Spring 2026
Comparing EOD suits and conventional PPE load-carriage demands
In the realm of military and law enforcement operations, the importance of protective gear cannot be overstated. One crucial aspect of this gear is load carriage — the ability to carry essential equipment while maintaining mobility and minimizing fatigue. While traditional load-bearing systems have long been a staple in the tactical world, a specialized category of protective wear stands out: the explosive ordnance disposal (EOD) suit, or bomb suit.
The EOD suit is a marvel of engineering, meticulously designed to shield its wearer from the deadliest threats posed by explosive devices. However, this protective ensemble is not just a suit; it’s a complex system that raises intriguing questions about load carriage. How does wearing an EOD suit differ from conventional encumbering personal protective equipment (PPE), such as firefighting PPE? What unique challenges and considerations come into play when responding to explosive threats in this specialized attire?
Previous research has shown that wearing encumbering PPE causes decrements in performance in firefighting PPE (REF), police PPE (REF) and limited research in EOD PPE. Due to the disparity in the amount of research in each of these areas, it is important to investigate how similar and different the demands of wearing this equipment are to inform professionals of the difficulties of wearing this equipment.
Additionally, it is not only the metabolic and physiological demands of the equipment but also the psychological demands that need to be further understood. How difficult the equipment is perceived to be is important for operation. A greater understanding of the demands will only serve to improve the preparation of the operators utilizing the equipment in the field due to appropriate physical and psychological preparation for the use of the equipment.
Physical training programs must be designed to enhance strength and endurance to help EOD personnel perform better with the demands of their equipment.
This investigation delves into the under-researched area of EOD load carriage, drawing comparisons between the distinctive features of EOD suits and conventional encumbering PPE. By exploring the ergonomic, practical and operational disparities, we aim to unravel the intricacies that set EOD suits apart and shed light on the crucial balance between protection and functionality in high-stakes scenarios.
Seventeen healthy, recreationally trained adults (12 men, five women) aged 23±4.8 years, height 1.76±.07 meters, weight 88.5±15.6 kilograms, body fat percentage 20.5±10.1 percent (mean ± SD) were recruited for this randomized crossover study. Recreationally trained in this study is defined as being physically active at least three days per week for at least 30 minutes per session. Participants were free from any musculoskeletal or cardiovascular disorders based on health history questionnaires. Informed consent was obtained from all participants before the commencement of the study (IRB approval No. 4473).
Experimental design
Participants completed four testing sessions, each separated by a minimum of 72 hours and up to 10 days, to minimize the effects of fatigue or changes in fitness levels. The testing battery was in the order listed below. The order of load carriage scenarios was randomized to control for potential learning effects. The load carriage options were firefighting PPE (pants, jacket, SCBA, helmet and gloves — approximately 30 kilograms), police PPE (bulletproof vest and duty belt — approximately 10 kilograms) and EOD PPE (trousers, integrated groin protection, jacket and helmet — approximately 35 kilograms).
Biometric testing
Upon arrival for each visit the subjects would have their resting blood pressure (BP) measured (Omron arm cuff), heart rate (Omron arm cuff), body weight and body composition (Tanita scale 4 point BIA) and Sozo device 8 point BIS (Impedimed). The same tests were performed after the entire physical battery was completed to assess changes in body weight due to the testing.
Testing protocol
The testing protocol went as follows for every visit. The point at which the PPE was put on for the trial was after the isometric rack pull.
- Vertical jump
- Handgrip dynamometer
- Isometric rack pulls
- Bar step over
- Stair sprints
- Sled dragging
- Sprint
- Crawls
- Bruce protocol treadmill testing
After the conclusion of the treadmill testing, the subjects removed the PPE then performed an additional vertical jump, handgrip dynamometer and isometric rack pull test utilizing the previously explained testing methodology. After, they performed another battery of biometric tests of heart rate, BP, body weight and body composition.
Statistical analysis
Descriptive statistics were taken on all subject data and performance data. Ventilatory anaerobic threshold (VAT) was determined as the first time point where the respiratory exchange ratio (RER) value went over 1. Performance data were analyzed using repeated measures analysis of variance (ANOVA) to assess differences in physiological responses and perceived exertion across the various load carriage exercises. Post-hoc tests were conducted to identify specific differences. Statistical significance was set at p < 0.05. Correlations between performance in tasks while wearing the PPE to the subject data and performance data.
- Vertical jump. Overall, there was no change in performance due to wearing the equipment from the pre- to post-testing values on the vertical jump with any of the visits or when compared with one another.
- Hand grip dynamometer. There were no significant differences between any of the visits for changes in handgrip dynamometer strength from pre- to post-testing. The equipment had no significant effect on performance.
- Stair climb. Overall performance in the stair climb significantly decreased in the EOD suit and firefighting gear visits compared with the familiarization. There was no significant difference in the police equipment to the familiarization, however, EOD suits and fire gear were significantly slower than the police equipment.
- Sprint 10 yards. The sprint time was significantly slower in the fire gear and EOD suit visits compared with the initial visit and police gear. The police gear was not significantly slower than the familiarization visit.
