Development of role-related minimum cardiorespiratory fitness standards for firefighters and commanders

Association of Physical and Emotional Parameters with Performance of Firefighters: A Systematic Review

Firefighting requires a high level of physical fitness and causes substantial psychological stress, engendering musculoskeletal, mental, and cardiac issues. Consequently, it is necessary to measure the preparation of the firefighters daily through the Firefighting Physical Ability Tests (FPATs). According to the literature, some variables are more important for performance in the FPAT. Therefore, we aimed to summarize evidence that relates physical and mental aspects to the FPAT performance. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) method, screening 1055 records from databases and selecting 15 that met inclusion criteria. No emotional and psychological variables were correlated with the FPAT. Most research shows significant correlations between the FPAT performance and the following: aerobic fitness, upper body endurance and strength, anaerobic capacity, body fat, and age. Lower body endurance and strength, as well as anaerobic power, had a low number of investigations and need to be further explored. Abdominal endurance showed weak correlations, while flexibility did not show any correlations in most studies, although these should be considered for injury prevention. We recommend that fitness programs and evaluations include a global analysis considering the evidence presented for methodological improvements.

Effect of Cardiorespiratory Fitness Level on Physiological Responses and Task Performance During a High-Rise Firefighting Task

OBJECTIVES

To determine the impact of cardiorespiratory fitness (CRF) on physiological and performance outcomes during a 120-m vertical high-rise ascent in firefighters with CRF levels at or above (higher-fit) and below (lower-fit [LF]) the national recommended minimum physical employment standard (V˙O 2 max 42.3 mL·kg -1 ·min -1 ).

METHODS

Twenty-eight firefighters completed two high-rise firefighting trials (continuous and discontinuous ascent with predetermined 1-minute rest breaks). Task time, heart rate, ratings of perceived exertion, core body temperature, and thermal comfort were recorded at predetermined elevations.

RESULTS

Task time was significantly longer in both trials for the LF group. Ratings of perceived exertion and thermal comfort were also significantly higher in the LF group, with three times more LF firefighters being unable to complete the ascent without sounding their low-air alarm.

CONCLUSIONS

Higher CRF improves performance and efficiency during stair-climbing in simulated high-rise firefighting tasks.

Skeletal muscle fitness and physiology as determinants of firefighter performance and safety: a narrative review

Firefighters routinely perform tasks that are reliant on their muscular fitness, which includes muscular strength, power and endurance. Separately, firefighters can present with unique skeletal muscle physiology characteristics due to the strenuous nature of this occupation. This review aims to summarise muscular fitness and physiology as determinants of a firefighter's ability to perform occupation-specific tasks, identify the relevance of both muscular fitness and physiology to a firefighter's risk for sustaining a work-related injury, and address the contributions of muscular fitness and physiology on a firefighter's ability to recover from tasks and their readiness for performing subsequent or future tasks. The presented evidence reveals muscular fitness can determine a firefighter's capacity to perform their job effectively, while also influencing risk for occupational injury. Collectively, this review indicates exercise training emphasising improvements in muscular strength, power, and endurance (i.e. resistance training) should be encouraged in this occupation.

Validity of submaximal aerobic capacity and strength tests in firefighters

BACKGROUND

Typically, the fitness of UK firefighters is assessed via submaximal estimate methods due to the low demands on time, money, expertise and equipment. However, the firefighter-specific validity of such testing in relation to maximum aerobic capacity (V˙O2max) and particularly muscular strength is not well established.

AIMS

To examine the validity of submaximal methods to estimate V˙O2max and maximal strength in operational firefighters.

METHODS

Twenty-two full-time operational firefighters (3 female) completed same-day submaximal (Chester Step Test; CST) and maximal (treadmill) assessments of V˙O2max, with a sub-sample of 10 firefighters (1 female) also completing submaximal and maximal back-squat (i.e. one repetition maximum; 1RM) assessments. All participants then completed the Firefighter Simulation Test (FFST) within 2-4 days.

RESULTS

CST underestimated actual V˙O2max by 1.4 ml·kg-1·min-1 (~3%), although V˙O2max values were positively correlated (r = 0.61, P < 0.01) and not significantly different. Estimated V˙O2max values negatively correlated with FFST performance (r = -0.42). Predicted 1RM underestimated actual 1RM by ~2%, although these values were significantly correlated (r = 0.99, P < 0.001) and did not significantly differ. The strongest predictive model of FFST performance included age, body mass index, and direct maximal measures of 1RM and V˙O2max.

CONCLUSIONS

Submaximal back-squat testing offers good validity in estimating maximum firefighter strength without exposure to the fatigue associated with maximal methods. The CST provides a reasonably valid and cost-effective V˙O2max estimate which translates to firefighting task performance, although the error observed means it should be used cautiously when making operational decisions related to V˙O2max benchmarks.

