The Science of American Football

Jay Hoffman

• Publisher: Routledge
• Year: 2020
• ISBN:
  9781000215397
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Sport & Exercise Science
• Index: Biological Sciences

The game of American football may be the greatest team sport that exists. It epitomizes the need of a "team" first approach to achieve the desired success. Success is often measured as the hoisting of a championship trophy, which involved a journey that required discipline, perseverance, sacrifice, and hard work. These traits are the backbone of success in football, but more importantly they are the backbone or blueprint for success in life.

The Science of American Football provides an in-depth discussion on the physiology of the game of American football, including the physiological strain associated with playing in various environmental extremes. Acclimatization, preparation, and medical issues associated with each of these environmental extremes are discussed as well as medical issues occurring during the athlete's playing career (common sites of injury) and potential risks arising post-career (e.g. neurological dysfunction, arthritic joints, obesity).

The book goes on to consider aspects of player selection and preparation, including discussion of evidence-based physical conditioning programs, appropriate nutrition, and specific dietary supplementation for the American football player.

The Science of American Football is the first book to focus on the physiology, science, and medical issues associated with the game of American football and will be key reading for students of coaching and exercise science as well as those with a keen interest in understanding the science of American football, such as coaches and players.

1

PHYSIOLOGY OF AMERICAN FOOTBALL

Introduction

Despite football being one of the most popular sports in North America, whose global outreach is growing stronger every year, the scientific understanding of the game is less than any of the other major sports such as soccer, basketball, or even baseball. This is likely related to the relatively low number of games played during the season and the inability to simulate a game or have a practice game for the benefit of scientific discovery. In addition, the imaginary wall between academics and athletics across college campuses around the nation has unfortunately limited the degree of collaboration. As such, the ability to study football players during an actual competitive event has been very limited.

The vast majority of research in American football has focused on the physical requirements of the game. Research of the past 30 years has clearly demonstrated the importance of strength, power, and speed at all competitive levels (Berg et al., 1990; Black and Roundy, 1994; Fry and Kraemer, 1991; Garstecki et al., 2004; Kraemer and Gotshalk, 2000). Investigations have shown that strength, power, and speed can differentiate starters from nonstarters and may also differentiate athletes between different levels of competition (Berg et al., 1990; Fry and Kraemer, 1991; Kraemer and Gotshalk, 2000). The evidence from these investigations has assisted football coaches and scouts regarding the type of athlete to recruit and has also generated a degree of scientific curiosity for sport scientists to examine various training paradigms and their potential effect on improving athletic performance in football players (Hoffman et al., 2004a, 2005a, 2009a). Performance improvements in college football players appear to occur in the early part of the athlete’s playing career (Hoffman et al., 2011; Miller et al., 2002), with a much lower rate of improvement observed in subsequent years. This will be covered in greater detail in Chapter 3.

Physiological Demands of American Football

The number of physiological studies conducted on the sport of American football is very limited in comparison to the large body of work on strength, power, or speed development. The separation often seen between sport science and university athletic programs, especially at the National Collegiate Athletic Association (NCAA) Division I level within the United States, is likely in part responsible for this paucity of data (Hoffman, 2015). But there are many other reasons as well, including the lack of appreciation for the potential contributions that sport science can make, the limited access to conduct invasive procedures (e.g., blood draws or muscle biopsies), and an inability of the research team to conduct a field study. There have only been a limited number of studies that have examined the physiological stress of a game or a competitive season. Much of our understanding regarding the physiological requirements of the game is based primarily on empirical evidence. Recently, technological advancements have provided a noninvasive approach (i.e., global positioning systems [GPS]) to examining specific movement patterns of football players during competition, which has helped further our understanding and has increased our ability to determine physiological and metabolic demands placed on these athletes.

