Post on 05-May-2022
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
1
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
2
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
3
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
4
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
5
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
6
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
7
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)
8
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-
9
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
10
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
11
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
12
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
13
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).
14
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
15
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
16
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
17
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
18
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
19
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
References
1. Loturco, I., Nakamura, F. Y., Artioli, G. G., Kobal, R., Kitamura, K., Abad, C. C. C., ...
& Franchini, E. (2016). Strength and power qualities are highly associated with
punching impact in elite amateur boxers. The Journal of Strength & Conditioning
Research, 30(1), 109-116.
2. Cordes, K. (1991). Boxing: reasons to strength train for amateur boxing. Strength &
Conditioning Journal, 13(5), 18-21.
3. Haff, G. G., & Nimphius, S. (2012). Training principles for power. Strength &
Conditioning Journal, 34(6), 2-12.
4. Slimani, M., Chaabène, H., Davis, P., Franchini, E., Cheour, F., & Chamari, K. (2017).
Performance aspects and physiological responses in male amateur boxing
competitions: A brief review. Journal of Strength and Conditioning Research, 31(4),
1132-1141.
5. Smith, M. S. (2006). Physiological profile of senior and junior England international
amateur boxers. Journal of sports science & medicine, 5(CSSI), 74.
6. Ebben, W. P., & Blackard, D. O. (1997). Developing a strength-power program for
amateur boxing. Strength & Conditioning Journal, 19(1), 42-51.
7. Filimonov, V. I., Koptsev, K. N., Husyanov, Z. M., & Nazarov, S. S. (1985). Boxing:
Means of increasing strength of the punch. Strength & Conditioning Journal, 7(6), 65-
66.
8. Giovani, D., & Nikolaidis, P. T. (2012). Differences in force-velocity characteristics of
upper and lower limbs of non-competitive male boxers. International journal of
exercise science, 5(2), 106.
26
9. Joch, W., Fritsche, P., & Krause, I. (1981). Biomechanical analyses of punching in
boxing. Opus cit.. Morecki A, Fidelius K, Kedzior K, Wit A. Biomechanics VII-B, 219-
225.
10. Lenetsky, S., Harris, N., & Brughelli, M. (2013). Assessment and contributors of
punching forces in combat sports athletes: Implications for strength and
conditioning. Strength & Conditioning Journal, 35(2), 1-7.
11. McGill, S. M., Chaimberg, J. D., Frost, D. M., & Fenwick, C. M. (2010). Evidence of a
double peak in muscle activation to enhance strike speed and force: an example with
elite mixed martial arts fighters. The Journal of Strength & Conditioning
Research, 24(2), 348-357.
12. Turner, A., Baker, E. D., & Miller, S. (2011). Increasing the impact force of the rear
hand punch. Strength & Conditioning Journal, 33(6), 2-9.
13. Wilson, G. J., Newton, R. U., Murphy, A. J., & Humphries, B. J. (1993). The optimal
training load for the development of dynamic athletic performance. Medicine and
science in sports and exercise, 25(11), 1279-1286.
14. Neto, O. P., Magini, M., & Saba, M. M. (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), 139-148.
15. Smith, P. K., & Hamill, J. (1986). The effect of punching glove type and skill level on
momentum-transfer. Journal of Human Movement Studies, 12(3), 153-161.
16. Pierce, J. D., Reinbold, K. A., Lyngard, B. C., Goldman, R. J., & Pastore, C. M.
(2006). Direct measurement of punch force during six professional boxing
matches. Journal of quantitative analysis in sports, 2(2).
17. Adams, K., O’Shea, J. P., O’Shea, K. L., & Climstein, M. (1992). The effect of six
weeks of squat, plyometric and squat-plyometric training on power production. Journal
of applied sport science research, 6(1), 36-41.
27
18. Armstrong, D. F. (1993). PROGRAM DESIGN: Power Training The Key to Athletic
Success. Strength & Conditioning Journal, 15(6), 7-11.