Physiological Responses and Performance of Simulated High-Rise Firefighting

OBJECTIVE

The aim of the study is to determine the physiological effects of breathing apparatus and ascent strategies during a simulated 120-m vertical high-rise firefighting ascent.

METHODS

Twenty-eight firefighters completed four high-rise firefighting trials wearing standard- or extended-duration breathing apparatus with continuous ascent (SDBA-C/EDBA-C) or with breaks (SDBA-B/EDBA-B). Task time, heart rate, ratings of perceived exertion, core body temperature, and thermal comfort were recorded at predetermined elevations.

RESULTS

Task time took significantly longer during the EDBA-C compared with SDBA-C trial. Heart rate (at 40, 80, and 100 m) was significantly lower in trials following breaks compared with the continuous trials. Core body temperature rose by 0.11°C every 10 m of ascent. During the SDBA trials, 89% to 96% of firefighters activated their low air alarm compared with only 7% in EDBA.

CONCLUSIONS

Firefighters should wear EDBA beyond 80 m of ascent and are encouraged to take regular breaks.

Identifying the most important, frequent, and physically demanding tasks of Brazilian firefighters

This study aimed to identify the most important, frequently performed, and physically demanding tasks performed by Brazilian firefighters and to identify tasks that could be used to assess physical fitness. A subjective task analysis was conducted. Five hundred twenty-four firefighters (84% male; 16% females) responded to an online survey and rated 37 tasks across three domains (most important, most frequent, and most physically demanding). A dichotomous decision analysis was used to inform the proposed physical fitness tests. Wildland firefighting tasks presented the highest overall mean rate. Traffic control was considered the most important and frequently performed task. Lifeguard rescue was considered the most physically demanding task. The dichotomous analysis identified 14 essential tasks (seven structural firefighting and seven automobile accidents). The tasks identified may be helpful in developing criterion physical fitness tests and training programs related to firefighters' demands.Practitioner summary: The unpredictability, variability, and dangerousness of firefighting make it challenging to observe the physical demands imposed on firefighters. A subjective task analysis was conducted to identify essential tasks performed by Brazilian firefighters. Wildland firefighting, lifeguard rescue, automobile accidents, and structural firefighting tasks were the most important, frequent, and physically demanding.

Physiological demands and physical performance determinants of a new firefighting simulation test

The study aimed to examine physiological responses of firefighters performing a firefighting simulation test (FST) and to determine the relationship between physical fitness parameters and FST performance. Aerobic fitness, muscular strength, muscular endurance, and anaerobic capabilities were evaluated in 37 firefighters (21-profesionals and 16-volunteers firefighters). Furthermore, participants carried out the FST during which we measured performance, respiratory gas exchange, heart rate (HR), perceived exertion and blood lactate concentrations. Males were significantly faster than females for all tasks of the FST (p < 0.01); however, final performance score (16.5 ± 2.9 and 14.5 ± 2.6 points for males and females, respectively), HR (94.0 ± 2.0% and 93.7 ± 2.3% of HRmax) and perceived exertion (8.1 ± 0.9 and 7.1 ± 1.3) were not significantly different. Prediction of FST performance by LASSO regression revealed a model that included mainly aerobic capacity and maximal strength. In conclusion, FST challenged both aerobic and anaerobic energy metabolisms for both males and females and requires various physiological abilities to perform. Practitioner Summary: For the safety of firefighters and victims, firefighters must meet minimum physical requirements. 37 firefighters performed physical tests and a new firefighting test implemented for the recruitment of firefighters in France. The results revealed that this test is strenuous and that performance is associated with cardiorespiratory fitness and muscular strength. Abbreviations: V̇O2: oxygen consumption; V̇CO2: carbon dioxyde production; V̇E: expired ventilation; RER: respiratory exchange ratio; FST: firefighting simulation test; MAS: maximal aerobic speed; HR: heart rate; RPE: rating of perceived exertion; MVC: maximum voluntary contraction; IMTP: isometric mid-thigh pull; TTE: time to exhaustion; Ppeak: peak power; Pmean: mean power; LASSO: least absolute shrinkage and selection operator; La-: blood lactate concentration.

