Contributing factors to punching power in Boxing

A narrative review summarizing determinant factors of punching power

in boxing and means of improving them

Saman Monfared

Examensarbete, 180 hp

Tränarprogrammet, Examensarbete för kandidatexamen i idrottsmedicin, 15 hp

Vt 2020

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Abstract

Power is a complex area to study and is dependent on a great multitude of factors. Despite

this, power-development is of interest in boxing. The purpose of this literature study was to

analyze various factors that contribute to punching power in the sport of boxing and to

provide a basis for improving it. Original and review articles ranging from the years 1963 to

2017 were retrieved from various databases (e.g., PubMed and Google Scholar). Out of 145

reviewed titles and abstracts, 79 of those met the criteria and were included in this review.

Only articles related to power-development were included. The contributing components that

were analyzed in this study were the following: force production, velocity production, high

velocity strength, stretch shortening cycle, intention, and inter-intramuscular skill &

coordination. Additionally, systematic planning strategies such as periodization and mixed

methods approach were analyzed. It was concluded that all components are interdependent

and positively affect the upper -and lower body power-production of athletes (and punching

power consequently). Further empirical research on boxing-specific power development is

still required.

Keywords: boxing, punching power, power training, muscle power, force

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Table of contents

Abstract ..................................................................................................................................... 1

Introduction .............................................................................................................................. 4

What is boxing? ................................................................................................................. 4

Physiological requirements of boxing and the importance of power ........................... 4

Previous research .............................................................................................................. 5

Purpose ............................................................................................................................... 5

Problem statements ........................................................................................................... 5

Hypothesis .......................................................................................................................... 5

Method ....................................................................................................................................... 6

Inclusion criteria ............................................................................................................... 6

Exclusion criteria .............................................................................................................. 6

Ethical approach of selecting articles .............................................................................. 6

Selection process ................................................................................................................ 7

Results ....................................................................................................................................... 8

Mechanics behind a punch ............................................................................................... 8

How punching force is measured and analyzed ............................................................. 9

Force-production ............................................................................................................. 10

Velocity-production ......................................................................................................... 11

High velocity strength ..................................................................................................... 13

Stretch shortening cycle .................................................................................................. 14

Inter-intramuscular coordination and skill .................................................................. 15

Intention ........................................................................................................................... 16

Periodization .................................................................................................................... 16

Mixed methods approach ............................................................................................... 17

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Discussion ................................................................................................................................ 18

Previous research, shortcomings, and future research ................................................ 18

Training interventions and boxing performance ......................................................... 18

Technical proficiency and effective punching .............................................................. 21

Periodization and mixed methods approach ................................................................ 21

Ethical and societal reflections ....................................................................................... 22

Methodological reflections .............................................................................................. 23

Conclusion ........................................................................................................................ 23

Future research ............................................................................................................... 23

References ............................................................................................................................... 25

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Introduction

What is boxing?

Boxing consists of stand-up fighting with utilization of punching exclusively and should

therefore not be confused with other combat sports, such as: Muay Thai, MMA and

kickboxing. Fighters can only target the frontal or lateral areas of their opponents’ head or

torso (1). The duration and numbers of rounds varies in amateur boxing, depending on the

competitive level, and the gender. Novice boxers compete in three 2-minute rounds,

intermediate boxers compete in four 2-minute rounds, and open-class boxers compete in three

3-minute rounds (males) and four 2-minute rounds (female) (1). In professional boxing, lower

standard contests consist of four 2-minute rounds and an elite bout may consist of 12 three-

minute rounds. An athlete can win the bout at any time if he or she manages to knock the

opponent out; thus, reducing the duration of the bout. If no knockout occurs, the judges will

dictate the winner through a scoring-system; based on number of quality punches,

domination, technical and tactical superiority, and infringement of the rules (1).

Physiological requirements of boxing and the role of power

Although factors such as aerobic capacity and buffering capacity of lactate are of relevance

due to the enduring nature of boxing and the aforementioned timeframe (2,3,4,5), knowledge

regarding improvement of punching power is a sought-after area amongst athletes and

coaches in the world of combat-sports (5). Effective punching is not solely dependent on

muscular power, it is a complex movement that involves upper and lower body musculature,

and the proper coaction of agonist and antagonist musculature (1,6,7,8,9,10,11,12,13). There

exists a certain stiffening of appropriate musculature just upon impact that contributes to the

punching force, which experienced practitioners have been shown to utilize to a greater

degree (11,14,15). Therefore, technical aspects of punching are of importance. The athlete

that possesses superior punching power may achieve victory through ‘’knockout’’ and can

therefore dictate the match on his or her own terms (5,16) The importance of power can be

explained by Newton’s second law of motion; the motion of an object (acceleration) is

proportional to the forces applied to it. If greater forces are applied in a given time frame,

greater acceleration is expressed. Therefore, increases in both force and velocity will result in

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increase of power. Ultimately, in the context of sports, power can be described as force

multiplied by velocity of a particular movement (1,6,17,18,19,20,21).