19. Garhammer, I. (1993). A Review of power output studies of olympic and powerlifting:
methodology, performance. J. Strength Cond. Res, 7, 76-89.
20. Knuttgen, H. G., & Kraemer, W. J. (1987). Terminology and measurement. Journal of
applied sport science research, 1(1), 1-10.
21. Newton, R. U., & Kraemer, W. J. (1994). Developing explosive muscular power:
Implications for a mixed methods training strategy. Strength & Conditioning
Journal, 16(5), 20-31.
22. Bennett, S. (2006). Sport Specificity: How Far Do You Take It?. Strength and
Conditioning Journal, 28(4), 29.
23. Atha, J., Yeadon, M. R., Sandover, J., & Parsons, K. C. (1985). The damaging
punch. Br Med J (Clin Res Ed), 291(6511), 1756-1757.
24. Girodet, P., Vaslin, P., Dabonneville, M., & Lacouture, P. (2005). Two-dimensional
kinematic and dynamic analysis of a karate straight punch. Computer methods in
biomechanics and biomedical engineering, 8(S1), 117-118.
25. Smith, M. S., Dyson, R. J., Hale, T., & Janaway, L. (2000). Development of a boxing
dynamometer and its punch force discrimination efficacy. Journal of sports
sciences, 18(6), 445-450.
26. Harris, N. K., Cronin, J., Taylor, K. L., Boris, J., & Sheppard, J. (2010). Understanding
position transducer technology for strength and conditioning practitioners. Strength &
Conditioning Journal, 32(4), 66-79.
27. Obmiński, Z., Borkowski, L., & Sikorski, W. (2011). The shot put performance as a
marker of explosive strength in polish amateur boxers. A pilot study.
28. Dengel, D. R., George, T. W., Bainbridge, C., Pleck, S. J., Van Handel, P. J., &
Kearney, J. T. (1987). 277: TRAINING RESPONSES IN NATIONAL TEAM
BOXERS. Medicine & Science in Sports & Exercise, 19(2), S47.
28
29. Fox, E. L., Bowers, R. W., & Foss, M. L. (1989). The physiological basis of physical
education and athletics. William C Brown Pub.
30. Koryac, Y. (1991). Assessing neuromuscular speed and speed-strength in
boxers. Soviet Sports Review, 26(4), 195-8.
31. Solovey, B. A. (1983). Exercises with weights as a means of improving hitting speed in
young boxers. Soviet Sports Review, 18(2), 100-102.
32. Cormie, P., McCaulley, G. O., Triplett, N. T., & McBride, J. M. (2007). Optimal
loading for maximal power output during lower-body resistance exercises. Medicine
and science in sports and exercise, 39(2), 340-349.
33. Peterson, M. D., Rhea, M. R., & Alvar, B. A. (2005). Applications of the dose-response
for muscular strength development: a review of meta-analytic efficacy and reliability
for designing training prescription. The Journal of Strength & Conditioning
Research, 19(4), 950-958.
34. Helms, E. R., Fitschen, P. J., Aragon, A. A., Cronin, J., & Schoenfeld, B. J. (2015).
Recommendations for natural bodybuilding contest preparation: resistance and
cardiovascular training.
35. Harris-Hayes, M., Sahrmann, S. A., & Van Dillen, L. R. (2009). Relationship between
the hip and low back pain in athletes who participate in rotation-related sports. Journal
of sport rehabilitation, 18(1), 60.
36. McGill, S. M., & Cholewicki, J. (2001). Biomechanical basis for stability: an
explanation to enhance clinical utility. Journal of Orthopaedic & Sports Physical
Therapy, 31(2), 96-100.
37. Duchateau, J., & Hainaut, K. (1984). Isometric or dynamic training: differential effects
on mechanical properties of a human muscle. Journal of applied physiology, 56(2),
296-301.
29
38. Kanehisa, H., & Miyashita, M. (1983). Specificity of velocity in strength
training. European journal of applied physiology and occupational physiology, 52(1),
104-106.