Impact of fire protective equipment and the self-contained breathing apparatus on peak exercise in males and females

With an increase in the number of females entering the fire service it is important to understand the potential impact of personal protective equipment (PPE) on females. This study compared selected physiological responses during two graded exercise tests (GXT) performed in a counterbalanced design: GXTPT - wearing athletic clothing while breathing through a low-resistance valve; and GXTPPE - wearing PPE and breathing from a self-contained breathing apparatus (SCBA). Sixteen males and 15 females acted as participants. V ˙ O2peak was significantly lower, by approximately 15%, during the GXTPPE compared to the GXTPT condition for both the males and females. Physiologically, the decreased oxygen consumption was strongly related to an attenuated ventilation (r = 0.75 and 0.71) and oxygen pulse (r = 0.94 and 0.93) for the males and females, respectively. The results of this investigation demonstrate that the SCBA and PPE impacts males and females to a similar relative extent and manner. Practitioner summary: Little information exists regarding the impact of the SCBA and PPE on physiological parameters for females. This investigation determined that females have reduced exercise capacities to the same extent as males, which should be considered when evaluating the aerobic demands of fire suppression work and the fitness levels of firefighters.Abbreviations: GXT: graded exercise test; SCBA: self-contained breathing apparatus; personal protective equipment; MMC: metabolic measurement cart; ANOVA: analysis of variance; RPE: rating of percieved exertion; PRD: perceptions of respiratory distress; PTD: percieved thermal distress; V ˙ O2: rate of oxygen consumption; V ˙ O2peak: rate of oxygen consumption at peak exercise; V ˙ Epeak: minute ventilation at peak exercise; V ˙ E/V ˙ CO2: ventilatory equivalent for carbon dioxide; FVC: forced vital capacity; FEV1: forced expiratory volume in one second; FEF25-75%: forced expiratory flow; PEF: peak expiratory flow rate; MVV: maximum voluntary ventilation.

Designing criterion measures for physically demanding jobs

The Bureau of Labor Statistics reported that 39.1% of the civilian workforce in the United States performs physically demanding jobs that require lifting, carrying, pushing/pulling, kneeling, stooping, crawling, and climbing activities in varied environmental conditions. United States military occupations are similar to those in the civilian sector involving equipment installation, emergency rescues, and maintenance, along with combat arms occupations. This article provides an overview of the types of criterion measures used to assess the physical domain and approaches for designing and evaluating the criteria. It also includes a method for generating criterion measures that are applicable across multiple jobs.

Blood Pressure Responses in Firefighters: A Review

Blood pressure (BP) responses are controlled by various factors and understanding how BP changes is important to occupational health. This paper presents a review of the literature that reports BP responses in the firefighter population. Hypertension is one of the main risk factors underlying the pathophysiology of cardiovascular disease (CVD), and cardiac incidents remain the leading cause of line-of-duty deaths in firefighters. Risk factors for line-of-duty deaths include obesity, previous or underlying heart disease, and hypertension. The occupation of firefighting is one of the most hazardous and dangerous jobs, yet over 50 % of firefighters are volunteers. Tactical operations and the hazardous nature of firefighting are exposures that influence stress responses and, therefore, affect BP. In fact, hypertension in firefighters often remains undocumented or undiagnosed. CVD risk and elevated BP in tactical populations, like firefighters, maybe a combination of physical and emotional stress due to the nature of the job. Cross-sectional studies have reported that firefighters have higher levels of BP and higher rates of hypertension compared to civilians. Interestingly, there is a limited amount of research that reports BP values before and after firefighting- related activities, and very few studies on interventional changes in BP. Here, we synthesize the literature on firefighting and provide a summary of the studies that report pre- and post- BP levels that relate to CVD risk factors, occupational factors, firefighting activities, and the data on exercise training and BP. More studies are needed that examine BP in firefighters and report on the changes in BP with occupational activities.

The Validity and Reliability of a Treadmill Test for Structural Firefighter Applicants

OBJECTIVE

This 2-part study evaluated validity and reliability of a treadmill test for structural firefighters.

METHODS

Wearing fire protective ensemble, 260 participants walked at 1.56 m·s-1, completing a 5-min warm-up, an 8-min stage at a 5.71° incline, then graded stages to exhaustion. In Part 2, 21 participants completed the test on 3 separate days under standardized conditions.

RESULTS

Average (±SD) oxygen uptake () during minutes 1-13 was similar to reported values for simulated fire-rescue work. During the 13th min, was consistent with recommendations for firefighters. in Part 2, exercise duration increased between trials 1 and 2 before stabilizing but was consistent.

CONCLUSIONS

Congruence with reported during simulated firefighting and recommendations for confirmed validity. Acceptable test-retest reliability was demonstrated. We conclude that the test is valid and reliable for evaluating cardiorespiratory endurance for firefighting.

Evidence for Validity and Reliability, and Development of Performance Standards and Cut-Scores for Job-Related Tests of Physical Aptitude for Structural Firefighters

OBJECTIVE

This multi-part study aimed to revise an existing battery of physical aptitude tests for firefighter applicants. Test validity and reliability were evaluated and performance thresholds were determined.

