ArticlePDF AvailableLiterature Review

An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands, Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game

Authors:

Abstract

Whilst there are various avenues for performance improvement within collegiate American football (AF), there is no comprehensive evaluation of the collective array of resources around performance, physical conditioning and injury and training/game characteristics to guide future research and inform practitioners. Accordingly, the aim of the present review was to provide a current examination of these areas within collegiate AF. Recent studies show that there is a wide range of body compositions and strength characteristics between players, which appear to be influenced by playing position, level of play, training history/programming and time of season. Collectively, game demands may require a combination of upper and lower body strength and power production, rapid acceleration (positive and negative), change of direction, high-running speed, high intensity and repetitive collisions and muscular strength endurance. These may be affected by the timing of, and between, plays and/or coaching style. AF players appear to possess limited nutrition and hydration practices, which may be disadvantageous to performance. AF injuries appear due to a multitude of factors: strength, movement quality, and previous injury whilst there is also potential for extrinsic factors such as playing surface type, travel, time of season, playing position and training load. Future proof of concept studies are required to determine the quantification of game demands with regards to game style, type of opposition and key performance indicators. Moreover, more research is required to understand the efficacy of recovery and nutrition interventions. Finally, the assessment of the relationship between external/internal load constructs and injury risk is warranted.
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
Note. This article will be published in a forthcoming issue of the
International Journal of Sports Physiology and Performance. The
article appears here in its accepted, peer-reviewed form, as it was
provided by the submitting author. It has not been copyedited,
proofread, or formatted by the publisher.
Section: Brief Report
Article Title: An Updated Review of the Applied Physiology of American Collegiate
Football: The Physical Demands, Strength/Conditioning, Nutritional Considerations and
Injury Characteristics of America’s Favourite Game
Authors: Hugh H.K. Fullagar1,2, Robert McCunn3, and Andrew Murray1
Affiliations: 1Department of Athletics (Football), University of Oregon, Eugene, OR, USA.
2Sport & Exercise Discipline Group, UTS: Health, University of Technology, Australia.
3Institute of Sport and Preventive Medicine, Saarland University, Saarbrücken, Germany.
Journal: International Journal of Sports Physiology and Performance
Acceptance Date: March 7, 2017
©2017 Human Kinetics, Inc.
DOI: https://doi.org/10.1123/ijspp.2016-0783
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
Title: An updated review of the applied physiology of American
collegiate football: The physical demands,
strength/conditioning, nutritional considerations and injury
characteristics of America’s favourite game
Submission Type: Brief Review
Authors: Hugh H.K. Fullagar1,2
Robert McCunn3
Andrew Murray1
Institutions: 1Department of Athletics (Football), University of Oregon, Leo
Harris Pwky Drive, Eugene, OR, USA
2Sport & Exercise Discipline Group, UTS: Health, University
of Technology, Australia
3Institute of Sport and Preventive Medicine, Saarland
University, Saarbrücken, Germany
Corresponding author Hugh Fullagar
Department of Athletics (Football)
University of Oregon
Eugene, OR
United States of America
Email: hughf@uoregon.edu
Running head: An updated review on the applied physiology of American
Football
Abstract word count: 250
Text only word count: 5127
Number of Tables: 0
Number of Figures: 0
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
ABSTRACT
Whilst there are various avenues for performance improvement within collegiate American
football (AF), there is no comprehensive evaluation of the collective array of resources around
performance, physical conditioning and injury and training/game characteristics to guide future
research and inform practitioners. Accordingly, the aim of the present review was to provide a
current examination of these areas within collegiate AF. Recent studies show that there is a
wide range of body compositions and strength characteristics between players, which appear
to be influenced by playing position, level of play, training history/programming and time of
season. Collectively, game demands may require a combination of upper and lower body
strength and power production, rapid acceleration (positive and negative), change of direction,
high-running speed, high intensity and repetitive collisions and muscular strength endurance.
These may be affected by the timing of, and between, plays and/or coaching style. AF players
appear to possess limited nutrition and hydration practices, which may be disadvantageous to
performance. AF injuries appear due to a multitude of factors: strength, movement quality, and
previous injury whilst there is also potential for extrinsic factors such as playing surface type,
travel, time of season, playing position and training load. Future proof of concept studies are
required to determine the quantification of game demands with regards to game style, type of
opposition and key performance indicators. Moreover, more research is required to understand
the efficacy of recovery and nutrition interventions. Finally, the assessment of the relationship
between external/internal load constructs and injury risk is warranted.
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
1 Conceptual introduction
American Football (AF) is one of the most popular and wealthiest sports in the world1.
Extensive resources are dedicated to the sport at the collegiate level (National Collegiate
Athletics Association; NCAA) where the sport is considered a mainstay of American culture1,2.
In addition, collegiate AF is now broadcast and played in other countries, expanding its global
brand and giving it a wider exposure than in previous years. Scientific studies on collegiate AF
have grown exponentially since the first paper in 1969, leading to various avenues of scientific
development in key areas from this time to the present day. These include injury prevention3,4,
concussion5, return to play injury characteristics6,7, analysis of strength and conditioning8-11,
overall health12 and wellbeing and most recently the objective quantification of training and
games13-15.
Despite the popularity, social impact and economic investment in collegiate AF, there
are few collective peer-reviewed resources which assess the wide scope of AF and guide
scientific support for staff, coaches and practitioners within the sport. Indeed, whilst previous
reviews have explained the basic rules and physiological demands of the sport16,17, there
remains no comprehensive evaluation of the collective array of performance, physical
conditioning, injury and training/game characteristics. This is surprising given the high injury
rates (36 per 1000 athlete exposures18) in collegiate AF and the negatively associated monetary
cost, performance outcomes and overall student-athlete health and welfare1.
Given both the economic and scientific growth of AF since previous reviews, there is a
clear need for a comprehensive updated evaluation of the applied physiology of collegiate AF
to guide future research and inform practice. Therefore, the aims of this critical review were
focused on evaluating the demands of training and games, the differing components of physical
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
conditioning, an analysis of nutritional considerations and requirements, and injury
characteristics of collegiate AF.
2. Description of American collegiate football
There are three divisions in NCAA football, with Division I also having two divisions
(the upper FBS; football bowl and the lower FCS; football championship). During a typical
regular season, players in the highest NCAA level (Division I; DI) participate in 12 games on
a consecutive weekly basis. The biggest differences between the collegiate and professional
games are that collegiate athletes are not paid a large salary (rather scholarship and stipend
allowances), they are involved in full-time education and are subject to NCAA compliance
laws. Collegiate AF is also unique from the professional version of the game in that players
cannot be bought and sold with a limit on the number of scholarships per university (85 at FBS
level, 63 at FCS level). Student-athletes are recruited from high school based on their athletic
ability, strength testing, high school highlights, cognitive ability and personality. It is well
established that getting the best talent is paramount for success19. Indeed, a 5-star or ‘blue-chip’
recruit may mean $150K in Championship income to his chosen school19 as they can bring
0.44 more wins than a 4-star recruit. This effect may last for five years upon initial recruitment20
(i.e. the maximum duration of their time at the university).
Since the most recent review on AF16, the basic principles of the game have not
changed. The game is still played over four 15 minute quarters by 11 players on the field for
each team. These players come from a squad of 70-120 depending on if the game is at home or
away, and interchange freely. Players specialize in positions and as such their specific
responsibilities shape the demands and training styles of the sport. These are examined more
closely in section 3.2 but comprise of defensive (defensive backs, DB; linebackers, LB;
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
defensive line, DL), offensive (quarterbacks, QB; offensive line, OL; wide receivers, WR; tight
ends, TE; running backs, RB) and special teams (ST; kickers, punters and long snappers).
3. Physiology overview of D1 American Football
3.1 Mass, stature, body composition and muscle function of players
Stature and body size is considered a major contributor to performance in AF21. The
trend has been for mass to increase longitudinally over time with associated improvements in
strength, power and speed22. In DI players body fat measures typically range from 9-24%
across positions with a mass in the range of 88 137 kg when they enter training camp at the
beginning of preseason23,24. OL and DL have been shown to possess ~9% greater fat mass than
the skilled positions, possibly increasing susceptibility to health risks due to their size25. While
this may be a health concern after their football careers it can also be a problem during. These
positions typically exhibit a number of at risk criteria for obesity25 which in turn contributes to
the ability to dissipate heat which is compromised by their relatively static training regime26,27.
Body fat levels vary significantly across positions, with DB’s, RB’s and WR’s being
the leanest and the OL and DL having the most17,24,25. The methods to assess though have also
differed across studies with no definitive measure prevailing. It would seem pertinent to follow
the skinfold measurement guidelines recommended by the International Society for the
Advancement of Kinanthropometry (ISAK) or use direct measurement via Dual-energy X-ray
absorptiometry (DXA) to ensure accuracy and reliability of these measures.
Across a season it has been shown at a team level that there are reductions in lean mass
and increases in percentage body fat as measured by DXA28. There is typically no significant
relationship between body composition and playing year29 or physical performance30. The body
composition related to differing football positions may place individuals at an increased risk
for cardiovascular disease with higher fasting glucose, lower HDL, increased blood pressure
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
and thicker arteries12. Another study has shown that 80% of football athletes have at least 1
abnormal resting ECG finding with the majority being left ventricular hypertrophy31 these
findings tended not to be replicated during maximal exercise stress tests but raise questions
about the strain of maintaining a football physique for certain positions (i.e. those that typically
have a high body fat %). However, although high body fat may be present in some positions,
there is evidence to show that linemen do become leaner after their first year of collegiate
football22.
