Infrared thermography and monitoring in collegiate American football

Infrared thermography represents a significant advancement in athlete monitoring, offering a non-invasive method for collecting crucial temperature data. Sports organizations increasingly recognize the value of this technology for athlete care programs, particularly for injury surveillance.

Infrared thermography devices capture thermal information through heat sensitive sensor arrays, displaying it as a thermogram that reveals temperature variations across different regions. The technology’s effectiveness is supported by extensive research examining thermal patterns in various conditions, including inflammation, skin conditions, ligament tears, and muscle strains across diverse sporting environments. Handheld devices are the most common form of infrared thermography technology in sport. These units resemble digital cameras and produce quick, targeted scans. The output is as a color coded heat map where red / white areas indicate higher temperatures, blue / purple areas show cooler temperatures, and yellow / green areas represent normal temperature ranges.

A leading application involves analyzing tissue temperature variations as indicators of athletic performance and musculoskeletal condition. One of the technology’s key advantages is its immediacy–practitioners can view results in real time and make instant comparisons with baseline measurements or previous scans.

Consider a typical scenario: A college football player enters the training facility after a Saturday game. He’s met by a sport scientist equipped with a handheld thermography device. Within seconds, the performance staff is looking at targeted scans or quick full body assessments, immediately evaluating this snapshot of the athlete’s tissue temperature patterns. This real time data enables early identification of potential issues, allowing for proactive intervention in the athlete’s training program.

Infrared thermography offers an innovative solution for proactive injury surveillance, enabling coaching and medical staff to monitor tissue health through regular assessments; track rehabilitation progress; evaluate player readiness for competition; and make informed decisions about training modifications.

Thermography shows us what the body is doing

Infrared thermography perceives heat signatures while enabling instantaneous information capture across large areas. The technology operates on a fundamental thermodynamic principle. All objects emit infrared radiation based on their temperature. As an object’s temperature increases, it emits more energy as infrared radiation. This principle applies universally to both animate and inanimate objects.

The human body maintains an average skin temperature of approximately 35-36° Celsius, reflecting the optimal operating temperature of various body systems. Blood flow to the skin can change significantly in response to both central and local physiological factors, and blood flow changes affect surface temperature patterns. Temperature differences greater than 0.7°C between symmetrical body parts often indicate potential issues.

Baseline scanning during preseason involves full body scans. These document each player’s “heat signature” and their normal temperature patterns. Periodic full body scans throughout the season let practitioners track any major changes. In between those macro scans, quick pre- and post-practice scans provide a look at performance and injury vulnerability factors. If the player reports any pain, instability, or anything else adverse, we can take a targeted scan on his area of concern.

Temperature differentials and heat distribution patterns are two of the main things practitioners look for on the heat map. Patterns of heat distribution can suggest acute inflammation (localized high temperatures), chronic conditions (persistent temperature variations), and a player’s recovery progress (gradual return to baseline patterns).

With infrared thermography, heat becomes the primary indicator of injury development at the tissue level. Infrared imaging captures heat signatures that enable coaches and trainers to assess injury severity with unprecedented precision.

The ability to assess inflamed tissue through infrared imaging immediately after injury is particularly important when dealing with muscle discomfort or mild head injury symptoms. Early access to injury information leads to more timely and appropriate treatment, potentially improving recovery outcomes and overall athlete health. The technology eliminates the need for coaches to rely solely on subjective questioning to determine post-workout soreness or potential mild head injuries. Instead, objective temperature monitoring and related metrics facilitate immediate assessment of an athlete’s true health status, enabling more informed decisions about participation and recovery protocols.

Integrating thermography into athlete monitoring

As monitoring techniques become increasingly sophisticated, programs may focus on optimizing specific aspects of athlete training.

For fatigue monitoring, power output correlates with the physiological response revealed by infrared thermography. The output allows practitioners to analyze muscle group oxygen use, and patterns in how the body dissipates heat. Practitioners interested in training response can evaluate the physiological impact of specific exercises, tracking recovery rates and measuring thermal responses to varying training loads (e.g., intensity, speed of movement).

With the level of specificity infrared thermography provides, practitioners can develop specific protocols and considerations based on positions and movements. For example, heavy football players, particularly offensive and defensive linemen, typically exhibit higher muscle temperatures. Their proximity to the line of scrimmage requires faster reactions and different preparation approaches. Conversely, smaller, more agile players in positions further from center generate movements with greater torque, demanding distinct physiological responses.