METHODS

In Part I, 49 structural firefighters rated the similarity between the physical demands of the tests and corresponding work activities. In Part II, 23 participants completed the tests on 3 separate days. In Part III, cut-scores were determined using the Bookmark method by an expert panel of 25 firefighter supervisors.

RESULTS

Analysis revealed high levels of validity and reliability. The expert panel provided invaluable direction through a combination of independent and group work, leading to consensus on acceptable completion times.

CONCLUSION

Rigorous processes established scientific credibility for the revised battery of tests. Expert knowledge from firefighter supervisors contributed to determining cut-scores following established scientific methods.

Development of muscle mass and body fat reference curves for white male UK firefighters

OBJECTIVE

This study describes the development of the world's first suite of firefighter body composition centile reference curves which can be used as both academic research tools and clinical references, to plot and track individual firefighter skeletal muscle mass (SMM) and fat mass (FM) measurements against the representative reference sample.

METHODS

The body composition of 497 white male London (England) firefighters was measured by anthropometry and bioelectrical impedance analysis. Smoothed centile curves were then generated for skeletal muscle mass index (SMMI), fat mass index (FMI), body fat percentage (BF%) and waist-to-height ratio (WHtR).

RESULTS

Between 48 and 62 years, firefighter SMMI is greater than the UK white male age-matched general population by a mean of 0.35 units, although SMMI declines 0.006 units/years faster in firefighters between these ages. This is estimated to translate to a mean decline of approximately 0.6% of absolute SMM per year. Between 40 and 49 years, firefighter FMI is 0.1 units greater than the UK white male age-matched general population, which becomes identical (7 units) between 50 and 54 years. At the 50th centile, WHtR exceeds 0.5 by 39 years reaching 0.55 at 62 years. This contrasts with FMI which remains stable from 47 years.

CONCLUSION

Firefighters in this study possess greater FM and SMM compared with the UK general population. SMM appears to decline rapidly within older age ranges. These references offer a novel improvement upon the limitations of BMI and BF% for the benefit of an occupational group at elevated risk of cardiovascular disease.

Comparison of swimming versus running maximal aerobic capacity in helicopter rescue paramedics

Swimming is a critical task for helicopter rescue paramedics and aerobic capacity is assessed in this occupation to determine job suitability. We evaluated one treadmill-based and one pool-based assessment of maximal aerobic capacity (V̇O_2peak) in 14 helicopter rescue paramedics. There was a small absolute difference (p = 0.11, d = 0.46) between V̇O_2peak in the swim (45.5 ± 7.8 ml.kg^-1.min^-1) compared to the run (48.5 ± 5.5 ml.kg^-1.min^-1), with a moderate relationship noted (r = 0.74, 95% CI [0.35-, 0.91], p = 0.0023). Whilst not interchangeable, run V̇O_2peak was a predictor of swim V̇O_2peak. Maximal blood lactate was similar (p = 0.93) in swim (13.4 ± 3.8 mmol.L^-1) and run (12.2 ± 3.0 mmol.L^-1), and maximal heart rate 13% lower (p < 0.0001) in the swim (162 ± 11 bpm) versus the run (186 ± 10 bpm). To estimate swimming V̇O_2peak in paramedics a treadmill test is sufficient but does not replace assessment of swimming proficiency. Practitioner Summary: We developed a swim protocol to assess maximal aerobic capacity in helicopter rescue paramedics. Compared to a treadmill-based test, our swim protocol generated 20% lower submaximal V̇O₂ and 6% lower V̇O_2peak. Although not interchangeable, a treadmill V̇O_2peak test is indicative of maximal aerobic capacity in rescue paramedics whilst swimming. Abbreviations: HEMS: helicopter emergency medical service; PES: physical employment standards; ICFP: intensive care flight paramedic; RPE: rating of perceived exertion.

Preventing and Monitoring Work-Related Diseases in Firefighters: A Literature Review on Sensor-Based Systems and Future Perspectives in Robotic Devices

In recent years, the necessity to prevent work-related diseases has led to the use of sensor-based systems to measure important features during working activities. This topic achieved great popularity especially in hazardous and demanding activities such as those required of firefighters. Among feasible sensor systems, wearable sensors revealed their advantages in terms of possibility to conduct measures in real conditions and without influencing the movements of workers. In addition, the advent of robotics can be also exploited in order to reduce work-related disorders. The present literature review aims at providing an overview of sensor-based systems used to monitor physiological and physical parameters in firefighters during real activities, as well as to offer ideas for understanding the potentialities of exoskeletons and assistive devices.