3.2 The physiological demands of AF
AF can be characterized as an acyclic sport with many functions being continuously
performed. For example, a DB may backpedal, cut, accelerate and tackle an opponent in one
given play. Thus, players need to have a combination of physical qualities to be able to cope
with the intense collisions and high-intensity bouts of exercise that are short in duration but
frequent in number over a 60 min game of regular playing time (3-4 h in real time). These
repeated short (~5s per play32) but high intensity actions over the course of a prolonged period
suggest a combination of energy contributions from the phosphocreatine (PCr) energy system
and anaerobic glycolytic pathway17. Although variable (46.9 ± 34 seconds32), the different
styles of offenses/plays and injury-, tactical- and advertising-derived time-outs, result in typical
recovery time between plays being ~25-40 s. However, specific repeated plays with short
periods of rest (i.e. ‘up-tempo’ football) may also place an additional demand on the aerobic
system. This may be concerning given the cardiovascular endurance of football players is
historically not well developed33. Unfortunately, there is no research to the authors’ knowledge
which has investigated the physiological response (e.g. cardiovascular changes) of players
during an actual football game (though limited simulations have occurred34) making it
difficult to infer the exact physiological requirements required to perform AF.
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
3.2.1 Quantification and effect of game-related AF activity
Although the use of global positioning systems (GPS) and built in inertial measurement
units (IMU) to quantify external training and match load is becoming commonplace in AF
(personal communication), there are presently limited studies which have quantified the
physical demands of AF game-play. Wellman and colleagues14 monitored 33 DI players during
12 regular season games. The authors found significant differences between offensive and
defensive positional groups, with WR’s and DB’s completing significantly greater total
distance, high-intensity running, sprint distance, and high-intensity acceleration (positive and
negative) efforts than other positions. These total distances reached ranges of 3013-5530 m
(655 m of high intensity running), with the high intensity portion (5-20%) made up of ~10
sprints and ~100 accelerations (both positive and negative) depending on position14. The
differences in high intensity work are consistent with pre-season periods where non-linemen
cover more high intensity distance than linemen35. Wellman and colleagues13 also separately
analysed the intensity, number and distribution of impact forces experienced by players during
competition using integrated accelerometry. Within the offensive groups, WR’s sustained more
5-6.5 G force impacts (moderate to light) than other position groups, whereas RB’s were found
to endure the most severe (>10 G force) impacts bar the QB’s. DB’s and LB’s absorbed more
very light (5.0-6.0 G force) impacts, and defensive tackles (interior DL) reported significantly
more heavy and very heavy (7.1-10 G force) impacts than other defensive positions13. These
studies further our understanding of the demands imposed on players, which may form the
basis for the design of position-specific monitoring and training in the preparation for the
external load and impact forces performed in games. For instance, since RB’s endure the most
severe impacts in games within skill positions, practitioners must balance the need for ensuring
these players are sufficiently recovered from each game whilst also ensuring they are
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
adequately prepared to cope with these in-game impacts. In this example, RB’s may benefit
from off-season conditioning which focuses on the development of physical attributes (e.g.
upper body muscular adaptation) which enhance their resilience to absorb these impact forces.
In addition to GPS and IMU, some studies have also attempted to evaluate the average
duration of play, rest intervals and series within games to guide practitioners in developing
appropriate conditioning programs for their teams. Iosia and Bishop32 reported that the average
duration of a play was 5.23 ± 1.7 s, with significant differences apparent between run plays
(4.86 ± 1.4 s) and pass plays (5.60 ± 1.7 s). The average duration of rest between plays without
extended rest (time outs and injury attention) was 36.1 ± 6.7 s with the average rest time
between series was 11:39 ± 4:19 min. These results should be treated with caution though, as
they were analysed on only two teams over ten years ago32. Given the difference in game styles
across teams, divisions and professional levels, along with the development of various offenses
in the last decade, especially at the collegiate level (e.g. ‘spread, up-tempo, ‘air raid’),
practitioners are encouraged to conduct ‘in-house research’ to determine the average duration
and rest intervals of their playbook to develop appropriate training and conditioning programs.
Indeed, this preparation is critical since it can determine adequate player preparation with
regard to both performance and injury resilience11. Although the evidence is limited, it is
generally assumed that in-game demands incur greater impact collisions and pose greater injury
risk than training15. For example, Wilkerson and colleagues15 retrospectively analysed inertial
measurement and injury training and game data for 45 DI players, with both the coefficient of
variation for average inertial load and increased exposure to game conditions found to be
strongly associated with injury occurrence = 9.048; p = 0.004; odds ratio = 8.04; 90% CI:
2.39, 27.03). It has also been shown that line players experience significantly higher cumulative
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
linear acceleration forces (a combination of impacts of player on player and player on ground)
when compared to skill positions in both practices and games36.
Despite this recent growth in the quantification of training and game-related activity in
AF, there remains several gaps in the current literature. The objective quantification of game
and training demands with regards to game style, time of the season (acute vs chronic), type of
opposition and performance success (e.g. winning/losing, key performance indicators) remains
unknown. Furthermore, our understanding of the relationship between the various external
load constructs (e.g. total distance, high intensity running, speed, accelerations, impacts) and
other markers of load (e.g. s-RPE-TL, markers of wellness) within AF is limited. Perhaps most
pertinently, despite the growth in literature in other football codes which assess the complex
relationship between training/game loads and injury risk, there is a dearth of such evaluations
in AF.
3.2.2 Recovery and fatigue markers in response to games
The effect of the aforementioned loading demands during games can cause short term
reductions in power and peak force, muscle damage (creatine kinase; CK) and an increase in
cortisol37. A longitudinal examination of biochemical markers in DIII players showed that the
most stressful time in the season is typically (pre-season) training camp as this was associated
with the largest increase in markers of muscle damage38. The suggestion is that this intense
period of training creates a buffer for adaptation for the repeated trauma of the season. Indeed,
once games are played in the competitive season, players are reported to incur "contact
adaptation", indicating that players may build up a response to the repeated contacts and
muscular trauma induced throughout the season39. For instance, Kraemer and colleagues40
showed that changes in CK and adrenal cortical stress over a typical DI season are minimal,
although large individual variations can be observed40. Practitioners should also be aware that
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
players can possess above normal resting soft tissue damage levels going into games, indicating
that recovery should be carefully monitored throughout the training week39. Indeed, it has
recently been shown that perceptions of wellness (soreness, sleep, energy) can take longer than
4 days to return to pre-game levels in DI players41 and thus should be considered when
prescribing training and/or recovery during an in-season week.
Consideration should also be given to the travel induced in a typical season. For
instance, cross-country (westward) air travel across the United States (~6 h; three time zones)
followed by simulated sporting competition and a return flight home has been shown to worsen
measures of jet lag, sleep quality, hormonal responses (epinephrine, testosterone, and cortisol),
muscle tissue damage markers (CK), and physical performance (countermovement jump, pro-
agility drill and 40-yd sprint)42. Interestingly, within this study, a control group whom wore
compression garments were shown to result in no reductions in any parameters of physical
performance42. Although outside the scope of this review, there are various recovery methods
which may benefit the return of exercise or psychological performance following training or
games (e.g. sleep, nutrition, cold-water immersion, compression, active recovery). However, it
should be noted that there is a scarcity of research of the effectiveness of these methods
(individual or combined) for AF players. At present it would appear most beneficial to target
recovery practises at specific individuals based on the demands or load response of their
position and/or the individual’s preference.
4. Components of AF training
The majority of research within AF is directed towards the importance of optimising
physical training and performance outcomes. Specifically, there is a widely acknowledged
importance for the development of strength, power, speed and conditioning for AF players to
be both successful and resilient to injury throughout the course of a season and their careers11.
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
Indeed, since the physical demands of the sport place a wide variety of stressors on players’
bodies16, it is pertinent that various physical attributes are developed in order to enhance
performance and be resilient to injury. This importance has led to an increased significance
bestowed upon strength and conditioning coaches, whose primary role is to improve the
physical performance of their players. Indeed, such focused significance may explain the
improvement in various physical parameters in more recent players compared to those in
previous decades (e.g. RBs in 2000 had higher scores in bench press, power, and vertical jump
by 11, 9, and 7.7%, respectively than those in 198743). Furthermore, programs display
improved strength and power performance (e.g. significant increases in strength [~30%
improvement in the 1RM bench press and ~35% increase in squat strength]10) during the course
of an athlete’s career. With this in mind, the following section briefly examines the various
components of AF training and programming.
4.1. Strength and conditioning training programs
Strength and conditioning within AF is historically classified as developing and
improving the individual player for specific physical characteristics or testable goals of the
program (rather than wins vs losses11). This physical development is directed by the day-to-
day exercise prescription of choice and order of exercises, number of sets, level of intensity
and length of rest periods11. Typically, a balanced strength and conditioning program entails a
variety of strength/power training, aerobic and anaerobic conditioning, speed (linear and
multidirectional) development and muscular strength endurance both within the weight room
and on the training field. The development of physical performance characteristics in AF
primarily take place in the off-season period, where the majority of gains in upper and lower
body exercises occur. However, there is no clear indication to which is the most efficacious
periodization strategy within this period (e.g. non-periodised versus traditional linear
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
periodisation or non-linear periodised training44). It has been suggested that the efficacy of the
offseason training program is dependent on the length of both the program itself and the period
of rest/recovery prior44. Comparatively, physical performance enhancement in the in-season
period is likely limited by accumulated fatigue from playing time thus a focus is directed
towards strength and power maintenance during this period16. However, there are studies which
report 1RM squat improvements in DIII players during the regular season9, with improvements
suggested to most likely occur under with a linear design in-season weight training program45.