Since punching power is dependent on not one but multiple factors (1,2,6,7,10,12), it seems

rational for athletes and coaches to divide those into manageable and practical procedures that

can be done in a periodized fashion. The so called ‘’mixed methods approach’’, which

includes utilization of multiple methods for achieving a certain goal (21).

Previous research

Various methods as means of increasing power behind a punch has been studied in previous

literature; among those are strength training, plyometric training, ballistic training, and

Olympic weightlifting to name a few (1,2,6,7,10,12). In addition, correlation between

punching power and high power and force output has been found among boxers (1). However,

I have yet to find a study that combines all those factors into a realistic and practical basis that

athletes and coaches can take into consideration.

Purpose

Through this study, I will aim to identify and assess factors that contribute to punching power

and to provide athletes and coaches a new understanding for training specific to this goal.

Problem statements

1. What are some contributing factors to punching power in the sport of boxing?

2. What training methods can one utilize to increase punching power?

Hypothesis

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1. I hypothesize that factors such as force-production, velocity-production, high velocity

strength, stretch-shortening cycle, intention, and inter-intramuscular coordination and

skill will contribute to punching power. Furthermore, I hypothesize that no one athlete

has the same needs of improvement regarding the aforementioned factors of power-

development-

2. Each factor as mentioned above can be improved though an appropriate training

method that can be executed in a training facility. For planning the implementation of

the training methods of power-development, I assume a mixed-methods approach with

the use of a periodization-system will be effective.

Method

Original and review journal articles were retrieved from PubMed. Additional searches were

conducted in the search engine Google Scholar. The search strategy included the terms

‘punching power’, ‘boxing’, ‘strength and conditioning boxing’, ‘boxing power, ‘knockout’,

‘punching power’, ‘punching force’, ‘plyometrics’, ‘ballistic training’ and ‘power

development’. References from the original studies were searched for information of further

relevance. Both old as well as newer articles were included in this study, ranging from 1963

to 2017.

Inclusion criteria

Of all the articles found, only those that contained scientific methodology and proved relevant

to power development and the sport of boxing were included. I included qualitative- and

quantitative studies; descriptive, exploratory, explanatory, evaluation, and experimental. The

statistical methods in the analyzed studies included hypothesis testing, standard deviation, and

regression. I included a balance of old as well as newer articles relevant to the problem

statements (1963 to 2017).

Exclusion criteria

I excluded abstracts (alone) and any work of anecdotal nature. For instance, expert opinions,

studies based on charts and questionnaires exclusively, and essays without scientific backing.

Ethical approach of selecting articles

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Ethically questionable works were excluded, such as: animal studies, work of violent or

harmful nature (physically or psychologically), studies lacking informed consent and

unapproved personal data collection.

Selection process

The experience levels of the subjects relevant to the studied phenomenon were of variance; I

wanted to include both trained and untrained subjects. E.g., if the purpose were to measure

how a strength-training intervention affects power production; I have included studies that

were done on both experienced and lesser experienced individuals. Studies made on athletes

from other sports with similar movements to boxing were included. I initially read the titles,

abstracts, and methods to see if those fulfilled the criteria. If those were considered legitimate,

I further analyzed the rest of the content for information relevant to the investigation.

Manual search of reference lists

(n = 41)

Reviewed titles, abstracts, and methods

(n = 145)

Excluded articles

-Did not fulfill the inclusion

criteria

(n =66)

Studies that were included

in this review

(n =79)

Articles found in the data-base

search

PubMed (n = 54)

Google Scholar (n =50)

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Results

Mechanics behind a punch

Effective punching is a complex movement that is dependent on the coaction of the arms,

trunk, and legs (12). When Filimonov et al., (7) analyzed boxers with superior punching

power, it was observed that the lower body is the biggest contributor. Additionally, when they

observed ‘’knockout artists’’ (category of boxers with a track-record of knockout victories)

compared to other boxing-styles, it was concluded that leg musculature was the biggest

contributor to punching power amongst the knockout artists. They further assessed elite,

intermediate and novice boxers and found out that in experienced boxers, the legs contributed

to 38.5% of the punching force, meanwhile the values were 32.2% and 16.5% for the

intermediate and novice boxers respectively.

