the amount of fat or muscles) also have higher punch resistance than lighter people? If the answer is yes to these questions, then why / how would that be?
     
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  3. Aug 1, 2017 #2

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    I think that the place to start is to consider the momentum behind a punch. Suppose that two people throw the same punch with the same speed and form. The heavier person has more momentum behind the punch ( momentum = mass * velocity). On the receiving end, a person is knocked out by the acceleration of the head injuring the brain. A heavier person would absorb the momentum of a punch with less velocity. So his brain would not be bounced around as much as a lighter person's would.
     
  4. Aug 27, 2017 #3
    Proper punching technique should be factored in too. A smaller person with proper form from years of training can, in theory, hit harder than someone who is bigger but doesn't know how to throw his fists properly.

    Case in point Anderson Silva traditionally fights at 188 lbs yet went up a weight class to 205 lbs and knocked out three opponents in that division.

    In fact two of the fighters he KO'ed, Forest Griffin and Stephen Bonner fought each other in a slugfest. They punched each other for three rounds(15 mins) as hard as they could and neither could knock the other out. Silva took them both out in the first round with a single blow, despite being almost 20 lbs smaller.

    The Spider is known for picture perfect striking technique and accuracy. He is able to hit his foe in a precise location while in battle. And he is noted for maximizing power with no wasted motion; ie no big build up; winding his arms, etc etc.

    That being said if all things are equal than the bigger person would hit harder by utilizing the same technique just because he has more mass and presumably strength to back up his form too.
     
  5. Aug 28, 2017 #4
    How about punch resistance? What ways does having more weight help with absorbing punches better?
     
  6. Aug 28, 2017 #5

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    A larger person will gain a given amount of momentum with a lower velocity. That, and F=MA, means he will suffer lower accelerations and the jarring of the brain will be reduced.
     
  7. Sep 5, 2017 #6
    Thank you very much! Now it makes perfect sense!
     
  8. Sep 19, 2017 #7

    morrobay

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    Yes and in fact ring deaths and most serious injuries are in lightweights and lighter classes.
     
  9. Mar 14, 2018 #8
    I just wanted to ask another question in regards to that post you made. Does the weight of a person directly play a factor in the acceleration of the head when absorbing punches? If yes, how so? Does sufficient energy get transferred to the body in order to help absorb punches better?

    If most of the weight of a person is in their body, would that help that person absorb head punches better and how?
     
  10. Mar 14, 2018 #9

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    I think you are asking if a heavier person being punched in the head would have less acceleration because of the force being absorbed through the larger neck and body, in addition to the larger head. I guess that is reasonable. Although when I have seen the slow motion of a knockout punch it seems like his head moves fairly independently of the body, so that connection to the body doesn't help as much as one might imagine.
     
  11. Mar 22, 2018 #10
    Why does the power of a punch depend on if you follow through the motion, rather than just "arm punch" with twice the speed?

    Your body mass is not transfered to the fist, so what accounts for the 30% increase in power from a boxers slower, body twisting punch compared to Karate? Is it the deeper penetration?
     
  12. Mar 22, 2018 #11

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    I am not a boxing or sports expert, so I can only make an educated guess. A boxer's punch is faster because of the follow-through. The forearm moves relative to the body and the body is moving forward. So the velocities add to a higher total velocity. The weight of the gloves also makes a difference and moving the body forward helps to propel that total glove/forearm mass forward.
     
  13. Mar 22, 2018 #12
    My point is that the boxing punch is NOT faster, yet packs 30% more power with the body following through the motion, with or without gloves. A Karate punch with a slight hip jerk is delivered faster, yet is 30% less powerful from the same exponent according to studies.
     
  14. Mar 22, 2018 #13

    jim mcnamara

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    Okay, @Pleonasm Better, please cite a study. It is our policy.
     
  15. Mar 22, 2018 #14

    http://www.raynerslanetkd.com/ARTICLES_Patterns_Sinewave.html

    Power Generated By Taekwon-Do Techniques By Use Of The Sinewave
    by Tim Murphy



    "Testing was conducted to measure the power generated using various Taekwon-Do techniques. The aim of the test was to compare different methods of performing the techniques, namely using sine wave and without using sine wave."

    Boxing style punch
    Subjects were required to assume a regular boxing style stance and punch from their back hand using standard boxing technique (i.e. hands up, chin down, turning shoulder into the punch etc). On average, this type of punch was found to be 30% more powerful than the traditional punches.

    Limitations of the testing
    Only two test subjects were used in the test. To obtain more accurate and comprehensive results a larger number of people would need to be tested.

    If it's the same people performing both techniques, I don't see any harm with the study. Especially if non boxers (Karate/Taekwondo black belts) still punched harder with boxing style punch. It couldn't be more clear then.
     
  16. Mar 22, 2018 #15
    More fluid in your brain. But really the size of your head is said to make the most difference. Your neck muscles are stronger if it has to hold up a heavy brain, and neck muscles determine how perceptible you are to be rendered unconscious.
     
  17. Mar 22, 2018 #16

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    @Pleonasm , I see the statement about the boxing punch being more powerful, but I don't see any velocity information about the boxing punch. Maybe I missed it.
     
  18. Mar 22, 2018 #17
    There's greater acceleration involved in the boxing punch, since it's a longer sequence (turning the shoulder into the punch). Maybe that's why the punch is 30% more powerful? The velocity in the Karate style punch is usually higher but it's a shorter, snappier sequence.
     
  19. Mar 22, 2018 #18

    jim mcnamara

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    @Pleonasm
    What people are asking for is Physics, actually. There are articles out there on kinesiology, biomechanics, and exercise physiology, see if you can find one of those.
    Here is something a tad more scientific: https://arxiv.org/pdf/1010.2658

    You can do better than the above pdf, but it is interesting. And does cite better quaility studies.
    Which is what PF is all about.
     
  20. Mar 22, 2018 #19

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    We need to be careful here. The term "shorter, snappier" may not mean higher velocity, it might just mean quicker reaction. Something can build slowly to a higher velocity. It's the velocity at impact that counts. Acceleration and jerk only counts if they lead to a greater impact velocity.
     
  21. Mar 27, 2018 #20
    Heavier weight allows more muscle, which is useful for delivering more powerful punches and also for resisting blows to the head.
     
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