In-season improvements for higher division and professional players would appear more
difficult to attain, as these players are physically more advanced in terms of strength, power,
speed and agility46. Indeed, this re-emphasises the importance of physical performance
development prior to the season (and over subsequent off-seasons) since these characteristics
(power, speed and agility) have been shown to favour players whom are both drafted as
professionals over those who are not47 and order of draft status48.
Stodden and Galitski49 investigated the longitudinal effects of a strength and
conditioning program over four years of consecutive training in 84 DI players. These authors
found that certain performance data (% body fat, vertical jump) saw the greatest significant
improvements in the first year of eligibility, whilst others also made further improvements into
the second year (agility, lean body mass, power index from the vertical jump). Of the
performance data only bench press significantly improved throughout the 4 y of training across
all subjects, showing that the greatest number of improvements for the majority of parameters
may only occur in the initial years of the training program. In contrast, Hoffman and
colleagues10 found significant improvement in the 1RM bench press, vertical jump and squat
strength but not speed or agility over DIII player’s careers. These findings would suggest that
whilst strength and power improvements are attainable over a player’s career, speed and agility
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
may be more difficult. It also has been suggested that to elicit further strength gains in
previously trained football players there needs to be an increase in work volume11.
When viewed collectively, it should be noted that strength, power and speed training
can typically vary dependant on the offensive/defensive scheme and coaching style. For
instance, even when performing sets to failure (e.g. 10-RM), multiple sets are possible if
sufficient rest is allowed11. This may help build force production with less rest, a characteristic
which can contribute to success in a no-huddle (i.e. up-tempo) offensive scheme. Furthermore,
an up-tempo coaching scheme may require faster, more agile players and thus speed (linear
and multidirectional) development may be a focus for that team’s training program50. Indeed,
speed has been shown to distinguish between players’ draft status and playing ability47,48.
Comparatively, a slower ‘pro style’ offense, where rest in between plays is maximised, may
inherently produce stronger and larger players designed for more run-block plays. From a
defensive standpoint, if the defense has to remain on the field for sustained periods due to the
types of offenses faced, then they may benefit from multiple circuit style programs which
develop local muscular endurance11. It is also important to note that improvements in training
programs are dependent on the intensity of training and the amount of resistance training
players do prior to entering the collegiate setting (i.e. the athletes training age). Some authors
suggest that during traditional strength training the greatest strength improvements are attained
when training intensity exceeds 80% of players’ 1RM9,16. Comparatively, other authors favour
Olympic lifting (where loads can range from 65-90%) over traditional power lifting51,52 , where
significantly greater improvements have been reported in 1RM squat, 40-yd sprint time and
vertical jump performance8. Overall, it would appear a balanced approach using a range of
loads depending on how strength and power is demonstrated during football training and games
would be the most beneficial.
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
The training program can also vary dependant on the physical needs of each playing
position. For instance, an offensive linemen’s primary role is defending the line of scrimmage
to either protect the quarterback trying to complete a throw or aid a running back as they run
the ball, which involves contesting defensive lineman who weigh up to 150 kg43. Thus, a focus
for this position may include a greater reliance on upper body isometric strength and lower
body power (higher squat and bench press scores43; higher body fat %24). In contrast, wide
receivers must possess the ability to cover large distances at maximal speed, whilst also
performing blocking sequences. Thus, these personnel are expected to produce repeated high
levels of lower limb power, endurance and acceleration whilst also possessing strong relative
isometric strength (lower 40-yd dash times and higher squat/% of body weight than lineman43).
Following on from this speed requirement, a perhaps commonly overlooked aspect of AF
training is the development of linear and multidirectional speed. Indeed, this is considered an
important aspect of any football training program50. Eight weeks of in-season training has been
shown to improve speed in D1 red-shirt (defined as training and practicing with the team but
not playing in games) AF players53 with similar findings reported in long-term training studies
in other sports (e.g. rugby union; 2 years54). However, whilst speed development appears a
critical part of playing AF (especially considering the demands of the game; see section 3), the
peer-reviewed research reporting the details and effects of such approaches is limited in AF.
Taken collectively, future research is required to determine the effect of the variety of
training programs available, psychological factors and other factors (e.g. environmental,
genetics) on physical development in AF. More research which investigates the relationship
between physical performance and on-field assessments (e.g. the positive association between
1-RM squat and power clean in linemen with on-field velocity in a particular skill55) are also
required. Furthermore, whilst appreciating the difficulty of isolating causal effects in field-
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
based athletic performance investigations, the analysis of the relationships between these
characteristics and measure of success and/or AF-specific key performance indicators is
warranted. Indeed, such analysis would presumably aid recruiting and assist in optimising the
physical development and training of individual players.
5. Nutrition requirements and considerations for AF
Sports nutrition is a critical component of any training program; however, is often
overlooked by student-athletes. For instance, it has been shown that DI athletes have inadequate
sports nutrition knowledge56. Football players specifically also need education on sport
nutrition57. Players have been reported to eat out on average 23% of the time and of those meals
eat ‘fast food’ more than 50% of the time57. On entry to college, athletes are challenged by a
number of factors including practice schedules and class time58 which can result in inadequate
energy intake when matched for activity level (i.e. training59). The energy requirements across
positions are estimated to be from 5200-6500 kilocalories daily depending on size and stature60
Convenience and cost of food have been shown to be the major determinants of what
athletes will eat61 and some athletes are aware that they don’t have adequate consumption of
the major food groups62. Research should establish the actual metabolic requirements of
practice and games to allow tailored nutritional interventions at an individual level. Nutrition
staff must also comply with strict NCAA standards, with caffeine and creatine two examples
which are banned for distribution (but can be consumed). Furthermore, given the impact of
concussion there has been interest in supplements that can mitigate its affects. Omega-3 fatty
acids, curcumin and resveratrol have been shown to have protective effects5 and
supplementation of DHA may offset the number of concussions experienced63 and control the
inflammation from acute football exercise64.
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
Hydration is also critical to both health and performance especially when practices
can occur in padded equipment in extreme environments. Similar to nutrition, players appear
to lack basic knowledge about hydration. Judge and colleagues65 found that only a quarter of a
sample from two schools reported drinking enough fluids before, during and after a practice.
Godeck and colleagues66 showed in a DII programme where fluid was only available during
water breaks, that the sweat rate was the same as professional players on average (1.8 L/h) but
there was a higher sweat rate in linemen than backs (2.3 v 1.6 L/h). This deficit in linemen can
be exacerbated by starting the sessions hypo-hydrated especially given the static nature of their
training which can reduce the avenue for heat loss via convection27 while their increased mass
means a higher sweat rate26. Furthermore, there is a worrying trend of hyperhydrating
intravenously to prevent dehydration, heat illness and cramps67. While they may target the
high-risk individuals on the team this seems a preventable practice with better education of
football student-athletes and more regimented following of their hydration practices.
6. Injury patterns, risk factors and return to play within AF
Due to the inherently aggressive and intense physical demands of AF, injuries are a
well-acknowledged aspect of the sport. The consequences of player injury are multifaceted and
range in nature from financial and emotional to long-term health related. From collegiate
players’ perspective, injuries can ultimately have a negative impact on future earning potential
if they eventually progress to the NFL68 due in part to prior serious injury reducing the
likelihood of a player being drafted into the NFL69.
6.1 Epidemiology
Of concern is the high injury rate within college football (e.g. 36 per 1000 athlete
exposures18). Indeed, a summary of 15 NCAA supported sports over a 16-year observation
period revealed that AF displayed the highest injury rates of all the sports included (9.6 and
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
35.9 injuries per 1000 athlete exposures for training and games respectively)70. Perhaps the
most concerning aspect related to injury epidemiology within collegiate AF is that there
appears to be a trend of increasing lower extremity injury rates71.
6.1.1 Anterior cruciate ligament injuries (ACL)
ACL injury represents a season-ending injury within collegiate AF since the majority
of NCAA and NFL physicians recommend waiting at least six to nine months before returning
to play7. The incidence rate of ACL injuries during collegiate gameplay has been reported to
range between 8 and 10 per 10,000 athlete exposures and this represents a substantially higher
rate when compared with training (0.80 per 10,000 athlete exposures)3,72. Furthermore, AF
demonstrated the highest incidence rate of ACL injuries when compared to 14 other NCAA
supported sports and the average number of such injuries has displayed an increasing trend
since 200473. This alarming trend coupled with the already high incidence rate highlights that
ACL injury should be viewed as a priority when considering injury prevention measures within
collegiate AF. Neuromuscular and proprioceptive training should underpin ACL injury
prevention strategies since they have previously demonstrated efficacy in numerous studies4.
6.1.2 Head/concussion
As mentioned previously, AF-related concussion has received significant attention
within scientific research74. Indeed, this would appear justified considering the increase in
concussion incidence between 2010-2014 compared to 2006-200974. This increase in incidence
is likely due to a multitude of factors, including improved recognition and reporting of such
events74. A recent study within NCAA Division I football programs reported a concussion
incidence rate of 4.46 per 1000 athlete exposures during games74. Furthermore, over a quarter
of all players observed during the nine-year study period suffered at least one concussion74. It
should be noted that the consequences of suffering a concussion are not exclusive to the
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
head/trunk region; the odds of sustaining a lower extremity musculoskeletal injury after return
to play from a concussion are elevated75. As a contact sport, AF will likely always be associated
with a degree of risk for concussion; however, coaching tackling techniques that limit the
chances of sustaining direct blows to the head perhaps represent a strategy that may help reduce
incidence.
6.2 Factors affecting injury occurrence
Scientific research identifying risk factors for AF related injury is limited, especially
among collegiate players; however, some initial evidence exists. Proposed intrinsic injury risk
factors (relating to factors the player can influence) associated with AF include isokinetic
strength deficits and ratios76, movement quality77, previous injury and body mass index78.