When boxers punch at high velocities, the ability to transfer forces from the lower body-

extremities to the arms are of high importance when striving to achieve high punching power

(1,7,10,12). Additionally, leg musculature contributes to hand velocity during punching

movements (12). Giovani and Nicolaidis (8) observed that in club-level amateur boxing,

upper- and lower body power is associated (r=0.70) as boxers with high power output in the

lower extremities also display high power output in the upper extremities. This is consistent

with previous research as presented in this section. The studies above further highlighted the

importance of appropriate training of the leg-musculature and proper biomechanics of shifting

weights if the goal is to increase punching force. To increase leg-drive for the boxing punch,

it is often recommended that one implements compound strength exercises (e.g., squats),

weightlifting movements (snatch, clean, jerk, etc.) and plyometric exercises (7,12). Those

movements are sometimes criticized for not being sports-specific enough for boxing; mainly

because they are mostly performed bilaterally and in the vertical direction. Until further

research is done, those guidelines will remain intact (10). With this argument in mind,

coaches must also be aware of how far they are willing to go with the concept of sport-

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specificity, as they run the risk of over-emphasizing the idea of it rather than getting

productive work done with athletes (22).

How punching force is measured and analyzed

Monitoring of punching force is relatively rare in combat sports. It may be implemented to

measure the effectiveness of a training program and as a filtering process to categorize boxers

with high power (10). There are various methods to measure punching force (N) in combat

athletes (see table 1); including water-filled bags with pressure transducers, force sensors

imbedded in boxing gloves and more (10). The most common method is piezoelectric force

transducers embedded in a target (23,24,25). Furthermore, piezoelectric force transducers are

desired for their practicality and reliability; their coefficient of variation is 1.8% to 3.6% (26).

Table 1: Methods for measurement of punching power from various studies

Study Subjects Measuring equipment Type of punches tested

Punching force (N)

Atha et al.

Professional heavy weight boxer (n = 1)

Padded pendulum equipped with piezoelectric force transducer

No data 4 096 (Peak force)

Smith et al. Elite (n = 7), intermediate (n = 8), and novice (n = 8) boxers

Wall-mounted force plate (4-triaxial piezoelectric force transducers) with a boxer manikin cover

Elite rear hand mean force

4 800 ± 227

Elite front hand mean force

2 874 ± 225

Intermediate rear hand mean force

3 722 ± 133

Intermediate front hand mean force

2 283 ± 126

Novice rear hand mean force

2 381 ± 116

Novice front hand mean force

1 604 ± 97

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Girodet et al.

Karateka (n = 1) Makiware equipped with 2 single-axis force sensors

Straight punch 1 745 (peak force)

Pierce et al. Professional boxers; body weight 59 to 98.9 kg (n = 12)

Bestshot force sensor imbedded in boxing gloves

No data 866.6 – 1 149.2 (Mean force)

5 358 (Peak force)

Another accepted method to assess punching power is the shot-put test (the pushing of a

spherical steel ball for distance). Due to its practicality and similarity to a boxing punch, it can

be used to assess the development of punching power before and after a training intervention

(27). Punching power can be assessed during competition (live action) or in a laboratory.

Generally, they will differ due to the dynamic nature of boxing. For practical reasons, it is

most common to perform tests in a laboratory if development is to be measured over time

(10).

Force-production

Force-production is mainly developed through various strength-training methods. Force

production is regarded as the ability of the muscle to produce maximal force, or torque,

independent of time. Another term for this is ‘’slow velocity strength’’ or ‘’maximal

strength’’ (20).

Several studies have concluded that various strength-training methods lead to an increase of

contraction speed – a component of punching power (28,29,30,31). The main purpose of

strength training, however, is maximal force-development, which is a component that

contributes to overall power (2). Studies have been made on boxers with superior punching

power and predictably, they found out that those boxers perform better in various strength –

and power measurement tests compared to their lesser powerful counterparts (1).

To increase force-production, one may introduce compound lifts, e.g., back squat, and bench

press (21). Those will emphasize multiple muscle groups simultaneously, which may be

productive for boxers with an already busy schedule due to their sport (6). Compound lifts are

unique in that they are integrated across multiple joints (21). For maximal strength training,

athletes must train at an intensity that requires high peak force output. For several compound

exercises, this is achieved anywhere from 80 to 90% of the athlete’s one repetition maximum

(1RM) (32,33). With regards to core training and its usefulness to punching, emphasis needs

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to be made on lumbar stability and trunk rotation. This will enhance the ability to transfer

forces from the lower-body into the upper-body before making contact with the opponent

(35,36).

Force-production is a contributor to explosive power because it contributes to the force-

portion in the power continuum. However, when actions are done in high velocity, slow

velocity strength has limited ability to affect high forces at rapid shortening velocities

(37,38,39). The rationale is that strength training increases power, as power is a product of

force multiplied by velocity. In other words, if the athlete increases his or her 1RM strength in

a given lift, improvements in explosive power can follow. To truly improve power output

however, both force and velocity are of necessity (21).

There will be different adaptations following a resistance training program (21) depending on:

the intensity and the performed velocity of the given exercise (see table 2). Strength training

with heavy resistance and slow velocity of the concentric portion will target the high

force/low velocity portion of the force-velocity curve (see figure 1). Strength training with

lighter resistance but maximal velocity of the concentric action will target the velocity portion

in the curve; otherwise known as ‘’rate of force development’’ (21).