39. Kaneko, M. (1983). Training effect of different loads on the force-velocity relationship
and mechanical power output in human muscle. Scand. J. Sports Sci., 5, 50-55.
40. Hakkinen, K. (1981). Effect of combined concentric and eccentric strength training and
detraining on force-time, muscle fiber and metabolic characteristics of leg extensor
muscles. Scand. J. Sports Sci., 3, 50-58.
41. Häkkinen, K. (1989). Neuromuscular and hormonal adaptations during strength and
power training. A review. The Journal of sports medicine and physical fitness, 29(1),
9-26.
42. Schmidtbleicher, D. (1992). Training for power events. Strength and power in sport, 1,
381-395.
43. Prue, P., McGuigan, M. R., & Newton, R. U. (2010). Influence of strength on
magnitude and mechanisms of adaptation to power training. Med. Sci. Sports
Exerc, 42, 1566-1581.
44. Ruben, R. M., Molinari, M. A., Bibbee, C. A., Childress, M. A., Harman, M. S., Reed,
K. P., & Haff, G. G. (2010). The acute effects of an ascending squat protocol on
performance during horizontal plyometric jumps. The Journal of Strength &
Conditioning Research, 24(2), 358-369.
45. Cheraghi, M., Agha Alinejad, H., Arshi, A. R., & Shirzad, E. (2014). Kinematics of
straight right punch in boxing. Annals of Applied Sport Science, 2(2), 39-50.
46. Aagaard, P., Simonsen, E. B., Andersen, J. L., Magnusson, P., & Dyhre-Poulsen, P.
(2002). Increased rate of force development and neural drive of human skeletal muscle
following resistance training. Journal of applied physiology, 93(4), 1318-1326.
47. Sukop, J., & Nelson, R. (1974). Effect of isometric training on the force-time
characteristics contraction.
30
48. Thorstensson, A., Grimby, G., & Karlsson, J. (1976). Force-velocity relations and fiber
composition in human knee extensor muscles. Journal of applied physiology, 40(1),
12-16.
49. Piorkowski, B. A., Lees, A., & Barton, G. J. (2011). Single maximal versus
combination punch kinematics. Sports Biomechanics, 10(01), 1-11.
50. Murphy, A. J., Wilson, G. J., & Pryor, J. F. (1994). Use of the iso-inertial force mass
relationship in the prediction of dynamic human performance. European journal of
applied physiology and occupational physiology, 69(3), 250-257.
51. McGuigan, M. (2017). Developing power. Human Kinetics.
52. Behm, D. G., & Sale, D. G. (1993). Intended rather than actual movement velocity
determines velocity-specific training response. Journal of Applied Physiology, 74(1),
359-368.
53. Kirby, T. J., Erickson, T., & McBride, J. M. (2010). Model for progression of strength,
power, and speed training. Strength & Conditioning Journal, 32(5), 86-90.
54. Garhammer, J. O. H. N. (1980). Power production by Olympic weightlifters. Medicine
and science in sports and exercise, 12(1), 54-60.
55. Garhammer, J., & Gregor, R. (1992). Propulsion forces as a function of intensity for
weightlifting and vertical jumping. J Appl Sport Sci Res, 6(3), 129-34.
56. Kraemer, William & Newton, Robert. (1994). Training for improved vertical jump.
Sports Science Exchange. 7. 1-12.
57. Takano, B. (1992). RESISTANCE EXERCISE: The power clean—perspectives and
preparation. Strength & Conditioning Journal, 14(1), 68-71.
58. Berger, R. A. (1963). Effects of dynamic and static training on vertical jumping
ability. Research Quarterly. American Association for Health, Physical Education and
Recreation, 34(4), 419-424.
31
59. Wilson, G. J., Newton, R. U., Murphy, A. J., & Humphries, B. J. (1993). The optimal
training load for the development of dynamic athletic performance. Medicine and
science in sports and exercise, 25(11), 1279-1286.