Numerous extrinsic risk factors (external factors considered beyond the player’s control) have
also been investigated, including: environmental considerations such as ambient temperature
and altitude, playing surface type, travel time, time-zone change, stage of the season, playing
position and measures of training load15,79,80. Another contributor to injury risk unique to
student-athletes is academic stress. Mann et al.81 reported an almost two-fold greater likelihood
of injury among Division I collegiate football players during periods of high versus low
academic stress. The factors investigated so far almost certainly do not represent an exhaustive
list. Aerobic fitness, absolute strength, match load and playing experience (to name but a few)
constitute potential additional contributors to injury likelihood. Clearly, much further scope
exists to investigate potential injury risk factors within AF at the collegiate level.
6.3 Rehabilitation and return to play
Since financial investment into university athletic departments cannot be received
directly by players it is often funnelled toward support services in the form of training facilities,
medical support staff and equipment. However, safe return-to-play protocols pose an inherent
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
challenge to collegiate medical staff. Players and coaches have such a short competitive
window (i.e. 12 weeks of regular season games) to perform, it is inevitable that they may be
eager to return after injury before it is advisable to do so. In addition to restoring physical
qualities eroded by injury it is important that medical staff consider players’ psychological
readiness to return to play. This is particularly important in the case of players who may be so
determined to return to play prematurely that they put their long-term health in jeopardy6.
7 Conclusion
Collectively AF-physical demands may require a combination of upper and lower body
strength and power production, rapid acceleration (positive and negative), change of direction,
high running speed, high intensity and repetitive collisions and muscular strength endurance
which can be affected by numerous game factors. Given the breadth of variation in physical
demands, adequate training programs which allow players to cope with, and recover from,
these demands are paramount, especially given the high injury rates within AF cohorts. These
high incidences may be due to a multitude of factors such as strength, movement quality, and
previous injury whilst there is also potential for external considerations such as playing surface
type, travel time, stage of the season, playing position and training load. In addition, AF players
appear to possess limited nutrition and hydration practices, which may be disadvantageous to
performance. Indeed, more research is required to understand the efficacy of recovery and
nutrition interventions. Future proof of concept studies are required to determine the
quantification of game/training demands with regards to game style, type of opposition and
performance success (e.g. key performance indicators). The assessment of the relationship
between external and internal load constructs and injury risk would also appear warranted.
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
REFERENCES:
1. Klossner D, Corlette J, Agel J, Marshall S. Datadriven decision making in practice:
The NCAA injury surveillance system. New Directions for Institutional Research.
2009:53-63.
2. Heere B, James J. Sports Teams and Their Communities: Examining the Influence of
External Group Identities on Team Identity. Journal of Sport Management.
2007;21(3):319-337.
3. Dragoo J, Braun H, Durham J, Chen M, Harris A. Incidence and risk factors for injuries
to the anterior cruciate ligament in National Collegiate Athletic Association football:
data from the 2004-2005 through 2008-2009 National Collegiate Athletic Association
Injury Surveillance System. Am J Sports Med. 2012;40(5):990-995.
4. Donnell-Fink L, Klara K, Collins J, et al. Effectiveness of Knee Injury and Anterior
Cruciate Ligament Tear Prevention Programs: A Meta-Analysis. PLoS One.
2015;10(12).
5. Ashbaugh A, McGrew C. The Role of Nutritional Supplements in Sports Concussion
Treatment. Current Sports Medicine Reports. 2016;15(1):16-19.
6. Forsdyke D, Gledhill A, Ardern C. Psychological readiness to return to sport: three key
elements to help the practitioner decide whether the athlete is REALLY ready? Br J
Sports Med. 2016;(online first).
7. Erickson B, Harris J, Fillingham Y, et al. Anterior cruciate ligament reconstruction
practice patterns by NFL and NCAA football team physicians. Arthroscopy.
2014;30(6):731-738.
8. Hoffman J, Im J, Kang J, et al. The effect of a competitive collegiate football season on
power performance and muscle oxygen recovery kinetics. J Strength Cond Res.
2004;19:509-513.
9. Hoffman J, Kang J. Strength changes during an inseason resistance training program
for football. J Strength Cond Res. 2003;17:109-114.
10. Hoffman J, Ratamess N, Kang J. Performance changes during a college playing career
in NCAA division III football athletes. J Strength Cond Res. 2011;25:2351-2357.
11. Kraemer W. A series of studies - the physilogical basis for strength training in American
Football: fact over philosophy. Journal of Strength & Conditioning Research.
1997;11(3):131-142.
12. Feairheller D, Aichele K, Oakman J, et al. Vascular Health in American Football
Players: Cardiovascular Risk Increased in Division III Players. International Journal
of Vascular Medicine. 2016:1-6.
13. Wellman A, Coad S, Goulet G, Coffey V, McLellan C. Quantification of Accelerometer
Derived Impacts Associated With Competitive Games in NCAA Division I College
Football Players. J Strength Cond Res. 2016;[Epub ahead of print].
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
14. Wellman A, Coad S, Goulet G, McLellan C. Quantification of Competitive Game
Demands of NCAA Division I College Football Players Using Global Positioning
Systems. J Strength Cond Res. 2016;30(1):11-19.
15. Wilkerson G, Gupta A, Allen J, Keith C, Colston M. Utilization of Practice Session
Average Inertial Load to Quantify College Football Injury Risk. Journal of Strength &
Conditioning Research. 2016;30(9):2369-2374.
16. Hoffman J. The applied physiology of American football. Int J Sports Physiol Perform.
2008;3:387-392.
17. Pincivero D, Bompa T. A physiological review of American football. Sports Med.
1997;23(4):247-260.
18. Dick R, Ferrara M, Angel J, et al. Descriptive Epidemiology of Collegiate Men's
Football Injuries: National Collegiate Athletic Association Injury Surveillance System,
19881989 Through 20032004. J Athl Train. 2007;42(2):221233.
19. Bergman S, Logan T. The Effect of Recruit Quality on College Football Team
Performance. Journal of Sports Economics. 2016;17(6):578-600.
20. Langelett G. The Relationship between Recruiting and Team Performance in Division
1A College Football. Journal of Sports Economics. 2003;4(3):240-245.
21. Miller T, White E, Kinley K, Congleton J, Clark M. The effects of training history,
player position, and body composition on exercise performance in collegiate football
players. J Strength Cond Res. 2002;16(1):44-49.
22. Jacobson B, Conchola E, Glass R, Thompson B. Longitudinal Morphological and
Performance Profiles for American, NCAA Division I Football Players. J Strength
Cond Res. 2013;27(9):2347-2354.
23. Kaiser G, Womack J, Green J, Pollard B, Miller G, Crouse S. Morphological profiles
for first-year National Collegiate Athletic Association Division I football players. J
Strength Cond Res. 2008;22(1):243-249.
24. Melvin M, Smith-Ryan A, Wingfield H, Ryan E, Trexler E, Roelofs E. Muscle
Characteristics and Body Composition of NCAA Division I Football Players. J Strength
Cond Res. 2014;28(12):3320-3329.
25. Mathews E, Wagner D. Prevalence of Overweight and Obesity in Collegiate American
Football Players. Journal of American College Health. 2008;57(1):33-38.
26. Deren T, Coris E, Bain A, Walz S, Jay O. Sweating is greater in NCAA football linemen
independently of heat production. Med Sci Sports Exerc. 2012;44(2):244-252.
27. Deren T, Coris E, Casa D, et al. Maximum heat loss potential is lower in football
linemen during an NCAA summer training camp because of lower self-generated air
flow. Journal of Strength & Conditioning Research. 2014;28(6):1656-1663.
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
28. Binkley T, Daughters S, Weidauer L, Vukovich M. Changes in Body Composition in
Division I Football Players Over a Competitive Season and Recovery in Off-Season.
Journal of Strength & Conditioning Research. 2015;29(9):25032512.
29. Noel M, VanHeest J, Zaneteas P, Rodgers C. Body composition in Division I football
players. Journal of Strength & Conditioning Research. 2003;17(2):228-237.
30. Davis D, Barnette B, Kiger J, Mirasola J, Young S. Physical characteristics that predict
functional performance in Division I college football players. Journal of Strength and
Conditioning Research. 2004;18(1):115-120.
31. Crouse S, Meade T, Hansen B, Green J, Martin S. Electrocardiograms of Collegiate
Football Athletes. Clinical Cardiology. 2009;32(1):37-42.
32. Iosia M, Bishop P. Analysis of exercise-to-rest ratios during division IA televised
football competition. J Strength Cond Res. 2008;22:332340.
33. Wilmore J, Haskell W. Body composition and endurance capacity of professional
football players. Journal of Applied Physiology. 1972;33(5):564-567.
34. Hitchcock K, Millard-Stafford M, Phillips J, Snow T. Metabolic and thermoregulatory
responses to a simulated American football practice in the heat. J Strength Cond Res.
2007;21(3):710-717.
35. DeMartini J, Martschinske J, Casa D, et al. Physical demands of national collegiate
athletic association division I football players during preseason training in the heat. J
Strength Cond Res. 2011;25:2935-2943.
36. Grimes K, Shiflett E, Munkasy B, et al. Relationship Between Position, Cumulative
Impacts And Cumulative Accelerations In Ncaa Division I Football Players. Med Sci
Sports Exerc. 2016;48(5 Suppl 1):530-531.
37. Hoffman J, Maresh C, Newton R, et al. Performance, biochemical, and endocrine
changes during a competitive American football game. Med Sci Sports Exerc.
2002;34:1845-1853.