Table 2: Compound lifts (e.g., back squat) at various intensities and their impact on the force-velocity relationship

Intensity (% of 1RM) Velocity of movement Type of training

80-100% Slow Slow-velocity strength

60-80% Medium High-velocity strength

30-60% Fast Velocity production

Strength training with heavy resistance needs to be planned appropriately for the athlete who

lacks it. It can also be done in conjunction with velocity-based training so that the velocity-

production of the athlete is not negatively affected (40,41).

Finally, with any increase in muscle size due to strength training, muscle strength is also

accompanied (42). If we introduce the appropriate power training in conjunction with

hypertrophy training, the total power in proportion to body weight will be increased (21).

Velocity-production

Velocity production, otherwise known as ‘’rate of force development’’ (RFD), is the athlete’s

ability to produce rapid muscular actions with minimal to no external resistance (43). Once an

adequate strength base has been established through previous strength training, the athlete

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will generally be very responsive to velocity-specific training (43). It is however difficult to

assess what counts as adequate strength before one is ready for velocity training. Although the

literature is conflicting, some studies suggest being able to perform a back squat equal to two

times the body weight before implementing velocity-based methods (e.g., plyometrics) (43,

44).

The contraction of a boxing strike happens very briefly. In experienced boxers, it can happen

anywhere under 300ms (45). However, it generally takes >300 milliseconds for maximal

forces to be generated (46,47,48). Therefore, we also need to implement velocity training.

Velocity along with accuracy are two important factors that contribute to punching power and

are often a central factor in coaching (49). To achieve the highest possible power, the muscle

must produce the highest amount of force in the shortest amount of time possible. This can

partly explain the ineffectiveness when performing heavy-resistance training alone for the

purpose of explosive power development; force production alone is not adequate (50). Thus,

when training RFD, the same amount of force that previously took longer time to express will

be produced in a shorter time frame.

In general terms, as the resistance is increased, the speed of the movement is decreased. When

an athlete performs a lift in the weight-room with maximal resistance, the velocity of the

movement is often slow. As the resistance is decreased, the velocity of the movement is

increased, and the velocity portion of the power-continuum is targeted (21) (see figure 1).

Figure 1: The relationship between force and velocity

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Plyometrics, Olympic weightlifting and Ballistic training are all examples of appropriate

total-body training methods that can improve the velocity portion of the power continuum

(51).

Turner et.al (12) suggests an emphasis on ballistic training to improve velocity of strikes. For

instance, explosive jump training (e.g., back squat jump) with a resistance of 30 to 60% of

1RM is one example of such training protocol for increased RFD (40,52).

For athletes with mediocre fitness, a combination of plyometric- and compound strength

exercises has good potential for power development in the lower extremities. In their study,

Adams, K. et al., (17) compared the lower-body power development among forty-eight

subjects with less than one year strength-training experience. One of the groups was to

perform strength training exclusively, the other plyometrics, and a final group did a mixture

of both training methods. The mixed group developed significantly more power in the lower

extremities.

High velocity strength

High velocity strength is regarded as velocity production under loaded conditions; a

combination of force and velocity training (21). Those two components are usually

emphasized individually (as previously discussed), but through high velocity strength

training, the two components are emphasized simultaneously. Examples of appropriate

training methods are Olympic weightlifting techniques and ballistic training at higher

intensities (21).

Depending on the exercise, high velocity strength usually occurs at intensities around 50% of

1RM or less, i.e., squat and jump squat (53). Olympic weightlifting movements however are

unique in that they allow for high power output despite higher intensities (60% and beyond)

(54).

Numerous coaches are advocates of Olympic weightlifting for power-development of

athletes, with the rationale that Olympic weightlifters are capable of producing high amounts

of power (19,55). Numerous studies have been made on Olympic weightlifting and

performance improvements of power-athletes from various sports (18,19,56,57). As

previously mentioned however, high velocity strength (power) can be achieved through other

methods as well; it does not have to be Olympic weightlifting exclusively. However, the

intensities at which peak power is achieved vary between methods (32).

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Although characteristically slow-velocity strength exercises (i.e., squat, bench press, and

deadlift) have their place in the pursuit of power-development, Garhammer (19) observed that

the body expresses a superior power-output when performing high-velocity Olympic

weightlifting movements (snatch, clean, jerk and its variations).

Some studies highlight problems with traditional means of increasing strength and power

through compound movements (58,59,60). For instance, when doing compound lifts (light or

heavy resistance) at a faster velocity to make them sport-specific, the deceleration phase of

the lift is increased (61). The supposed problem is that athletes need to break at the end of the

lift to complete the lock-out with ease. The rationale is that many sports stress a need of high

velocity throughout the whole range of motion and that traditional compound lifts will only

emphasize this partially (21).