- Sled drag. Overall, the bomb suit was significantly slower than the familiarization and the police equipment visits. There were no other significant differences between any of the groups. The responses were the same between the 10-yard split and the 20-yard finish.
- Bear crawl. The bear crawl was significantly slower in the EOD suit than in all other visits. The firefighting gear also was significantly slower than the familiarization. The increase in RPE reflected the same significance as the time to completion for significant differences.
- Belly (Army) crawl. The belly crawl was slower and perceived as harder in the EOD suit visit compared with the familiarization and the police equipment visits. The firefighting gear was harder than the familiarization but it was not significantly slower.
- Treadmill performance. Metabolically, the EOD suit performance was markedly higher in the VO2 compared with the familiarization and the police equipment visit at each three-minute interval. The peak VO2 demand was lower in the police equipment visit because the gear visit trials were not to a maximum. The same results were observed with the RPE and HR. Additionally, the metabolic demands through VO2, HR and RPE were significantly higher in the firefighting gear than in the familiarization visit.
The findings of this study highlight the significant impact that wearing EOD equipment has on physical performance and metabolic demand. The results indicate a clear decline in performance metrics, including reduced endurance and speed, as well as an increased metabolic rate during physical tasks. These outcomes underscore the physiological burden imposed by EOD gear, which has important implications for the health, safety and efficiency of personnel operating in hazardous environments.
These results were similar to the firefighting PPE, whereas the metabolic demands and performance changes in the police gear had little effect on performance compared with control conditions. However, after wearing the equipment, there was no notable fatigue from pretesting performance.
Performance decrements
The data demonstrate that EOD equipment significantly hinders physical performance in a very similar way but to a greater degree than firefighting equipment compared with the other visits. The added weight and bulk of the gear impede movement and reduce speed. It is worth noting that the crawling tasks were the most impacted by wearing the equipment, likely due to the distribution of the weight in the protective equipment compared with the firefighting PPE.
Overall, this is consistent with previous research showing that load carriage negatively affects physical performance by altering biomechanics and increasing the energy cost of movement (Attwells et al., 2006; Knapik et al., 2004). Participants exhibited notable decreases in the variety of movement tests, suggesting that the ergonomic design, though optimized, has an increased weight encumbrance of EOD equipment that significantly affects performance.
Increased metabolic demand
The increased metabolic demand observed in this study aligns with the hypothesis that EOD equipment elevates the physiological strain on the body. Wearing the equipment resulted in higher heart rates, increased oxygen consumption, increased RER and elevated perceived exertion levels during exercise tasks. This heightened metabolic response can be attributed to the additional weight and restricted movement caused by the gear, which requires more energy to perform the same tasks compared to a nonencumbered state (Harman et al., 1999; Roy et al., 2016).
These increases in demands are important to account for not only the physical preparation of those using the equipment but also the fuel source, because the elevated RER and earlier VAT denoting a greater carbohydrate demand for lower intensity work which can cause fatigue at earlier points. This would suggest nutritional strategies should be implemented for longer duration use of the equipment as well as appropriate nutritional timing. How these demands scale based upon body size and lean body mass is also worth investigating further as is how the thermic demands of the equipment affect performance.
Perceptions of operations inside the equipment
Another reoccurring result in our investigation was that the EOD PPE has markedly higher ratings of perceived exertion compared to the other conditions. This is quite possibly due mostly to the novelty of the equipment, however, the firefighting gear was denoted as being more difficult than the other conditions. Further investigations should examine whether there is a learning effect of wearing the equipment over time.
Implications for operational performance and safety
The combined effect of decreased performance and increased metabolic demand poses significant challenges for EOD personnel. Reduced physical performance can compromise task efficiency and precision, which are critical in EOD operations where meticulous attention to detail and rapid, precise movements are essential. Moreover, the increased metabolic cost might lead to a quicker onset of fatigue, reducing the operational duration and increasing the risk of heat-related illnesses and other health issues (Cheung & McLellan, 1998).
Given the similarities of the decrements in performance in the EOD equipment to the firefighting equipment, individual tasks with physical preparation of EOD personnel should draw from the literature on training firefighters to develop their ability to perform in their equipment.
Recommendations for training
Due to the obvious increase in demands from wearing this equipment in high-stress situations, specific physical training programs must be designed to enhance strength and endurance to help EOD personnel perform better with the demands of their equipment. Tailored conditioning programs that simulate operational conditions may improve overall performance and resilience (Nindl et al., 2013). Future investigations should examine whether wearing the equipment when performing dual tasks can further impact performance and how the dual-task performance decrement relates to the metabolic fitness of the individual.
In conclusion, the study clearly illustrates that wearing EOD equipment results in significant decreases in physical performance and increases in metabolic demand. These findings have critical implications for the design of protective gear and the training of EOD personnel. By addressing the ergonomic and physiological challenges posed by EOD equipment, it is possible to enhance the safety, efficiency and effectiveness of those engaged in high-stakes operations. Continued research and development in this field are essential to support the well-being and operational capability of EOD professionals.
Contact Mike Lane at Michael.Lane@eku.edu.