Consensus on tasks to be included in a return to work assessment for a UK firefighter following an injury: an online Delphi study

OBJECTIVE

The aim was to provide a consensus tasks needed to be included in a return to work assessment for operational firefighters.

METHODS

A two round online Delphi study was conducted with twenty-four participants including firefighters, service fitness advisers and occupational health managers. A consensus was set at 70% agreement. In round one, participants completed an online survey relating to tasks to be included during a return to work assessment for firefighters following an injury. Round two was an online consensus meeting to discuss the tasks where consensus was not achieved.

RESULTS

A consensus was reached for ten of the thirteen tasks, including the number of repetitions required when lifting a light portable pump and climbing a ladder. A consensus was reached for the total distance equipment which should be carried. This included carrying a ladder, a hose and a light portable pump.

CONCLUSIONS

This study has provided a consensus for tasks to be included when assessing a firefighter for return to work. Further research is needed to understand how to use this assessment optimally.

Psychosocial barriers and facilitators for a successful return to work following injury within firefighters

Objective

The aim was to explore firefighter’s experiences during their recovery from injury. Focused specifically on exploring perceived psychosocial barriers and facilitators firefighters faced during recovery and return to work.

Methods

Semi-structured interviews were used to provide an in-depth understanding of the firefighter’s experiences. The semi-structured interviews were informed by a topic guide. The topic guide focused on five main themes, (1) overall experience of returning to operational duties following an injury, (2) perceived barriers experienced during their return to work, (3) perceived facilitators experienced during their return to work, (4) confidence in participating in physical activity following injury and (5) where they felt areas of improvement could be made with the return to work process. Thematic analysis of the data collected was undertaken using The Framework Method.

Results

Two main themes were sought after transcription: barriers and facilitators. From these, nine subthemes were identified (1) communication, (2) confidence in physical activity participation, (3) modified duties, (4) physiotherapy, (5) return to operational duties, (6) support, (7) inconsistency, (8) use of station gyms, (9) detachment from the watch.

Conclusions

Consideration should be made for the consistency of procedures followed during an individual’s return to work following an injury. Further research is needed to understand if the themes identified in this study are the same for other fire services. Further research is also needed to understand how the findings may be best implemented within the fire service.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00420-021-01712-z.

Cardiorespiratory Fitness in Spanish Firefighters: Age Differences and Associations Between Fitness-Related Parameters

OBJECTIVE

To evaluate the cardiorespiratory fitness and other fitness-related measures, and to analyze the differences among age groups.

METHODS

This study was conducted on 104 firefighters. Maximal oxygen uptake (VO2 max) was assessed using the Shuttle Test and fitness was evaluated using appropriate physical tests.

RESULTS

Mean VO2 max was 45.7 mL/kg/min and 60.6% of firefighters were over the minimum accepted standpoint to do effective work, however, the VO2 max decreased with increasing age. 35.6% of the firefighters were overweight. Age, weight, and total body fat were found to be significant predictors of VO2 max level in this population, with total body fat as strongest predictor.

CONCLUSIONS

Healthy habits-based interventions tailored by age groups should be promoted, to improve cardiorespiratory fitness and body composition for safe work and to improve firefighters' health.

Physical Fitness Evaluation of Career Urban and Wildland Firefighters

OBJECTIVE

Examine the physical fitness of career firefighters and compare their results to normative data and suggested standards for their profession.

METHODS

Eighty firefighters completed a body composition analysis, maximal aerobic capacity (VO2max) test, and fitness testing battery, with results compared with normative value tables. Maximal aerobic capacity was correlated to fitness measures and differences between VO2max quartiles were examined.

RESULTS

Twenty-two firefighters met the suggested standard for VO2max. Seventy percent of participants were classified as overweight or obese based on body mass index, while 25% were classified as having either "poor" or "very poor" body fat levels. Firefighters were above average for muscular strength.

CONCLUSION

The firefighters had low aerobic fitness and higher than optimal body fat levels. Training programs may be necessary to assist firefighters in achieving optimal fitness levels.

Review of methods to identify the critical job-tasks undertaken by the emergency services

BACKGROUND:

The roles of the emergency services are challenging and often physically demanding. Readiness to meet these challenges and demands is a fundamental requirement for staff to deliver their roles safely and effectively. Furthermore, employers are required by law to demonstrate every reasonable effort to protect their staff from undue risk of work-related injury. Implementing Physical Employment Standards (PES) enables employers to assign staff to roles for which they are physically-suited whilst contributing to such duty-of-care. However, for PES to be successful and legally-defendable, standards must reflect the demands of those job-tasks which are truly critical to the readiness of these services.