Accordingly, this concern with the partial deceleration phase could be overcome with ballistic

resistance training. The athlete will now jump with or throw the weight instead of stopping

completely at the end of the spectrum. For instance, instead of a bench press, a bench press

throw can be executed. Both heavy (>80% of 1RM) and light resistance <60% of 1RM) can

be used for ballistic training, depending on what the boxer lacks in the power-continuum.

Various studies have observed that an intensity of 30% is optimal for power development (39,

59). Kaneko et.al. (39) analyzed the effects regarding increases in rate of force development

from different training intensities. Subjects were instructed to perform lifts as quickly as

possible; with intensities ranging from 0, 30, 60, or 100% of their one repetition maximum.

Predictably, the results showed that the heavy resistance group increased their isometric

strength while the 0% resistance group increased velocity to a significant level. However, the

30% group produced the greatest overall power (strength expressed in a fast manner).

Loturco et al., (1) observed that punching impact is highly correlated with strength and power

qualities. When they analyzed boxers with high punching power, it was observed that they

also possess good results in movements such as the Squat jump (SJ), countermovement jump

(CMJ), bench throw (BT) and the bench press (BP). Those are all exercises that target

different spectrums within the force-velocity curve and are generally considered good

indicators of power in the lower and upper-body extremities.

Stretch shortening cycle

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The stretch shortening cycle (SSC), sometimes referred to as reactive strength, is one’s ability

to utilize elastic energy. This phenomenon has been observed in punching (12) and other

similar movements (62). Elastic components within the muscle and the tendon are stretched

when the muscle is loaded (63). It has been observed however that the tendon itself is the

main contributor to storage of elastic energy (63,64,65).

To utilize stored elastic energy in the muscle, one must change very briefly from an eccentric

(stretching) contraction to a concentric (shortening) contraction (66). This ability will enhance

the tendons of the muscle to produce maximal force in the shortest amount of time possible

(58,67). Bosco et al (68) compared the height differences between a jump initiated from a

static position (JS), and the counter movement jump (CMJ); which is initiated after the athlete

makes a preparatory dip. The CMJ was proven to be 18 to 20% higher than the JS, which

highlights the benefits of utilizing stretch forces to improve power production. There is

however a limit at which the stretch forces will be too great, and the Golgi tendon organ will

inhibit the movement, which consequentially will decrease the power production; therefore,

the right amount of stretch force is required for optimal effect (69).

Inter-intramuscular coordination and skill

To increase power production, it is required to have an optimal interaction between the

agonist- and antagonistic musculature involved in the specific movement. To perform an

action with fast velocity, the corresponding antagonist musculature needs to be relaxed (70).

By technical training specific to the movement itself (punching technique in this case), we

will achieve the optimal relationship between agonist and antagonistic musculature and

therefore increase power output (42). We can conclude that the more technically experienced

the boxer, the better the muscular coordination and potential for power output, which was

confirmed in a study conducted by Smith et al., (25). The punching power of three groups of

boxers with different levels of experience were analyzed: elite, intermediate and novice. For

the elite, intermediate and novice boxers, respectively, the maximal punching forces (mean - s

x ¥) were 4800 - 227 N, 3722 - 133 N and 2381 - 116 N for the straight rear hand punch

(commonly known as ‘’cross’’ in boxing terms). The results are consistent with other studies

regarding the correlation between training experience and punching power (9,71).

McGill et al., (11) observed a double peak in muscle activation when punches are thrown.

This double peak accordingly enhances velocity and force. Before a fighter throws a punch,

an initial peak is activated to enhance stiffness and stability throughout the body. This creates

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a momentum for the muscles to undergo a muscular relaxation phase, which increases

velocity. A second peak was made upon contact with the target, it was stated that this would

increase stiffness throughout the body to increase effective mass behind the punch and

therefore higher punching force.

Smith and Hamil (15) observed that skilled boxers are better at utilizing this effective mass.

Neto et al., (14) also concluded that effective mass is of importance in punching power, which

requires stiffening of appropriate musculature upon impact.

Intention

When training for explosive power development, it appears to be of importance that the

practitioner is performing the given exercise with the intention of high power. Whether the

practitioner is performing Plyometrics, Olympic weightlifting or any other endeavor for

power or velocity-based development, anything short of fast and powerful intentions may

only give mediocre results (52). It appears that the intention to move quickly affects the

velocity-specific response and adaptation (52). When one performs a lift with an intensity

close to 100% of 1RM, the practitioner must use maximal effort out of necessity. However, if

a plyometric jump or medicine ball throw is performed, the athlete might voluntarily reduce

the intensity of the movement, which will limit the performance improvements from the

exercise (21).