38. Hoffman J, Kang J, Ratamess N, Faigenbaum A. Biochemical and hormonal responses
during an intercollegiate football season. Med Sci Sports Exerc. 2005;37:1237-1241.
39. Kraemer W, Spiering B, Volek J, et al. Recovery from a national collegiate athletic
association division I football game: muscle damage and hormonal status. J Strength
Cond Res. 2009;23(1):2-10.
40. Kraemer W, Looney D, Martin G, et al. Changes in creatine kinase and cortisol in
National Collegiate Athletic Association Division I American football players during a
season. J Strength Cond Res. 2013;27(2):434-441.
41. Fullagar H, Govus A, Hanisch J, Murray A. The Time Course of Perceptual Recovery
Markers Following Match Play in Division I-A Collegiate American Footballers. Int J
Sports Physiol Perform. 2016;[Epub ahead of print].
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
42. Kraemer W, Hooper D, Kupchak B, et al. The effects of a roundtrip trans-American jet
travel on physiological stress, neuromuscular performance, and recovery. J Appl
Physiol. 2016;121(2):438-448.
43. Secora C, Latin R, Berg K, Noble J. Comparison of physical and performance
characteristics of NCAA division I football players: 1987 and 2000. J Strength Cond
Res. 2004;18(286-291).
44. Hoffman J, Ratamess N, Klatt M, et al. Comparison Between Different Off-Season
Resistance Training Programs in Division III American College Football Players. J
Strength Cond Res. 2009;23(1):11-19.
45. Hoffman J, Wendell M, Cooper J, Kang J. Comparison Between Linear and Nonlinear
In-Season Training Programs in Freshman Football Players. J Strength Cond Res.
2003;17(3):561-565.
46. Garstecki M, Latin R, Cuppett M. Comparison of selected physical fitness and
performance variables between NCAA division I and II football players. J Strength
Cond Res. 2004;18:292-297.
47. Sierer S, Battaglini C, Mihalik J, Shields E, Tomasini N. The National Football
League combine: Performance differences between drafted and nondrafted players
entering the 2004 and 2005 drafts. J Strength Cond Res. 2008;22(1):6-12.
48. McGee K, Burkett L. The National Football League combine: A reliable predictor of
draft status. J Strength Cond Res. 2003;17(1):6-11.
49. Stodden D, Galitski H. Longitudinal effects of a collegiate strength and conditioning
program in American football. J Strength Cond Res. 2010;24(9):2300-2308.
50. Ebben W, Blackard D. Strength and conditioning practices of National Football League
strength and conditioning coaches. J Strength Cond Res. 2001;15(1):48-58.
51. Cormie P, McBride J, McCaulley G. Validation of power measurement techniques in
dynamic lower body resistance exercises. J Appl Biomech. 2007;23(2):103-118.
52. Cormie P, McCaulley G, McBride J. Power versus strength-power jump squat training:
influence on the load-power relationship. Med Sci Sports Exerc. 2007;39(6):996-1003.
53. Kirwan R, Kordick L, McFarland S, Lancaster D, Clark K, Miles M. Dietary,
anthropometric, blood-lipid, and performance patterns of American College Football
Players during 8 weeks of training. Int J Sport Nutr Exerc Metab. 2012;22(6):444-451.
54. Barr M, Sheppard J, Gabbett T, Newton R. Long-term training-induced changes in
sprinting speed and sprint momentum in elite rugby union players. J Strength Cond
Res. 2014;28(10):2724-2731.
55. Jacobson B, Conchola E, Smith D, Akehi K, Glass R. Relationship Between Selected
Strength and Power Assessments to Peak and Average Velocity of the Drive Block in
Offensive Line Play. J Strength Cond Res. 2016;30(8):2202 2205.
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
56. Andrews A, Wojcik J, Boyd J, Bowers C. Sports Nutrition Knowledge among Mid-
Major Division I University Student-Athletes. 2016.
57. Jonnalagadda S, Rosenbloom C, Skinner R. Dietary practices, attitudes, and
physiological status of collegiate freshman football players. J Strength Cond Res.
2001;15(4):507-513.
58. Hinton P, Sanford T, Davidson M, Yakushko O, Beck N. Nutrient intakes and dietary
behaviors of male and female collegiate athletes. International Journal of Sport
Nutrition and Exercise Metabolism. 2004;14(4):389-405.
59. Cole C, Salvaterra G, Davis J, et al. Evaluation of Dietary Practices of National
Collegiate Athletic Association Division I Football Players. J Strength Cond Res.
2005;19(3):490.
60. Berning J. Fueling a football team. Sports Science Exchange. 2015;28(146):1-7.
61. Driskell J, Kim Y, Goebel K. Few Differences Found in the Typical Eating and Physical
Activity Habits of Lower-Level and Upper-Level University Students. Journal of the
American Dietetic Association. 2005;105(5):798-801.
62. Morse K, Driskell J. Observed sex differences in fast-food consumption and nutrition
self-assessments and beliefs of college students. Nutrition Research. 2009;29(3):173-
179.
63. Oliver J, Jones M, Kirk K, et al. Effect of docosahexaenoic acid on a biomarker of head
trauma in American Football. Med Sci Sports Exerc. 2016;48(6):974-982.
64. Capó X, Martorell M, Sureda A, Llompart I, Tur J, Pons A. Diet supplementation with
DHA-enriched food in football players during training season enhances the
mitochondrial antioxidant capabilities in blood mononuclear cells. European Journal
of Nutrition. 2015;54(1):35-49.
65. Judge L, Kumley R, Bellar D, et al. Hydration and Fluid Replacement Knowledge,
Attitudes, Barriers, and Behaviors of NCAA Division 1 American Football Players. J
Strength Cond Res. 2016.
66. Godek S, Bartolozzi A, Peduzzi C, et al. Fluid consumption and sweating in national
football league and collegiate football players with different access to fluids during
practice. Journal of Athletic Training. 2010;45(2):128-135.
67. Gesik N, Tan S, Prentiss G, Fitzsimmons S, Nichols A. The Use of Pregame
Hyperhydration With Intravenous Fluids in National Collegiate Athletic Association
Football Bowl Subdivision Teams. Clinical Journal of Sport Medicine.
2013;23(6):488-490.
68. Secrist E, Bhat S, Dodson C. The financial and professional impact of anterior cruciate
ligament injuries in National Football League Athletes. Orthop J Sports Med.
2016;4(8).
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
69. Brophy R, Lyman S, Chehab E, Barnes R, Rodeo S, Warren R. Predictive value of prior
injury on career in professional American football is affected by player position. Am J
Sports Med. 2009;37(4):768-775.
70. Hootman J, Dick R, Agel J. Epidemiology of collegiate injuries for 15 sports: summary
and recommendations for injury prevention initiatives. J Athl Train. 2007;42(2):311-
319.
71. Westermann R, Kerr Z, Wehr P, Amendola A. Increasing lower extremity injury rates
across the 2009-2010 to 2014-2015 seasons of National Colleagiate Athletic
Association football: an unintended consequence of the "targeting" rule used to prevent
concussions? Am J Sports Med. 2016;44(12):3230-3236.
72. Kerr Z, Simon J, Grooms D, Roos K, Cohen R, Dompier T. Epidemiology of Football
Injuries in the National Collegiate Athletic Association, 2004-2005 to 2008-2009.
Orthop J Sports Med. 2016;4(9).
73. Agel J, Rockwood T, Klossner D. Collegiate ACL Injury Rates Across 15 Sports:
National Collegiate Athletic Association Injury Surveillance System Data Update
(2004-2005 Through 2012-2013). Clin J Sport Med. 2016;26(6):518-523.
74. Houck Z, Asken B, Bauer R, Pothast J, Michaudet C, Clugston J. Epidemiology of
Sport-Related Concussion in an NCAA Division I Football Bowl Subdivision Sample.
Am J Sports Med. 2016;44(9):2269-2275.
75. Brooks M, Peterson K, Biese K, Sanfilippo J, Heiderscheit B, Bell D. Concussion
Increases Odds of Sustaining a Lower Extremity Musculoskeletal Injury After Return
to Play Among Collegiate Athletes. Am J Sports Med. 2016;44(3):742-747.
76. Zvijac J, Toriscelli T, Merrick S, Kiebzak G. Isokinetic concentric quadriceps and
hamstring strength variables from the NFL Scouting Combine are not predictive of
hamstring injury in first-year professional football players. Am J Sports Med.
2013;41(7):1511-1518.
77. Kiesel K, Butler R, Plisky P. Prediction of injury by limited and asymmetrical
Fundamental Movement Patterns in American football players. J Sport Rehabil.
2014;23(2):88-94.
78. Tyler T, McHugh M, Mirabella M, Mullaney M, Nicholas S. Risk factors for
noncontact ankle sprains in high school football players: the role of previous ankle
sprains and body mass index. Am J Sports Med. 2006;34(3):471-475.
79. Lawrence D, Comper P, Hutchison M. Influence of extrinsic risk factors on National
Football League injury rates. Orthop J Sports Med. 2016;4(3).
80. Mehran N, Photopoulos C, Narvy S, Romano R, Gamradt S, Tibone J. Epidemiology
of Operative Procedures in an NCAA Division I Football Team Over 10 Seasons.
Orthop J Sports Med. 2016;18(4).
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
An Updated Review of the Applied Physiology of American Collegiate Football: The Physical Demands,
Strength/Conditioning, Nutritional Considerations and Injury Characteristics of America’s Favourite Game
by Fullagar H HK, McCunn R, Murray A
International Journal of Sports Physiology and Performance
© 2017 Human Kinetics, Inc.