OBJECTIVE:

To determine whether a standardised approach to identifying critical job-tasks exists in the development of PES for the emergency services.

METHODS:

Studies which conducted analysis of job-tasks to develop PES within the emergency services were reviewed.

RESULTS:

Forty-two reported studies (i.e. records) met the inclusion criteria. Methods to determine job-tasks varied but were typically criteria-based incorporating one, or all, of 9 reported techniques. Methods were subjective and based upon reference to past or present job-task performance.

CONCLUSION:

Correctly determining critical job-tasks is essential for effective, legally-defendable PES. A standardised method to define job-tasks remains to be established.

Cardiovascular and Psychophysical Response to Repetitive Lifting Tasks in Women

Background

Understanding the cardiovascular and psychophysical demands of repetitive lifting tasks is important in job design strategies. This study determined the cardiovascular (oxygen consumption (VO₂) and heart rate (HR) and psychophysical response to repetitive lifting tasks in women.

Methods

Ten female (age 27 ± 5 yrs) participants transferred 11.4, 15.9, and 20.5 kg weights back and forth from a rung 40.6 cm high to a rung 156.2 cm high. Rungs were 195.6 cm apart horizontally. Three, 10 minute bouts (1 = 11.4 kg; 2 = 15.9 kg; 3 = 20.5 kg) were performed at 6 lifts per minute. Cardiovascular and psychophysical (rating of perceived exertion, RPE) parameters were monitored throughout the bouts. VO₂max and HRmax were determined via a maximal treadmill test.

Results

VO₂, HR, and RPE were significantly different between each work bout (p < 0.01), with each outcome variable increasing as load increased. VO₂max and HRmax equaled 46.5 ± 7.5 mL·kg⁻¹·min⁻¹ and 191 ± 11 bpm, respectively. Work at 11.4 kg was performed at 38% VO₂max and 63% HRmax; at 15.9 kg at 41% VO₂max and 72% HRmax; and at 20.5 kg at 49% VO₂max and 81% HRmax. RPE at 11.4, 15.9, and 20.5 kgs were: 8.4 ± 1.6, 11.4 ± 1.9, and 15.0 ± 2.2.

Conclusion

During these repetitive lifting tasks, metabolic cost and perceived exertion increased with weight lifted; average work intensity ranged from 63 to 81% of HRmax and 38 to 49% of VO₂max. Results have important implications in relation to job pacing and design, and worksite health promotion strategies aimed at reducing work place injury.

Physical Employment Standards for UK Royal Navy Personnel: A Survey of Tasks That Require Muscle Strength and Endurance

INTRODUCTION

Physical Employment Standards (PES) safeguard the requirement to create a suitable job-person fit in military occupations, and in doing so mitigate some operational and musculoskeletal injury risk. The primary purpose of this research was to identify critical - physically demanding tasks performed by UK Royal Navy (RN) seafarers to inform the development of a muscle strength and endurance-based PES. A secondary purpose was to explore possible sex and age-based differences in subjective ratings of occupational task physical demand.

MATERIALS AND METHODS

In accordance with the Ministry of Defence Research Ethics Committee, 515 Naval personnel (443 males, 72 females; aged 30.2 ± 7.3 years) completed an anonymous survey that rated the physical demand (from no to very high), criticality (from not to critically important), and frequency (from seldom to several times per day) of 25 common sea-going tasks on a one to five scale. An a priori criteria was applied to down-select a shortlist of the most critical and physically demanding tasks (i.e., median task criticality and task physical demand scores of ≥4, and ≥3, respectively). A Mann-Whitney and Kruskal-Wallis test explored sex and age-based differences in subjective physical demand ratings.

RESULTS

Ten (out of 25) tasks met the critical - physical demand criteria, which included the four task categories of fire fighting, damage control, casualty handling, and basic movement/transit tasks. Casualty handling emerged as the single most physically demanding task category performed by seafarers, which was rated to have "high" physical demand (4 on the 1 to 5 scale). Sex and age-based differences in subjective ratings of task physical demand were equivocal, with females rating 3 (out of the 25 tasks), and 40-51 year olds rating 4 (out of 25 tasks) to have a higher physical demand than males and 19-29 year olds, respectively.

CONCLUSION

Ten criterion tasks were identified and should undergo a further job analysis to inform the development of strength-based PES for the RN.

Physical and Physiological Performance Determinants of a Firefighting Simulation Test

OBJECTIVE

To examine determinants of firefighting simulation test performance.

METHODS

Sixty-eight (63 male; 5 female) firefighters completed a firefighting simulation (eg, equipment carry, casualty evacuation) previously validated to test occupational fitness among UK firefighters. Multiple linear regression methods were used to determine physiological and physical attributes that best predicted completion time.