Jiang et al., (72) investigated the results of voluntary muscle action on athletic improvements

following an exercise program. Eighteen healthy participants were redirected to three

individual groups: high mental effort (HME), low mental effort (LME), and a control (CTRL)

group. Training lasted for 6 weeks (15 min/day, 5 days/week). At the end of the program, the

strength-levels were measured through an elbow-flexion machine. The HME group gained

20.47 ± 8.33% (P = 0.01) strength while the LME and CTRL groups had insignificant

improvements (1.89 ± 0.96% and − 3.27 ± 2.61%, respectively; P > 0.05), despite the same

intensity (30% MVC) for all groups.

Periodization

With such a great multitude of components to address for athletic development, appropriate

planning is often made based on the athlete’s strengths and weaknesses (7). Each component

of power-training can be emphasized in a specific block before moving on to the next. Such

approach is commonly known as Periodization (73). Some components may be of greater

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importance than others at a given time; strength training, for instance, affects power in a

hierarchical manner with effect diminishing as the importance for other factors become more

evident (42,74).

There exists countless terminology that describes different concepts of periodization models;

Linear Periodization is possibly the most common term (73). By following the linear

periodization model, muscle hypertrophy training is initially emphasized and is later

transitioned into a maximal strength cycle and finally ends with a cycle of power-training.

Lenetsky et.al (10) recommends this approach.

Mixed methods approach

Different interventions will affect the force-velocity curve in different ways. For instance,

heavy resistance training increases the ability to generate peak force, while velocity-specific

interventions such as ballistic training increases the overall rate of force development (3).

Table 3 provides a summary of all the studied components specific to punching power and

their corresponding training interventions. All the training interventions are interdependent

when it comes to power development (3,17,18,21,39,41,53,75).

Table 3: Components specific to punching power and their corresponding training intervention

No. Component Training intervention

1 Force production (Slow velocity strength) Strength training through compound

exercises with high intensities

2 Velocity production (Rate of force

development)

Ballistic training, plyometrics, and

compound exercises with low intensities

and high velocity of movement.

3 Power (High velocity strength) Olympic weightlifting variations and ballistic

training at higher intensities.

4 Stretch Shortening Cycle Plyometric movements: e.g., depth jump

and medicine ball throws with emphasis on

brief contact times

5 Intention Perform each exercise with powerful

intentions, as this increases the adaptation

6 Inter-Intramuscular coordination and skill Learn the proper mechanics for a powerful

punch

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Discussion

Previous research, shortcomings, and future research,

Currently, research regarding development of punching power for boxing is very scarce,

despite being a topic of interest in the community. Majority of the available research is

directed towards power training as a whole; not punching specifically. Further research is

required in this area.

Although countless of studies have been made on different training interventions and their

results, oftentimes they are done on untrained individuals or those of minimal training

experience; this was observed in some of the literature in this study (17,39,44,52,59,60,72).

Individuals who possess lower levels of fitness will most likely see improvements throughout

the force-velocity spectrum regardless of the training approach. Research made on boxers of

the world-class who possess high levels of fitness is very scarce, we can assume that the

results after a training intervention might have differed in such a scenario.

Additionally, majority of the training interventions analyzed in this study were conducted in a

brief training period, only a matter of weeks. It is questionable if an adequate training

adaptation can take place in such a brief period. Longer-term studies are required in the

future, preferably on athletes of the world-class. For practical reasons, this may be very

challenging.

Training interventions and boxing performance

We have little control over the genetic predisposition of an athlete to develop power. Some

boxers will be genetically gifted with a superior power-output; one only needs to observe the

professional boxing scene to observe this phenomenon. Nevertheless, this does not mean that

power cannot be further improved through training. We cannot change underlying factors

such as genetics, but we can aim towards this genetic ceiling that all athletes uniquely

possess.

The absolute force production of an athlete can be improved through appropriate strength

training (1,2,3,6,39,41,72,73). The velocity production can be improved through plyometrics

and ballistic training (12,17,40,51,52). Proper muscular coordination that leads to increased

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power can be improved through technical training and coaction of agonist and antagonist

musculature (9,11,14,15,25,42,70,71).

It appears that the leg-musculature plays a significant role in punching power; therefore, it is

recommended that one implements strength exercises for the leg musculature especially

(7,12). In conjunction with strength-training, it may be productive to employ sport-specific

methods for velocity development, e.g., single or combination punches thrown onto the heavy

bag or pads with high velocity and rest periods specific to power-training. This type of work

can also be used directly after compound lifts to utilize post activation potentiation (PAP).

PAP can be described as a short-term improvement in performance as a result of previous

heavy loading (76).

In boxing, rotational movements are very frequent (9) and therefore horizontal and vertical

exercises exclusively are probably not adequate. Majority of the power-exercises discussed in

the literature misses this point. It may prove wise to include rotational power exercises (e.g.,

medicine ball throws) in addition to the vertical and horizontal power exercises.