60. Young, W. B., & Bilby, G. E. (1993). The effect of voluntary effort to influence speed
of contraction on strength, muscular power, and hypertrophy development. The Journal
of Strength & Conditioning Research, 7(3), 172-178.
61. Newton, R. U., & Wilson, G. J. (1994). The kinetics and kinematics of powerful upper
body movements: The effect of load. Journal of Biomechanics, 27(6), 645.
62. Urbin, M. A., Fleisig, G. S., Abebe, A., & Andrews, J. R. (2013). Associations between
timing in the baseball pitch and shoulder kinetics, elbow kinetics, and ball speed. The
American journal of sports medicine, 41(2), 336-342.
63. Roberts, T. J. (2002). The integrated function of muscles and tendons during
locomotion. Comparative Biochemistry and Physiology Part A: Molecular &
Integrative Physiology, 133(4), 1087-1099.
64. Alexander, R. M., & Bennet-Clark, H. C. (1977). Storage of elastic strain energy in
muscle and other tissues. Nature, 265(5590), 114-117.
65. Chmielewski, T. L., Myer, G. D., Kauffman, D., & Tillman, S. M. (2006). Plyometric
exercise in the rehabilitation of athletes: physiological responses and clinical
application. Journal of Orthopaedic & Sports Physical Therapy, 36(5), 308-319.
66. Poliquin, C., & Patterson, P. (1989). Terminology: Classification of strength
qualities. Strength & Conditioning Journal, 11(6), 48-52.
67. Rassier, D. E., & Herzog, W. (2005). Force enhancement and relaxation rates after
stretch of activated muscle fibres. Proceedings of the Royal Society B: Biological
Sciences, 272(1562), 475-480.
68. Bosco, C., & Komi, P. V. (1979). Mechanical characteristics and fiber composition of
human leg extensor muscles. European journal of applied physiology and occupational
physiology, 41(4), 275-284.
32
69. Bosco, C., & Komi, P. V. (1979). Mechanical characteristics and fiber composition of
human leg extensor muscles. European journal of applied physiology and occupational
physiology, 41(4), 275-284.
70. Krause, J. (1986). Biomechanics: A qualitative approach for studying human
movement.
71. Neto, O. P., Pacheco, M. T. T., Bolander, R., & Bir, C. (2009). Force, reaction time,
and precision of Kung Fu strikes. Perceptual and motor skills, 109(1), 295-303.
72. Jiang, C. H., Ranganathan, V. K., Siemionow, V., & Yue, G. H. (2017). The level of
effort, rather than muscle exercise intensity determines strength gain following a six-
week training. Life sciences, 178, 30-34.
73. Bompa, T., & Buzzichelli, C. (2015). Periodization training for sports, 3e. Human
kinetics.
74. Schmidtbleicher, D. (1985). Strength training: part 2: structural analysis of motor
strength qualities and its application to training. Science Periodical on Research and
Technology in Sport, 5, 1-10.
75. Taber, C., Bellon, C., Abbott, H., & Bingham, G. E. (2016). Roles of maximal strength
and rate of force development in maximizing muscular power. Strength &
Conditioning Journal, 38(1), 71-78.
76. Hodgson, M., Docherty, D., & Robbins, D. (2005). Post-activation potentiation. Sports
medicine, 35(7), 585-595.
77. Rhea, M. R., Alvar, B. A., Burkett, L. N., & Ball, S. D. (2003). A meta-analysis to
determine the dose response for strength development. Medicine and science in sports
and exercise, 35(3), 456-464.
78. Hakkinen, K. (1985). Changes in electrical and mechanical behavior of leg extensor
muscles during heavy resistance strength training. Scand J Sports Sci, 7, 55-64.
79. Häkkukinen, K., Komi, P. V., & Alen, M. (1985). Effect of explosive type strength
training on isometric force‐and relaxation‐time, electromyographic and muscle fibre
33
characteristics of leg extensor muscles. Acta Physiologica Scandinavica, 125(4), 587-
600.