RESULTS

Mean (±SD) time taken to complete the simulation was 610 (±79) seconds. The prediction model combining absolute cardiorespiratory capacity (L min) and fat mass explained the greatest variance in performance and elicited the least random error (R = 0.765, R = 0.585, standard error of the estimate [SEE]: ±52 seconds). Higher fitness and lower fat mass were associated with faster performance.

CONCLUSIONS

Firefighter simulation test performance is associated with absolute cardiorespiratory fitness and fat mass. Fitter and leaner individuals perform the task more quickly. Work-based interventions should enhance these attributes to promote safe and effective operational performance.

Identifying Physically Demanding Tasks Performed by the Royal Australian Navy for the Development of a Physical Employment Standard

OBJECTIVE

The aim of this study was to determine an appropriate method to characterize Royal Australian Navy intermittent intensity tasks.

METHOD

Sixteen personnel performed four scenarios: (1) storing: repeatedly handle a 10 to 15 kg crate; (2) firefighting: walk 45 m wearing protective equipment and fighting a fire; (3) and (4) toxic hazard response: casualty evacuation tasks wearing protective equipment. Heart rate and oxygen consumption ((Equation is included in full-text article.)) were measured continuously. Mean and peak values and time spent in incremental zones were calculated.

RESULTS

Scenario 2 elicited the highest oxygen cost (18.1 L, mean (Equation is included in full-text article.)1.5 L.min, time >2.5 L.min: 0.8%), yet scenario 4 elicited the highest mean (Equation is included in full-text article.)(1.8 L.min, oxygen cost 14.4 L), and participants spent a greater duration >2.5 L.min(Equation is included in full-text article.)(23.3% or 1 minute 55 seconds).

CONCLUSIONS

A small difference (0.3 L.min) was observed between scenarios 2 and 4 for mean (Equation is included in full-text article.), yet (Equation is included in full-text article.)>2.5 L.min demonstrated scenario 4 had a higher metabolic demand.

The influence of cardiometabolic risk factors on cardiorespiratory fitness in volunteer Chilean firefighters

OBJECTIVES

Maximum oxygen consumption (VO2_max ) plays a fundamental role in firefighters' occupational activities due to the high intensity tasks they perform in their professional duties. In Chile, firefighters are volunteers (non-salary) and their lack of continuous and programmed physical activity may affect their physical fitness and health. The goal of this study was to determine the influence of anthropometric parameters and cardiometabolic risk (CMR) factors on the cardiorespiratory fitness (CRF) of volunteer Chilean firefighters.

METHODS

Seventy-six volunteer male firefighters (median [5-95 percentiles]) aged 27.5 years [26-56], body mass index (BMI) 27.7 kg m^-2 [19.9-35], and VO2_max 44 mL kg^-1 min^-1 [36-56]) participated in the study. The following variables were assessed: BMI, fat mass%, body density, waist circumference (WC), waist-to-hip ratio (WHR), blood pressure, blood glucose, and VO2_max .

RESULTS

In total, 68% of the samples were overweight or obese. A total of 36% presented abdominal obesity (WC ≥102 cm). High blood pressure (HBP) was observed in 25% of firefighters and high blood glucose was found in about 20%. The presence of abdominal obesity was the strongest predictor of VO2_max (OR = 12.35, 95% CI = 3.56-42.82, P < .001), followed by the WHR (OR = 11.5, 95% CI = 3.1-42.7, P < .001) and high blood glucose (OR = 2.87, 95% CI = 1.7-7.3, P = 0.019).

CONCLUSION

This study showed that abdominal obesity in firefighters was the strongest predictor of low CRF. In addition, CRF was associated with CMR factors, except for HBP.

Physiological, cognitive and neuromuscular effects of heat exposure on firefighters after a live training scenario

This study investigated physiological, cognitive and neuromuscular performances in firefighters after a structural live-fire scenario. Changes in vital signs, environmental parameters and cognitive and neuromuscular performance were measured before and after a live-fire training session in a closed environment, in conditions similar to those one could encounter in a structural fire. Very high ambient temperature peaks were reached during the 30-min sessions. After the session, the forehead temperature was increased by 0.5 °C, mean water body loss was 639 ml and the mean heart rate increase was 7.5 bpm. Mental calculation speed did not vary significantly, however we observed a reduction in reaction time. These findings demonstrated that after 30 min of exposure, heat stress had little impact on firemen. Stress activation seems beneficial after firefighting operations. Normal vital parameters should allow re-engagement for a second firefighting task. This result must be compared with longer exposures.