It may be of concern for some boxers that strength-training might contribute to excessive

muscle hypertrophy and therefore have a negative impact on fluidity of movement. However,

with carefully planned dietary habits and training structure, this can possibly be controlled to

a certain extent where neural adaptations will remain the priority. It is worth to mention that

strength-training is not necessarily synonymous with mass-building and aesthetics (i.e.,

bodybuilding); it is probably easy for an inexperienced individual to confuse the terms. The

misunderstanding can be arbitrary, as bodybuilding is a discipline where aesthetics, mass and

often slow and sometimes partial repetitions are encouraged (34). Such approach may prove

counterproductive to boxing performance, where velocity and fluidity of movement at

different ranges of motion is of importance (4).

Various strength -and power methods can sometimes be perceived as complex. For instance, a

common concern is whether the implementation of Olympic weightlifting is worth the effort

needed for the athlete to learn the fundamental technique before they can be executed

properly. It should be noted that there exist simplified variations that can be performed if the

purpose is power development alone. Instead of performing the full lift (snatch and clean) for

instance, athletes can focus on the second pull exclusively, as this portion is where most of the

20

power is produced (19). Furthermore, there exists ballistic exercises (i.e., jump squat) where

similar power outputs have been recorded (32) those are likely easier to execute.

As previously mentioned, the stretch shortening cycle is the utilization of elastic energy for

improved performance (63,68); this phenomenon is evident in boxing punches (12). For

boxing, we could achieve this elastic energy through a quick twisting of the hips before

releasing the punch. This transition must be done quickly; otherwise, the elastic energy will

be released as heat (66). Since majority of the punching power comes from the lower

extremities (7), we can contemplate that lower body plyometrics will have high transferability

into punching power.

Countless of studies attempt to compare the effectiveness of different training interventions,

i.e., strength training vs. velocity training and light loads vs. heavy loads to name a few. The

coach and the athlete need to take into consideration the weaknesses of the boxer, as this is

where the margin of improvement will likely be the highest (21). Every training component

within explosive power development has its appropriate place; it should not be a matter of

which intervention is superior to the other. Using the literature reviewed in this article, we

need to address appropriate exercises for each factor (e.g., slow velocity strength & rate of

force development).

Regardless of which training intervention related to power-development that one chose to

incorporate, intention and high mental effort appears to play a critical role (21,52,72). When

higher mental effort is put forth on a given exercise, regardless of resistance, adaptation is

increased (72). With higher adaptation, we can contemplate that our chances of improved

punching power are increased as well. It may therefore be important that appropriate feedback

is given from a coach, a measuring device, or increased height or length targets, for the athlete

to put forth more mental effort.

Based on the observations in this literature review, one can speculate that the more powerful

athlete is also more likely to achieve superior results in competition. Power is one of many

factors contribute to boxing performance (1,2,5,6,7,12,16,23) and for an athlete striving for a

high level, any component that could possibly lead to success should be emphasized. One can

hypothesize that if a boxer is not accustomed to an effective power-training intervention from

before, the margin of improvement will be high.

21

Technical proficiency and effective punching

If one is to incorporate a power-training program for boxing, it is essential that the boxing

sessions themselves are not sacrificed for this purpose. Skill and technique are likely

paramount to boxing performance. Any improvements in athleticism will most likely not

prove productive if they are done at the cost of the skills and technical aspects of boxing. One

should understand that strength and conditioning is merely supplemental. This point becomes

even more evident if the boxer is a novice; then the fundamental technique and skill of boxing

is of utmost importance. A novice-boxer will likely lack proper muscular coordination and

skill specific to boxing (7).

For a casual observer, punching might appear as a simple movement that can be learned with

ease; the studies I analyzed indicate the opposite (1,7,8,10,12). It appears that powerful

punching in boxing is a complex movement that is dependent on coaction of agonist -and

antagonist musculature and the proper shifting of weights from one extremity to the other

(especially that of the leg-musculature). Additionally, I found out that there exists a certain

stiffening of appropriate musculature among experienced and hard-punching boxers, which

creates an effective mass that leads to higher punching force (11,15,50). Experienced boxers

are more technically proficient and punch more effectively when compared to their lesser

experienced counterparts (7). If boxers desire punching power therefore, it might be

productive to focus on technical proficiency initially (before shifting the focus to power-

training). Coaches need to stress those points when training their boxers (if the desire is

higher punching power); boxers need to initiate the punch with high velocity, proper coaction

of musculature and tighten the musculature just upon impact to create effective mass.

