It has long been known that different positions on the football field are suited to different body types. A study conducted by the University of Kansas went beyond the simple knowledge that referees are larger and have more body mass than receivers, testing a team of college football starting players and finding differences in strength, power, jump ability, and more. Researchers argue that the findings could help in developing strength training programs designed to optimize performance for different player types.

Even casual football fans can recognize that players in different positions have different body types. For example, midfielders tend to be larger and have more body mass, while forwards are smaller and faster. However, a new study conducted at the University of Kansas lays the groundwork to determine whether there are subtler differences in conditioning and strength characteristics by position, even those not immediately obvious to the trained eye.

Coaches and trainers may note that defensive players generally have higher upper body strength, while tight ends tend to have higher levels of flexibility, or they may point to data showing similar measurements. This could lead to position-specific training and placing athletes in the most optimal positions for success. Quincy Johnson, assistant professor in Health, Sports, and Exercise Science, led a study that used the latest technology to assess the basic performance indicators of a group of college football players, finding significant differences by position type in terms of body type, muscle strength, and power, even though flexibility didn’t show noticeable differences.

The focus of the study was on "big skill" positions such as offensive and defensive linemen, defensive players, and tight ends, as well as skill positions like quarterbacks, wide receivers, and safeties. Researchers administered a series of tests to 16 starting players from an NCAA Division II football team. All participants had not experienced musculoskeletal injuries and regularly participated in strength and conditioning training.

Johnson stated, "Even in the same sport, you have different body types and different needs based on the position they play. Speed, mobility, flexibility—these all play a role in your ability to play football. Strength and power also play a significant role. We found important differences in muscle strength as well as muscle power between position groups, but we didn’t find any differences in flexibility."

The players in the sample were divided into offensive and defensive groups and tested for body composition, including height, body mass, and lean body mass. Performance indicators such as movement capacity, muscle strength, and power were then measured. Technology, including motion capture and force plates, was used to measure movement capacity during squats, power during isometric thigh mid-pulls, jump power during jump exercises, and other similar measurements.

As expected, the researchers found significant differences in body composition; linemen had more body mass than other big-skilled players. Additionally, secondary position players showed higher jumps and were able to transfer power more efficiently during jumps, exhibiting different athletic characteristics across positions. However, it was not confirmed that movement capacity differed significantly by position.

The researchers noted that specific muscle strength and power measurements also varied between position groups, but peak strength measurements did not change. They emphasized that this finding underscores the importance of developing absolute strength.

Johnson, a former college football player and strength and conditioning coach, described the study as a call to action. By showing that different body compositions, movement capacities, and types of power and strength can be scientifically measured, the study may lay the groundwork for research aimed at maximizing desired characteristics to enhance long-term performance. More research is needed to determine the best way to develop the necessary characteristics for each position.

The study, written by Johnson, Yang Yang, Dimitrije Cabarkapa, and Andrew Fry from KU, Shane Stock, Dalton Gleason, Kazuma Akehi, Dayton Sealey, and Clay Frels from Nebraska-Kearney University, and Douglas Smith from Oklahoma State University, was published in The Journal of Functional Morphology and Kinesiology.

Johnson said, “I hope to help answer coaches' questions and take the field in new directions. The big question is: ‘Can we evaluate the abilities of athletes in this group? Once we have this information, can we analyze it over time to improve performance?’”

Johnson, who began playing football at age 5 in his hometown of Oklahoma, had questions about training camp when he reached the university level, such as why the first few and last few days of camp are the most exhausting and taxing on the body. Though he never suffered serious injuries, he saw many teammates who were injured or left the sport for various reasons. By approaching these kinds of questions with sports science, Johnson hopes to help athletes, coaches, trainers, and others use data to optimize performance. Such data could contribute to, for example, training regimes designed specifically for defensive backs to reach their full potential or help linemen stay on the field or avoid injuries.

Future studies will also examine data from Division I football players and athletes in other sports.

The authors note that the findings could be helpful not only for athletes and coaches but also for strength and conditioning experts, sports scientists, sports medicine specialists, nutritionists, and registered dietitians.

Johnson’s research is part of the work conducted at the Jayhawk Athletic Performance Laboratory, a member of the Wu Tsai Human Performance Alliance. The Alliance works to transform and improve human health through understanding optimal performance. While much of understanding human health comes from studying diseases, research at KU and its partners examines the highest athletic performance to help people achieve optimal health and well-being.