Lifestyle behaviours and perceived well-being in different fire service roles

Background

Aspects of the work environment influence employee well-being. However, it is unclear how employee lifestyle behaviours, health characteristics and well-being may differ within a broader occupational sector.

Aims

To investigate the health characteristics, lifestyle behaviours and well-being of three Fire and Rescue Service (FRS) occupational groups that differ in shift work and occupational demands: operational firefighters (FF), emergency control (EC) and administrative support (AS) workers.

Methods

Data were obtained via an online survey using previously validated questionnaires to assess health characteristics, lifestyle behaviours and perceived well-being. Differences between groups were explored, controlling for confounding variables, using analysis of covariance (ANCOVA) methods. Effect sizes are reported where appropriate to demonstrate clinical significance.

Results

Four thousand five hundred and sixty-four FRS personnel volunteered, with 3333 (73%) completing the survey out of a total workforce of 60000 (8%). FF reported the lowest prevalence of chronic medical conditions (10%), compared with AS (21%) and EC (19%) workers. Total physical activity (PA) was 66% higher among FF compared with EC and AS workers. Components of sleep and self-rated health were independent predictors of well-being irrespective of FRS role.

Conclusions

FF reported the highest levels of PA and highest perceptions of well-being, and the lowest prevalence of obesity and chronic medical conditions, compared with other FRS occupational groups. These findings may be used to inform FRS workplace intervention strategies.

Physical Employment Standards for UK Firefighters: Minimum Muscular Strength and Endurance Requirements

Objective:

The aim of this study was to assess sensitivity and specificity of surrogate physical ability tests as predictors of criterion firefighting task performance and to identify corresponding minimum muscular strength and endurance standards.

Methods:

Fifty-one (26 male; 25 female) participants completed three criterion tasks (ladder lift, ladder lower, ladder extension) and three corresponding surrogate tests [one-repetition maximum (1RM) seated shoulder press; 1RM seated rope pull-down; repeated 28 kg seated rope pull-down]. Surrogate test standards were calculated that best identified individuals who passed (sensitivity; true positives) and failed (specificity; true negatives) criterion tasks.

Results:

Best sensitivity/specificity achieved were 1.00/1.00 for a 35 kg seated shoulder press, 0.79/0.92 for a 60 kg rope pull-down, and 0.83/0.93 for 23 repetitions of the 28 kg rope pull-down.

Conclusions:

These standards represent performance on surrogate tests commensurate with minimum acceptable performance of essential strength-based occupational tasks in UK firefighters.

Physiological Responses to Firefighting in Extreme Temperatures Do Not Compare to Firefighting in Temperate Conditions

Purpose: The aim of this study was to examine physiological responses to two different simulated firefighting exercises: a firefighting exercise with flashovers, smoke, poor visibility and extreme temperatures (300°) in a burning container and a standard firefighting exercise in temperate conditions. Furthermore, a second purpose of the study was to find out if the contribution of strength and endurance capacities to firefighting performance changes when the demands of the firefighting exercise change.

Methods: Sixteen professional firefighters performed a maximum treadmill test, strength testing, a standard simulated firefighting exercise (SFE) without heat and flashovers and a firefighting exercise with a simulation of the flashover phenomenon in a burning container (FOT). The treadmill testing was used to determine peak oxygen uptake (VO_2peak), ventilatory threshold (VT1) and respiratory compensation point (RCP). Three intensity zones were identified according to heart rate (HR) values corresponding to VT1 and RCP: zone 1–HR below VT1, zone 2-HR between VT1 and RCP, zone 3–HR above RCP. Firefighting performance was determined by a simple time-strain-air depletion model (TSA) taking the sum of z-transformed parameters of time to finish the exercise, strain in terms of mean heart rate, and air depletion from the breathing apparatus. Correlations were then established between TSA based firefighting performance parameters and fitness variables representing strength and endurance.

Results: HR was significantly lower during SFE (79.9 ± 6.9%HR_max) compared to FOT (85.4 ± 5.2%HR_max). During SFE subjects spent 24.6 ± 30.2% of time in zone 1, 65.8 ± 28.1% in zone 2 and 9.7 ± 16.6% in zone 3. During FOT subjects spent 16.3 ± 12.8% in zone 1, 50.4 ± 13.2% in zone 2 and 33.3 ± 16.6% in zone 3. Out of all correlations, relative VO_2peak showed the highest relation to mean HR during SFE (−0.593) as well as FOT (−0.693).

Conclusions: Endurance in terms of VO_2peak is an important prerequisite for both firefighting exercises. However, for standard simulated firefighting exercises it is important to work below VT1. For firefighting exercises in extreme temperatures with smoke, poor visibility and unexpected flashovers a high fitness level is required in order to keep the time spent above RCP as short as possible.