81. Mann J, Bryant K, Johnstone B, Ivey P, Sayers S. Effect of Physical and Academic
Stress on Illness and Injury in Division 1 College Football Players. J Strength Cond
Res. 2016;30(1):20-25.
Downloaded by Harcourt Hill Campus on 03/25/17, Volume 0, Article Number 0
... American football is a highly dynamic sport, where players execute various amounts of high-speed running, changes of direction, tackles, and collisions (10,22). Within football, positional roles are highly specific with distinct physical demands that influence individual and team performance (9). ...
... Those football activities are generally short in duration (;3-7 seconds) executing at, or close to, maximal intensity (9). To prepare for those high-intensity game demands, players typically participate in individual and team playbook drills to mimic the high-speed running and collision demands of American football during practice (10,11). ...
... In American football, coaches prescribe drills during practice sessions to focus on skill development or coordinated team play (8,24). Skill development is facilitated through individualized (indy) drills where players progress in deconstructed, positionspecific maneuvers believed to enhance the individual performance of players and position groups (10,22). Team playbook (team) drills and special team (ST) drills are anecdotally most representative of games, because they are devoted to situational and tactical planning of offensive, defensive, or ST gameplay (22)(23)(24). ...
Article
Full-text available
Quantifying player training loads allows football coaching staff to make informed adjustments to the volume and intensity of training. Physical workload intensity in American football practices have not been extensively quantified. The current study examined physical workload intensities across positions in American collegiate football during training. Data from player tracking technology (Catapult Vector) were collected from 72 American football players (National Collegiate Athletic Association Division I) during in-season practices. Players were involved in individualized skill (indy), team playbook (team), and special team (ST) drills during practice and analyzed for their specialist offensive or defensive role (e.g., linebacker or wide receiver). Player running (i.e., high-speed running and sprint) and accelerations (i.e., high-intensity PlayerLoad and high-intensity inertial movement analysis) per minute were of interest. Drill type and practice day had significant effects on all workload intensity metrics (p < 0.01), but not position. Greater running intensities were seen in ST drills compared with other drill types. Tuesday practice sessions had greater overall intensities compared with other days. Interaction effect of position and drill type was significant (p < 0.001) for all intensity metrics, indicating that position groups exhibited unique workload responses to the drill types. Drill type and practice day interaction effect was significant for all intensity metrics (p < 0.01). The findings may be informative for coaches to tailor physical workloads of practice drills for positional roles in preparation for games and practices. Player tracking technology can add value for strength and conditioning coaches to adjust training programs based on position-specific on-field demands of players.
... Based on the importance of speed in American football, this attribute is a primary focus of most strength and conditioning programs for this sport (7). However, several studies have shown that although strength increases for NCAA Division 1 football players over the course of their collegiate career, performance in the 40-yard sprint, proagility, and L-drill times tend to plateau (13,18). ...
... Similar to the studies cited above, we calculated momentum during the COD tests using average velocity scores. This computation can be considered appropriate for American football because the game is characterized by frequent multidirectional sprints that require a player to rapidly accelerate and decelerate over short distances (6,7). Therefore, the purpose of this investigation was to examine the momentum during the speed and COD tests commonly performed in the NFL combine testing battery. ...
Article
Speed, or the time to complete straight runs or agility drills, is commonly used to assess performance in collegiate American football players. However, it is common for players’ speeds to plateau by the second year of eligibility, whereas their body masses continue to increase. The purpose of this study was to track change in speed, body mass, and momentum (body mass · velocity), across Division 1 football players’ 4-year careers (n=512). Complete data were derived for the 40-yd sprint (n=82), the proagility shuttle (n=73), and the L drill (n=73) from the same NCAA Division 1 team over a 15-year period. Significant changes were seen for velocity between year 1 and the next 3 playing years (p < 0.05), with no differences between years 2 and 4, whereas body mass increased significantly across all playing years (p < 0.05). Further momentum increased across all years for all tests (p < 0.0001). These results indicate the importance of including changes in body mass when evaluating performances during sprints and change of direction drills. Our results also suggest that using sprint or agility drill times to evaluate playing potential across football players’ collegiate careers may be ineffective and can provide players with a false and disheartening picture of their improvements across their careers. Momentum, which incorporates training-induced increases in both speed and body mass, would be a more relevant and supportive measure of players’ improvements. In addition, the simple computation of this variable, using existing speed and body mass data, may be an important addition to the National Football League combine as a measure of playing potential in the professional game.
... In this study, the risk for FI was highest among football players. Nutritional requirements for football players are often higher than those for athletes in other sports, which may contribute to higher rates of FI among these student-athletes [24]. In addition, football is one of the largest teams on the campus in this survey. ...
Article
Full-text available
Background: Though the vulnerability of college students to food insecurity is well established, there is a paucity of studies focusing on the prevalence of food insecurity among student-athletes. Methods: A cross-sectional survey was conducted with collegiate athletes in the northwestern United States via an anonymous online survey. Food security status was assessed using the 10-item US Department of Agriculture Adult Food Security Survey. Results: Participating athletes (45/307, 14%) were primarily White, non-Hispanic (78%) females (73%) who lived and consumed meals off-campus (62% and 69%, respectively). Food insecurity was more prevalent among collegiate athletes than the general university population, 60% vs. 42%, respectively. Being a track or football athlete significantly predicted food security status (p = 0.002, p < 0.001, respectively). The risk for food insecurity was higher among collegiate football players (effect size, η2 = 0.86) compared with track athletes (effect size, η2 = 0.40). Conclusion: A statistically significant risk for food insecurity emerged among members of the football team. Factors contributing to disparate rates of food insecurity among college populations were explored and unique considerations for collegiate athletes discussed.
... In sports such as American football, most studies are directed toward optimizing physical preparation and performance (Fullagar et al. 2017). In a context where the goal of an athlete is to achieve excellence, it is essential to consider other factors that may influence the components of sport performance including psychological preparation and recovery (Battaglia et al. 2014;Schuster et al. 2018). ...
Article
Although nutrition influences performance, many athletes, including football players, do not meet nutritional requirements for their sport. The objective of this study was to determine the impact of a nutrition intervention combining nutrition education and cooking workshops on nutrition knowledge, intention, and perceived behavioral control in the preparation of healthy meals, dietary intakes, and diet quality in male university football players. Athletes ( n = 23; age: 22 ± 1 year) were randomly assigned to an intervention (2 h/week) ( n = 13) or control group ( n = 10) over three weeks. Questionnaires were completed before (pre), immediately after (post 1), and two months after the intervention (post 2). Dietary intakes and diet quality were evaluated from three web-based 24-h dietary recalls per visit. Mixed linear models for repeated measures with Tukey’s post hoc test were performed to determine the effects of the intervention on all outcomes. There was a group by time interaction for nutrition knowledge ( p = 0.002) that was higher immediately after and two months after the intervention compared to the control group. No differences on other outcomes were observed. Combining nutrition education and cooking workshops improved nutrition knowledge, but did not affect intention and perceived behavioral control in the preparation of healthy meals, dietary intakes, and diet quality in male university football athletes.
... Sports nutrition is an essential part of any training and competition program (12)(13)(14). The International Olympic Committee (IOC), the American College of Sports Medicine (ASCM) or the American Dietetic Association (ADA) among others (12,13) agree that optimum nutrition will help the athlete improve physical performance and recover faster after a workout or game. ...
Article
Full-text available
Introduction: only sparse scattered studies present a practical approach on the nutritional requirements of modern basketball players. Thispaper aims to gather and complete such a disseminated knowledge from a theoretical-practical perspective.Objectives: to analyze the fatigue produced during a basketball game, while offering a practical solution to accelerate its recovery through nutrition.Methods: database research over the reviews of the last 15 years and its original articles on basketball of the last 5 years.Results: the selection of nutrients and food supplements along with their proper timing and doses are key for a quicker and more effective recovery.Conclusions: nutrition before, during and after games or high intense practices, plays a fundamental role in the recovery of the basketball player (PDF) The role of nutrition in the recovery of a basketball player (English). Available from: https://www.researchgate.net/publication/360080845_The_role_of_nutrition_in_the_recovery_of_a_basketball_player_English [accessed May 17 2022].
... American Football is arguably the most popular sport within the United States of America and is continuing to gain popularity around the globe. Game demands in American Football require athletes to show proficiency in a variety of physical abilities such as upper and lower body strength and power production ability, rapid accelerations and decelerations, change of direction ability, high running speeds, and muscular endurance 1 . Athletic performance personnel in the sport of American Football routinely tests different parameters related to the previously mentioned key performance indicators (KPI). ...
Article
Full-text available
The identification of sport and position-specific key performance indicators has been of increased interest to practitioners working within high performance sport settings. The aim of this study was to create statistical models, across a spectrum of position groups, that explain the largest amount of variance in on-field performance over four collegiate American football seasons. A total of four position groups were analyzed, including Wide Receiver/ Tight End (n = 29), Running Backs (n = 8), Linebacker/ Defensive Line (n =41), Defensive Backs (n = 28). Different tests of physical performance (back squat, bench press, hang clean, 40-yard dash, pro-agility, L-drill, vertical jump, and broad jump) were set as the independent variables, while a Total Score of On-Field Performance, consisting of position-specific game statistics was set as the dependent variable. Linear mixed models, using backwards model selection were used to identify models that best fit the position-specific data. Results revealed that models consisted of at least three different physical performance tests, were position-specific, and explained the variance in on-field performance to different degrees. Significant correlations were found between physical performance models and on-field performance. Results from our study may be of interest to practitioners working within American football that are interested in maximizing success through and individual approach towards the implementation of training.
