Different athletes have different body types and compositions based on the sport they play. This is a natural phenomenon, as different exercises require muscle groups to work in various ways, altering the structure and composition of the body.

A study published in the Open Access Journal of Functional Morphology and Kinesiology looks at how athletes within American Football teams have different body compositions and performance indicators depending on their positions within the team. The research, carried out by scientists from the University of Kansas, analyzed different factors, such as body weight, flexibility, mobility, speed, muscle strength, and body mass.

The first author of the study, Dr. Johnson discusses the diversity of players within a team:

Even within the same sport you have different body types and different needs for the position they play,” Johnson explained. “Speed, mobility, and flexibility all play a part in your ability to play football. Strength and power also play a huge role

How different sports change the body

By simply watching different athletes carry out their chosen sport, we can see how repeated exercise of the same type changes the way our bodies look. For example, weight lifters possess much more overall body and muscle mass compared to marathon runners, whose body compositions are trained in a certain way to endure long distances.

Professional athletes undergo rigorous training with a team of expert coaches to ensure that they can obtain the most optimum biomechanical physical attributes demanded by the sport, allowing them to compete with the highest possible advantage.

However, some individuals have a predisposed genetic advantage for performing specific sports, making it more ‘natural’ for the individual to train; in essence, most high-level athletes possess a natural talent that can be honed and perfected by training and practice.

These indicators can be tracked and analyzed, which is what researchers did with players from the National Collegiate Athletic Association Division-II American Football.

Analysing physical attributes of athletes within the same team

In the study, researchers analyzed the physical features and capabilities of sixteen athletes playing in different positions within the football team. The analyzed factors included:

• Body composition (height, fat, bone, muscle, water content)
• Joint kinematics (studying how the body’s joints react to forces and movement in motion)
• Muscular strength
• Muscular power
• Flexibility
• Stability

Upon analyzing these different components, the researchers found significant differences between the athletes, highlighting the importance of specific physical attributes and abilities depending on the position played.  To analyze athleticism, the players carried out a series of movements such as jumps and squats whilst being monitored with technology such as markerless motion capture and force plates.

The study confirmed the original hypothesis of the researchers, where they expected a difference between body compositions, meaning that football players in particular positions would possess certain features. The findings showed how linebackers in particular (those playing in the first line of defence), possessed a higher body mass compared to other members of the team.

“Speed, mobility, and flexibility all play a part in your ability to play football. Strength and power also play a huge role. We found significant differences among position groups in muscular power, as well as muscular strength. However, we didn’t find a difference in flexibility.” – Dr. Johnson.

They also found that high-skill players such as quarterbacks were able to jump higher and with a greater force compared to linemen. However, there was no difference in the capacity of movement and flexibility between the players.

Why is sports science research important?

The research provides up-to-date knowledge on how athletes differ in body composition and physical abilities. Dr Johnson discusses the purpose of the research and what they hope to achieve in the future:

I hope to help answer questions coaches have and hopefully move the field in some new directions. The big question is, ‘Can we assess the abilities of this group of athletes? Once we have this information, can we analyze it in a way that over time improves performance?

The research will be beneficial to help trainers and coaches understand the intricacies of different body compositions to help maximize their teams’ abilities and play to their full potential. It could also be useful beyond the realm of training, where healthcare professionals and sports scientists could use this knowledge to build on future research of biomechanics and human physiology in the context of exercise.

To learn more about research in this area, access the Journal of Functional Morphology and Kinesiology or access the full journal list.