The Game of Football

There are 22 athletes on the field at all times. Eleven of those athletes play offense, while the other 11 athletes play defense. The overall goal of the offense is to score: Whether it is touchdown in which an offensive player carries the ball across the goal line, which is worth six points, or they kick a field goal, which is worth three points. After a touchdown, the offense can kick an extra point worth one point, or attempt to score (run or pass) the ball from the 3-yard line into the end zone for two points. The offensive team comprises five linemen (two tackles, two guards, and a center). The responsibility of the center is to snap the ball to the quarterback. The guards line up on either side of the center, while the tackles are positioned on the outside shoulder of the guards. All five of these linemen are generally in a three-point stance. There are certain instances when the guards and tackles may be in a two-point stance with their hands on their thighs. These athletes are generally the bigger players on the field whose primary responsibility is to protect the quarterback when he passes the ball, or block for the running backs as they run the ball. The other players on the offensive side of the ball are considered to be “skill position players” and include a quarterback, whose responsibilities include calling the plays, passing the ball, or running with the ball. The quarterback is expected to be the leader of the offense. He is given the play by the coach and has the responsibility to run that play or decide based upon the defensive alignment that a different play may be more appropriate. This decision-making requirement adds a significant cognitive load to the quarterback. The other skill position players include one or two running backs and three or four wide receivers. Running backs have several responsibilities that include taking a hand-off from the quarterback and running the ball. They may also be required to catch the ball when it is thrown, and they may also have blocking responsibilities. The wide receivers generally are required to catch the ball when it is thrown by the quarterback and block during running plays. They are generally the faster athletes on the offensive team. One of the receivers may be a tight end. He lines up next to one of the tackles on the outside shoulder (hence the term “tight”) and is generally a bigger athlete who has greater blocking responsibility than the other receivers. The other receivers generally line up away from the linemen (hence the term “wide”). The skill position players generally begin the play in a two-point stance; however, the tight end often lines up in a three-point stance.

On the defensive side of the ball, the positional composition of the team can vary depending upon the schemes of the coach, or in response to the substitution pattern of the offense. In general, the defense consists of a combination of three to four defensive linemen, three to four linebackers, and four to five defensive backs. The goal for each defensive player is to react to what the offense is attempting to do and prevent the offense from scoring. The defense also has the ability to score a touchdown from either intercepting a pass and running it into the end zone or recovering a fumble (e.g., a ball that is knocked away from one of the offensive skill position players) and running the fumble into the end zone. Defensive linemen are generally in a three-point stance and are positioned either “head-up” or “shaded” to either the inside or the outside shoulder of an offensive lineman. They position themselves as close to the line of scrimmage (e.g., where the ball is placed) as possible. The linebackers are generally positioned 5 yards off the ball and are in a two-point stance. The defensive backs are often divided into cornerbacks and safeties. The cornerbacks are responsible for covering the fastest players on the field – the wide receivers, while the safeties will also cover wide receivers, but they may also be responsible for covering the tight end or running backs. Regardless, the defensive backs are often the smaller but faster players on the defensive side of the ball.

Player substitutions during a football game are unlimited, so players can be interchanged between each play. Depending on the type of play that the offensive coach calls, he may substitute a wide receiver for a running back for a pass play. To counter that substitution, the defensive coach may substitute another defensive back for either a defensive lineman or a linebacker. The only rule regarding players is that the offense is required to have at least five offensive linemen on the field, and a total of seven players have to line up on the line of scrimmage (where the ball is placed). The other four players can line up anywhere behind the line of scrimmage, but they are not permitted to be on the line of scrimmage. Offensive linemen are not eligible to catch the ball or go past the line of scrimmage until the ball itself crosses the line of scrimmage. In contrast, the defensive players are permitted to line up in any location on the field.

In general, football players participate as only offense or defense. The physical demands of the game require maximum intensity on each play that often involves a collision with another player. The intensity of the game has generally eliminated “two-way” players, especially at the higher levels of competition (e.g., college or professional). In youth football, or perhaps even in high school football, some players may have both an offensive position and a defensive position. As discussed earlier, each position on the field has specific responsibilities that create a different physical requirement. The specific distance of movement is also dependent upon the player’s position. Offensive and defensive linemen are generally lineup across from one another, which may require a very short distance of movement. Skill position players generally run for greater distances (i.e., 20–40 m) on each play, but they may not experience a physical confrontation on each play. Although the distance that ea...