... Players are selected from a roster of 53 to 120, depending on the time of the season and the level (i.e. collegiate vs professional) with specialist positions across defense, offense and special teams [101]. Factors that set this sport apart includes the vast differences in positional characteristics, the mandatory inclusion of personal equipment (i.e., helmets and pads) that in turn likely influences the magnitude of collisions, and the prolonged time course over which the game is played. ...
Article
Full-text available
Seeking to obtain a competitive advantage and manage the risk of injury, team sport organisations are investing in tracking systems that can quantify training and competition characteristics. It is expected that such information can support objective decision-making for the prescription and manipulation of training load. This narrative review aims to summarise, and critically evaluate, different tracking systems and their use within team sports. The selection of systems should be dependent upon the context of the sport and needs careful consideration by practitioners. The selection of metrics requires a critical process to be able to describe, plan, monitor and evaluate training and competition characteristics of each sport. An emerging consideration for tracking systems data is the selection of suitable time analysis, such as temporal durations, peak demands or time series segmentation, whose best use depends on the temporal characteristics of the sport. Finally, examples of characteristics and the application of tracking data across seven popular team sports are presented. Practitioners working in specific team sports are advised to follow a critical thinking process, with a healthy dose of scepticism and awareness of appropriate theoretical frameworks, where possible, when creating new or selecting an existing metric to profile team sport athletes.
... This conclusion is consistent with the fi ndings of Merlino, et al. [8], who found a signifi cant prevalence of knee pain [9][10][11][12][13][14][15][16][17][18]. ...
... As this biomechanical, noncontact pivoting mechanism may be related to fatigue from overuse and neuromuscular deconditioning, 28,29 it is prudent to continue evaluating whether "load management" strategies are effective in reducing the risk of reinjury. 30,31 Given the prevalence e1382 of ACL injury in NFL players and the high degree of collisions that place relatively large stresses on the reconstructed knee, 11,[32][33][34] there has been a concerted effort to address a player's return to full-time duty and determine appropriate game utilization while minimizing reinjury. 1,4,26,35,36 The present results did indicate that players picked with higher draft positions were significantly more likely to start in games the season after RTP from ACL reconstruction. ...
Article
Full-text available
Purpose The purpose of this study is to evaluate differences in game utilization or performance following primary anterior cruciate ligament (ACL) reconstruction between National Football League (NFL) players with and without a second ACL injury. Methods NFL players who underwent ACL reconstruction between 2013 and 2017 were identified. Players were classified as having one injury (“tear”) or having later sustained a subsequent second (reinjury or contralateral) ACL injury (“retear”). Players were excluded if they tore their ACL prior to the NFL, did not return to play (RTP), did not play the season before injury, or had concomitant injuries. Demographic characteristics, game utilization statistics, and season approximate value (SAV) performance metrics were recorded. Statistical analysis compared data after RTP from primary ACL reconstruction (seasons +1, +2, and +3) relative to the season before injury (season −1) between cohorts using mean differences and relative percentages. Results Analysis included a total of 45 players, 32 in the “tear” group and 13 in the “retear” group. Demographics, level of play, and time to RTP after primary ACL reconstruction did not differ between the groups (P > .05). Tear and retear groups demonstrated similar utilization and performance metrics the season prior to injury (−1) and the 3 seasons following RTP (season of injury is “0”). Both groups had a similar decrease (relative percentage) in games played and started, snap counts, and SAV during the 3 seasons following RTP compared to baseline (P > .05). The draft pick position was correlated with the relative percentage of games started the first season after RTP (r = .6, P = .02). Conclusions Game utilization and performance metrics following ACL reconstruction were not associated with a subsequent second ACL injury. Players with a higher draft pick position were more likely to return to the starting lineup following primary ACL reconstruction. Ultimately, player game utilization and performance following primary ACL reconstruction is not predictive of a subsequent second ACL injury. Level of Evidence Level III, retrospective case-control study
Preprint
The purpose of this study was to know the bone changes of college football players. A total of 39 male football players participated, ranging in age from 18 to 25 years. They were grouped according to each playing position they play as: linemen (n= 15), high skill players (n= 7), skill players (n= 13) and quarterbacks (n= 4). For the assessment of BMD (g / cm2), a Dual X-Ray Absorptiometry (DXA) was used. The results obtained from this study showed a significant decrease (p <.05) of BMD in the head and legs. In contrast, the BMC showed an increase in legs, however, in the pelvic region it showed a significant decrease (p <.05). In conclusion, significant changes were found for BMD and BMC in the head, leg and pelvic regions in college football players within one year.
Article
Full-text available
Purpose: To investigate the recovery time course of customized wellness markers (sleep, soreness, energy and overall wellness) in response to match play in Division 1-A American Collegiate Football players. Methods: A retrospective research design was used in this study. Wellness data was collected and analysed for two collegiate American football seasons. Perceptions of soreness, sleep, energy and overall wellness were obtained daily for the day preceding each game (GD-1) and the days following each game (GD+2, GD+3 and GD+4). Standardised effect size (ES) analyses±90% confidence intervals were used to interpret the magnitude of the mean differences between all time-points for the START, MIDDLE and FINISH of the season, using the following qualitative descriptors: 0-0.19 trivial; 0.2-0.59 small; 0.6-1.19 moderate; 1.2-1.99 large; <2.0 very large. Results: Overall wellness showed small ES reductions on GD+2 (d=0.22±0.09, likely [94.8%]), GD+3 (d=0.37±0.15, very likely) and GD+4 (d=0.29±0.12, very likely) compared to GD-1. There were small ES reductions for soreness between GD-1, and GD+2, GD+3 and GD +4 (d=0.21±0.09, likely, d=0.29±0.12, very likely, and 0.30±0.12, very likely, respectively). Small ES reductions were also evident between GD-1 and GD+3 (d=0.21±0.09, likely) for sleep. Feelings of energy showed small ES on GD+3 (d=0.27±0.11, very likely) and GD+4 (d=0.22±0.09, likely) when compared to GD-1. Conclusions: All wellness markers were likely-very likely worse on GD+3 and GD+4 compared to GD-1. These findings show that perceptual wellness takes longer than 4 d to return to pre-game levels and thus should be considered when prescribing training and/or recovery.
Article
Full-text available
Competitive athletes have goals to optimize performance and to maintain healthy body composition. Sports nutrition is a component of training programs often overlooked by student-athletes and their coaches. The purpose of this study was to examine student-athletes’ sports nutrition knowledge across sex, class level, team, and completion of prior nutrition coursework. Participants included 123 mid-major Division I university student-athletes (47 females and 76 males) from baseball, softball, men’s soccer, track and field, and tennis. The student-athletes completed a survey questionnaire to determine adequate sports nutrition knowledge (mean ≥ 75%). The overall mean sports nutrition knowledge score for the student-athletes was 56.9% which was considered inadequate sports nutrition knowledge (mean < 75%). Only 12 student-athletes achieved adequate sports nutrition knowledge score of 75% or higher. There were no differences by sex, class level, team, and completion of prior nutrition coursework. Student-athletes’ inadequate sports nutrition knowledge may place them at nutrition risk, lead to impaired performance, and affect their lean body mass and energy levels. Athletics personnel should not assume student-athletes have adequate sports nutrition knowledge. Athletic departments may make available a board certified Sports Dietitian or Registered Dietitian and offer classroom or online courses facilitating student-athletes to optimize nutrition knowledge and behaviors.
Article
Full-text available
Background: Research has found that injury rates in football are higher in competition than during practice. However, there is little research on the association between injury rates and type of football practices and how these specific rates compare with those in competitions. Purpose: This study utilized data from the National Collegiate Athletic Association Injury Surveillance System (NCAA ISS) to describe men's collegiate football practice injuries (academic years 2004-2005 to 2008-2009) in 4 event types: competitions, scrimmages, regular practices, and walkthroughs. Study design: Descriptive epidemiological study. Methods: Football data during the 2004-2005 to 2008-2009 academic years were analyzed. Annually, an average of 60 men's football programs provided data (9.7% of all universities sponsoring football). Injury rates per 1000 athlete-exposures (AEs), injury rate ratios (RRs), 95% CIs, and injury proportions were reported. Results: The NCAA ISS captured 18,075 football injuries. Most injuries were reported in regular practices (55.9%), followed by competitions (38.8%), scrimmages (4.4%), and walkthroughs (0.8%). Most AEs were reported in regular practices (77.6%), followed by walkthroughs (11.5%), competitions (8.6%), and scrimmages (2.3%). The highest injury rate was found in competitions (36.94/1000 AEs), followed by scrimmages (15.7/1000 AEs), regular practices (5.9/1000 AEs), and walkthroughs (0.6/1000 AEs). These rates were all significantly different from one another. Distributions of injury location and diagnoses were similar across all 4 event types, with most injuries occurring at the lower extremity (56.0%) and consisting of sprains and strains (50.6%). However, injury mechanisms varied. The proportion of injuries due to player contact was greatest in scrimmages (66.8%), followed by regular practices (48.5%) and walkthroughs (34.9%); in contrast, the proportion of injuries due to noncontact/overuse was greatest in walkthroughs (41.7%), followed by regular practices (35.6%) and scrimmages (21.9%). Conclusion: Injury rates were the highest in competitions but then varied by the type of practice event, with higher practice injury rates reported in scrimmage. In addition, greater proportions of injuries were reported in regular practices, and greater proportions of exposures were reported in regular practices and walkthroughs. Efforts to minimize injury in all types of practice events are essential to mitigating injury incidence related to both contact and noncontact.