Periodization and mixed methods approach

Most likely, a boxer already has a busy schedule regarding to the art and skill of the sport

itself. If we were to emphasize all the components of power development individually, in the

same cycle, this would likely not be practical or productive, as minimal time would be left for

the sport itself. A periodization plan is of importance. Analysis on the boxer’s areas of

improvement needs to be made to determine which component(s) of the explosive power

continuum needs the most emphasis. For instance, if the athlete already possesses adequate

levels of strength, then further increases in this department will likely lead to none or minimal

increases in explosive power development (77,78,79). We can theorize that if a boxer has

22

gone through a period of strength training and developed an adequate strength base, the next

step will be to implement velocity-based training (41). Velocity is determined by the time

needed to complete a movement (43). If we implement methods to decrease the time needed

for a movement (a punch in boxing), we increase the power-output. Accordingly, power is a

complex area; every athlete has different needs, an over-generalized approach may not be

effective (59).

With those arguments in mind, we need to define periodization in a broader manner. Tudor

Bompa, PhD, and a well-known figure in periodization for sports, explains in his work (73)

that periodization is nothing other than a sequence of training periods to target specific

training objectives with the final goal to help prepare the athlete for a competition or an

important event. All the additional terminology describing the supposed sub-divisions of

periodization is simply made-up among the community of coaches and trainers. If an effective

periodization model is to be created, the following criteria needs to be addressed: the specifics

of the sport, the number or estimated number of competitions the athlete will participate in

one year, and the physiological characteristics of the athlete (73). We should also consider the

current season (off-season vs. in-season) before creating a plan. Off-seasons generally provide

with a bigger timeframe for athletic development. Power-training in conjunction with boxing-

specific technical training will most likely prove effective. Linear periodization is a popular

sub-division that is commonly used (10,73). However, Bompa explains that a truly linear

periodization is non-existent. Which is logical, as an athlete’s development is in all likelihood

too complex to be generalized and simplified into a predictable and linear approach. It is

doubtful if linear periodization is the optimal approach for experienced boxers, as such

approach concludes that all boxers have the same needs and areas of improvement. It appears

that strength training affects power in a hierarchical manner with effect diminishing as the

importance for other factors become more evident (42,74). A linear periodization model could

possibly prove useful if the boxer’s current fitness is difficult to assess or if he or she needs a

general ‘’all-round’’ approach.

Ethical and societal reflections

This study was conducted to increase knowledge regarding improved punching power for

boxing. Punching power is simply another component that boxers can add to their arsenal and

promote a sense of preparedness before a competition. As far as consequences with this

knowledge goes, increased punching power also promotes a higher chance of a knockout

23

occurring during matches – which consequentially might increase the risk of neurotrauma. It

is apparent that boxing is of violent nature and every participant should be aware of the

potential risks when participating in the sport. However, sanctioned matches will include

medical controls to judge the condition of an athlete prior to competition. Information on the

development of punching power is scarce, and boxers can therefore benefit from the

knowledge that it can be further developed to increase preparedness.

Methodological reflections

To gather relevant articles, I used the appropriate search terms relevant to the thesis (see

method). Additionally, references from the original studies were searched and included, this

practice is commonly known as snowballing. The advantage of snowballing is that I may find

a lot of literature about a subject in a brief amount of time with ease. The disadvantage is that

the searching is made retrospectively, therefore each source that is found will be older than

the previous one, and finally, I indirectly run the risk of sampling bias. To combat the

sampling bias, I especially looked for and included articles that I suspected contradict the

hypothesis; I encourage different points of view. The publishing period of the articles were of

significant variance (1963 to 2017). Consequently, due to the varying publishing periods,

procedures and methodology were also of variance; as sports science can be regarded as a

rapidly growing department. Admittedly, I might run the risk of outdated methodology and

potentially faulty test-results; we have likely advanced tremendously since the 1960s.

Regardless, the old articles were balanced out by more modern ones and if the content of the

research were considered scientifically valid and helpful to the investigation, they were

included (regardless of publishing period).

Conclusion

1. Out of all the extremities of the body, it appears that the leg musculature is the biggest

contributor to punching power. Power production (and consequently punching power)

is affected by force-production, velocity production, utilization of elastic energy

(SSC), and inter-intramuscular coordination and skill. The components are

interdependent, and it appears that they affect power in a hierarchical manner

depending on the individual athlete.

2. The components of power-production can be improved through various training-

methods. To increase force-production, one can introduce compound strength

24

exercises. For velocity production, one can introduce plyometrics, ballistic training,

and Olympic weightlifting. To improve the utilization of elastic energy, one can

introduce plyometric exercises with an emphasis on rapid eccentric to concentric

contractions. To improve inter-intramuscular coordination and skill, one must learn

proper coaction of musculature. Training adaptation from a given exercise may be

increased with higher mental effort. The planning and execution of all components can

be managed through a periodization system and a mixed methods approach.

Future research

Majority of the research on power-output tends to be broad. Research regarding as to how

power-training can be further specialized into boxing movements specifically is still limited.

Further empirical research is required, preferably with test subjects who are experienced in

the sport of boxing to a significant level; reason being that untrained subjects are likely prone

to improvement regardless of training intervention.

25

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