Research using infrared thermography in team sports has revealed valuable insights for monitoring and support. Studies analyzing the impact of competitive games on football athletes have shown that software generated data can effectively indicate soft tissue injury severity, guiding sports medicine teams in reassessment and return to play decisions. Research has also demonstrated that data from individual players during games or seasons can help tailor training programs.

Cutting-edge tech becomes an everyday tool

The medical staff for the University of Miami football team comprised a head team physician, head athletic trainer, and a staff of athletic trainers. The coaching staff included the head of sport science and performance coaches. The performance enhancement team developed the implementation from concept to onboarding.

This multi-disciplinary team identified key threats, challenges, and solutions. The threats to good usage of infrared thermography are the glacier approach—the little you see vs. the much greater amount you don’t see—and the quality of data and decision making. The top challenges were understanding the medical and athletic applications of infrared technologies, and defining system integration points. To address these, we looked at integrating communication between the subunits of the team: breaking down the informational silos that can arise. We addressed the pace of implementation, how to ensure data quality, and procedures to maintain open communications. We also identified testing points to monitor training and competition load.

We deployed infrared thermography to acquire and leverage players’ thermographic images pre- and post- training, with the ultimate aim of improving performance. Repeated assessments with this technique have demonstrated substantial improvements in a range of metrics including range of motion and muscle force. Some researchers went so far as to say “thermographic images have the power to predict with near-perfect precision the individual loads during a workout, based on hormonal levels alone with a statistical significance.”

One of our football players commented, “I always see pictures and I just thought they documented sweat. Then I saw how the most recent ones compared to the pictures from the start of the season. I knew my body has changed a lot, but these showed everything!”

The vast majority of feedback gathered through the assessment process emphasizes the positive effects of thermographic technology on a range of performance assessment and management activities.

A somewhat counter-intuitive observation about training is that while the weight room programs are given in units of kilograms, and the loads and training levels vary considerably between freshman and seniors, we found we could group athletes based on their hormonal composition alone, even without knowing their actual hormonal status, based on time for an individual exercise. The thermographic image lets practitioners derive the estimated time for a player to perform a given exercise. Players doing a given exercise can provide immediate feedback on whether modifications benefit or hinder their subjective performance, which the staff can cross check against the thermography.

It’s a given, at this point, that a one-size-fits-all approach does not work. Objective real time data guides the coaching and medical staff towards true individualization while, at the same time offering a new look at bucketing players.

Future uses of infrared thermography

Infrared technology is advancing to produce higher quality thermal images at faster acquisition speeds. This is exemplified in the latest infrared sensor devices with incredibly quick refresh and imaging rates.

To produce the imagery live with an on-board processor, some of these cameras are even powered with graphical processing software. The microbolometer is the passive image sensing device, which was previously slower and responsible for a reduced spatial resolution and slower frame rates. New methodologies to produce fast acquisition are relying on read-out integrated circuits instead of conventional sensor designs.

Such improvements in infrared technology could be of great benefit when monitoring athletes by making the outputs more accurate and reliable.

The faster and more accurate devices open even more doors for applying thermography in sports settings. Many monitoring technologies ultimately rely on the athlete being properly diagnosed with an injury. The practitioners then interpret all subsequent outputs (e.g., force plate data, velocity based training, even body composition) through the lens of that knowledge: “Given their injury, we expect to see…” Infrared thermography, on the other hand, let’s the practitioner go in “blind” to any injuries and still make a valid, reliable, and objective analysis of the athlete’s current condition.

One application we are working on is a “heat budget.” This would compare the energy an athlete expends while training to their thermal flow at each test, and then standardizing this metric. This could be an effective clinical-mechanical way to evaluate training under various metabolism or hydration conditions.

Wearables have become a regular part of the sports technology stack, and offer another point of integration with infrared thermography. Cross-referencing vital metrics that come off of wearables such as heart rate, respiratory rate, body temperature, and oxygen saturation with each athlete’s in-the-moment and long term heat signatures will provide new insights into understanding how athletes’ bodies respond to environmental factors and training conditions.

The ability to transfer athlete data to coaches through handheld devices aids in enhancing medical and scientific knowledge. However, a central ethical concern surrounding these wearable technologies are the issues of data privacy and storage. Despite this challenge, there are ways to share important information securely while ensuring compliance with data protection regulations.

An athlete’s output, whether in the gym or on the field on gameday, is directly dependent on their internal state. The more performance practitioners can understand about what is going on in each athlete’s body, the better they can improve athlete outcomes. Infrared thermography is a significant leap forward, and will be the source of important insights and new discoveries for any practitioner or department who brings it into their suite of training tech.