Article
Full-text available
Background: Anterior cruciate ligament (ACL) injuries can have negative consequences on the careers of National Football League (NFL) players, however no study has ever analyzed the financial impact of these injuries in this population. Purpose: To quantify the impact of ACL injuries on salary and career length in NFL athletes. Study design: Cohort study; Level of evidence, 3. Methods: Any player in the NFL suffering an ACL injury from 2010 to 2013 was identified using a comprehensive online search. A database of NFL player salaries was used to conduct a matched cohort analysis comparing ACL-injured players with the rest of the NFL. The main outcomes were the percentage of players remaining in the NFL and mean salary at 1, 2, 3, and 4 years after injury. Cohorts were subdivided based on initial salary: group A, <$500,000; group B, ≤$500,000 to $2,000,000; and group C, >$2,000,000. Mean cumulative earnings were calculated by multiplying the percentage of players remaining in the league by their mean salaries and compounding this each season. Results: NFL athletes suffered 219 ACL injuries from 2010 to 2013. The 7504 other player seasons in the NFL during this time were used as controls. Significantly fewer ACL-injured players than controls remained in the NFL at each time point (P < .05). In group A, significantly less ACL-injured players remained in the NFL at 1 to 3 seasons after injury (P < .05), and in group B, significantly less ACL-injured players remained in the NFL at 1 and 2 seasons after injury (P < .05). There was no significant decrease in group C. Players in groups A and B remaining in the NFL also had a lower mean salary than controls (P < .05 in season 1). The mean cumulative earnings over 4 years for ACL-injured players was $2,070,521 less per player than uninjured controls. Conclusion: On average, ACL-injured players earned $2,070,521 less than salary-matched controls over the 4 years after injury. Players initially earning less than $2 million per year have lower mean salaries and are less likely to remain in the league than uninjured controls. The careers of players initially earning over $2 million per year, meanwhile, are not negatively affected. This demonstrates the degree of negative impact these injuries have on the careers of NFL players. It also indicates that a player's standing within the league before injury strongly influences how much an ACL injury will affect his career.
Article
Full-text available
Background: Injury rates are high for collegiate football players. Few studies have evaluated the epidemiology of surgical procedures in National Collegiate Athletic Association (NCAA) Division I collegiate football players. Purpose: To determine the most common surgical procedures performed in collegiate football players over a 10-year period. Study design: Descriptive epidemiological study. Methods: From the 2004-2005 season through the 2013-2014 season, all surgical procedures performed on athletes from a single NCAA Division I college football team during athletic participation were reviewed. Surgeries were categorized by anatomic location, and operative reports were used to obtain further surgical details. Data collected over this 10-season span included type of injury, primary procedures, reoperations, and cause of reoperation, all categorized by specific anatomic locations and position played. Results: From the 2004-2005 through the 2013-2014 seasons, 254 operations were performed on 207 players, averaging 25.4 surgical procedures per year. The majority of surgeries performed were orthopaedic procedures (92.1%, n = 234). However, there were multiple nonorthopaedic procedures (7.9%, n = 20). The most common procedure performed was arthroscopic shoulder labral repair (12.2%, n = 31). Partial meniscectomy (11.8%, n = 30), arthroscopic anterior cruciate ligament (ACL) reconstruction (9.4% n = 24), and arthroscopic hip labral repair (5.9% n = 15) were the other commonly performed procedures. There were a total of 29 reoperations performed; thus, 12.9% of primary procedures had a reoperation. The most common revision procedure was a revision open reduction internal fixation of stress fractures in the foot as a result of a symptomatic nonunion (33.33%, n = 4) and revision ACL reconstruction (12.5%, n = 3). By position, relative to the number of athletes at each position, linebackers (30.5%) and defensive linemen (29.1%) were the most likely to undergo surgery while kickers (6%) were the least likely. Conclusion: In NCAA Division I college football players, the most commonly performed surgeries conducted for injuries were orthopaedic in nature. Of these, arthroscopic shoulder labral repair was the most common, followed closely by partial meniscectomy. Nonorthopaedic procedures nonetheless accounted for a sizable portion of surgical volume. Familiarity with this injury and surgical spectrum is of utmost importance for the team physician treating these high-level contact athletes.
Article
Full-text available
The purpose was to examine a round trip trans-American jet travel on performance, hormonal alterations, and recovery. Ten matched pairs of recreationally trained men were randomized to either a compression group (COMP) (n= 10, age: 23.1 ± 2.4 years, height: 174.8 ± 5.3cm, body mass: 84.96 ± 10.16 kg, body fat: 15.3 ± 6.0%) or control group (CONT) (n= 9, age: 23.2 ± 2.3 years, height: 177.5 ± 6.3cm, body mass: 84.35 ± 8.99 kg, body fat: 15.1 ± 6.4%). Subjects flew directly from Hartford, CT to Los Angeles, CA one day prior to a simulated sport competition (SSC) designed to create muscle damage and returned the next night on a overnight flight back home. Both groups demonstrated jet lag symptoms and associated decreases in sleep quality at all time points. Melatonin significantly (P < 0.05) increased over the first two days and then remained constant after the SSC. Epinephrine, testosterone, cortisol values significantly increased above resting values before and after the SSC with norepinephrine increases only after the SSC. Physical performances significantly decreased from control values on each day for the CONT group with COMP group exhaibiting no significant declines. Muscle damage markers were significantly elevated following the SSC with the COMP group having significantly lower values while maintaining neuromuscular performance measures that were not different from baseline testing. Trans-American jet travel significantly impacted parameters related to jet lag, sleep quality, hormonal responses, muscle tissue damage markers, and physical performance with an attenuation observed with extended wear compression garments.
Article
We have now been provided with a toll free link to this paper which will be available for a limited time: http://bjsm.bmj.com/content/early/2016/12/01/bjsports-2016-096770.full.pdf?keytype=ref&ijkey=pla87sNQyzzHmGr
Article
Background: Sports-related concussions (SRCs) have gained increased societal interest in the past decade. The National Collegiate Athletic Association (NCAA) has implemented legislation and rule changes to decrease the incidence and risk of head injury impacts. The "targeting" rule forbids initiating contact with the crown of a helmet and targeting defenseless players in the head and neck area; however, there are concerns that this rule change has unintentionally led to an increased incidence of lower extremity injuries. Purpose/hypothesis: The purpose of this study was to evaluate the change in lower extremity injury rates in NCAA football during the 2009-2010 to 2014-2015 seasons. We hypothesized that the lower extremity injury rate has increased across the time period. Study design: Descriptive epidemiology study. Methods: Sixty-eight NCAA football programs provided 153 team-seasons of data to the NCAA Injury Surveillance Program. Lower extremity injuries (ie, hip/groin, upper leg/thigh, knee, lower leg/Achilles, foot/toes) and SRCs sustained during NCAA football games were examined. We calculated injury rates per 1000 athlete-exposures (AEs) for lower extremity injuries and SRCs. Rate ratios (RRs) compared injury rates between the 2009-2010 to 2011-2012 and 2012-2013 to 2014-2015 seasons. Results: Overall, 2400 lower extremity injuries were reported during the 2009-2010 to 2014-2015 seasons; most were to the knee (33.6%) and ankle (28.5%) and caused by player contact (59.2%). The lower extremity injury rate increased in 2012-2013 to 2014-2015 compared with 2009-2010 to 2011-2012 (23.55 vs 20.45/1000 AEs, respectively; RR, 1.15; 95% CI, 1.06-1.25). This finding was retained when restricted to injuries due to player contact (RR, 1.19; 95% CI, 1.07-1.32) but not for injuries due to noncontact/overuse (RR, 0.96; 95% CI, 0.80-1.14). When examining player contact injury rates by anatomic site, only ankle injuries had an increase (RR, 1.36; 95% CI, 1.13-1.64). The SRC rate also increased in 2012-2013 to 2014-2015 compared with 2009-2010 to 2011-2012 (3.52 vs 2.63/1000 AEs, respectively; RR, 1.34; 95% CI, 1.08-1.66). Conclusion: The lower extremity injury rate has increased in NCAA football athletes. Similarly, SRC rates have increased, although this may be caused by concurrent policies related to better education, identification, and management. Targeting rule changes may be contributing to increased rates of player contact-related ankle injuries. Alongside continued surveillance research to examine longitudinal time trends, more in-depth individual-level examinations of how targeting rule changes influence coaching and player behaviors are warranted.
Article
Objective: To present data on the rate of anterior cruciate ligament (ACL) injury in 15 collegiate sports from 2004 to 2005 through 2012 to 2013 updating the 1988-1989 to 2003-2004 data. Design: Prospectively designed descriptive epidemiology study. Setting: National Collegiate Athletic Association Schools. Participants: National Collegiate Athletic Association School athletes. Main outcome measure: Injury rate by year and sport. Results: Most ACL injuries to women occurred by a noncontact mechanism (60%) versus a contact mechanism for men (59%). The highest average annual rate of ACL injury for men was found in football (0.17 per 1000 athlete-exposure [A-E]). The highest average annual rate of ACL injury for women was found in lacrosse (0.23 per 1000 A-E). There were statistically significant increases in average annual injury rate for men's (P = 0.04) and women's soccer (P = 0.01) and a statistically significant decrease in women's gymnastics over the 9 years (=0.009). Controlling for exposures, there were statistically significant increases in the average annual number of injuries for men's and women's basketball, ice hockey, field hockey, football, and volleyball and a decrease in the average annual number of injuries for baseball and women's gymnastics. Women continue to sustain ACL injuries at higher rates than men in the comparable sports of soccer, basketball, and lacrosse. Conclusions: Anterior cruciate ligament injury rates continue to rise in men's and women's soccer. Some sports have shown absolute increases in ACL rates, which persist even after exposure rates are taken into account. Clinical relevance: Despite extensive research and development of prevention programs before and during the time of this study, very few sports showed a reduction in ACL injury rates in this data set.