Male Firefighters Research Articles

The effect of twelve weeks of high-intensity functional training and Ginkgo biloba consumption on the serum levels of some inflammatory cytokines in operational male firefighters of Yazd city

Introduction: functional exercises and consumption of the medicinal plant Ginkgo biloba, a natural source of flavonoids and polyphenolic compounds, have beneficial effects in improving the inflammatory state and physical performance of people exposed to occupational stress. Therefore, the aim of the present study was to investigate the effect of 12 weeks of high-intensity functional training and consumption of Ginkgo biloba extract on the serum levels of interleukin-8 and interleukin-1β in operational male firefighters of Yazd city. Materials and Methods: For this purpose, 48 male firefighters were randomly divided into four groups including high-intensity functional training (HIFT), high-intensity functional training with ginkgo biloba consumption, ginkgo biloba extract consumption, and control-placebo. The training was carried out for 12 weeks and 4 sessions per week. Ginkgo biloba extract (80 mg) was administered as two capsules once a day after breakfast for 12 weeks. Blood samples were taken before and 48 hours after the last training session. Data were analyzed using two-way analysis of variance with SPSS-26 software. Results: The results showed that the interaction effect of exercise and ginkgo biloba extract, as well as the effect of exercise and ginkgo biloba extract alone, caused a significant decrease in the serum levels of interleukin-8 and interleukin-1β (p<0.05). The highest percentage of changes in interleukin-8 and interleukin-1β were obtained following exercise intervention along with the consumption of Ginkgo biloba extract. Conclusion: Performing high-intensity functional exercises with Ginkgo biloba extract had the greatest effect in reducing serum levels of inflammatory indicators and improving oxidative stress conditions in firefighters.

Serum Total Testosterone Levels Predict Cardiovascular Risk In Male Brazilian Firefighters

Serum Total Testosterone Levels Predict Cardiovascular Risk In Male Brazilian Firefighters

Physiological and perceptual responses of firefighters wearing protective clothing under various training environment and activity conditions

To enhance operational capabilities of firefighters in live-fire scenarios, daily training is absolutely important which involves various types of training tasks in diverse thermal environments. Fire training in heat may impose severe heat stress on firefighters. Yet, the thermal burden associating with different training has rarely been studied. In this study, twelve healthy male firefighters performed 50 min of treadmill exercise while wearing firefighting protective clothing (FPC) in two environmental conditions (34°C and 37°C) with three training intensities (3 km/h, 4.5 km/h and 6 km/h). Results showed that in hot environments, training intensity exhibited a more pronounced effect on physiological responses than ambient temperature. Exposure to 37°C with heavy activity produced high level of core temperature (38.8±0.2°C), near maximal heart rate (164±18 bpm), increased energy expenditure (27.10±1.42 ml/min/kg) coupled with mild dehydration (2.08%±0.35%). The forehead, back and chest which showed the highest level of thermal sensation vote, wetness sensation vote and thermal comfort vote are suggested to be primarily considered when designing cooling strategies. Moreover, when providing recovery and cooling for firefighters working in extreme heat while wearing fully encapsulated FPC, the priority should be given to work intensity and duration, followed by environmental conditions.

A field investigation of 3 masks proposed as respiratory protection for wildland firefighters: a randomized controlled trial in British Columbia, Canada.

Wildland firefighters are exposed through the lungs and skin to particulate matter, fumes, and vapors containing polycyclic aromatic hydrocarbons (PAH). Wearing respiratory protection should reduce pulmonary exposure, but there is uncertainty about the most effective and acceptable type of mask. Firefighters from 6 unit crews working with the British Columbia Wildfire Service were approached and those consenting were randomly allocated within each crew to a "no mask" control group or to use 1 of 3 types of masks: X, half-face respirator with P100/multi gas cartridge; Y, cloth with alpaca filter; Z mesh fabric with a carbon filter. Crews were followed for 3 consecutive firefighting days. The mask allocated was constant for each firefighter throughout. All participants completed a brief questionnaire at the start and end of each day, giving information on mask use, respiratory symptoms, and assessment of mask qualities. Spot urine samples were collected pre and post shift to assess 1-hydroxypyrene (1-HP) concentration as an indicator of total PAH absorption. Skin wipe samples from the hands and throat were collected pre and post shift and analyzed for PAH concentration. On each day monitored, 4 participants carried sampling pumps to measure total particulates and PAHs on particles and in vapor phase. The primary outcome was the concentration of urinary 1-HP at the end of the fire day. Secondary outcomes were changes in respiratory and eye symptoms during the course of the shift, reported mask use, and perception of mask qualities. The analysis used a 3-level random intercept regression model that clustered observations within individuals and crews. We aimed to detect any relation of allocated mask type to the 4 outcomes, having allowed for estimated exposure. Information was collected from 89 firefighters, including 14 women: 49% (37/75) of male firefighters were bearded. Nineteen fire days were monitored for a total of 263 firefighter × days, 64 to 68 for each intervention group. The end of shift 1-HP was higher than the start of the shift. Urinary 1-HP was more strongly related to PAHs on the skin than in the breathing zone. Men with beards had higher end-of-shift urinary log 1-HP/creat (ng/g) than other firefighters. None of the groups allocated a mask had lower 1-HP than the no-mask group, either in the study group overall or when stratified by beard-wearing. Among those without either beards or a failed fit-test, Mask Z reduced at the end of shift 1-HP where airborne PAH concentration was high. End-of-shift symptoms were related to particle mass in the breathing zone but was not mitigated by any of the masks. Hours electing not to wear a mask increased from the first to third shift for all mask types. Mask Z was rated as more comfortable than other types. Mask X was rated highest on fit and perceived protection. Mask Y gained the lowest ratings on fit, comfort and feelings of protection. Allocated masks did not provide protection overall, but the results highlighted the need for a wider understanding of the circumstances in which wearing efficient protection is well-advised.

Cancer incidence in a cohort of Danish firefighters: An extended long-term follow-up 1968-2021.

To update and extend the examination of cancer incidence in a cohort of Danish firefighters, now adding 7 years of follow-up and 2766 additional firefighters. The primary focus was directed toward cancer sites that recently contributed to the hazard evaluation conducted by the International Agency for Research on Cancer (IARC). The updated cohort consisted of 11,827 male Danish firefighters who were followed up for cancer from 1968 to 2021. Cohort cancer morbidity was compared with a working population reference group, and standardized incidence ratios (SIR) were used for estimation of relative risks, along with 95% confidence intervals (95% CI). Among full-time firefighters, SIR of skin melanoma was 1.30 (95% CI: 1.02-1.66), and SIR = 1.37 (95% CI: 1.02-1.85) for over 5 years of employment. Slightly positive associations were also observed for cancer of the urinary bladder (SIR = 1.16; 95% CI: 0.93-1.45), prostate (SIR = 1.11; 95% CI: 0.97-1.28), and testis (SIR = 1.11; 95% CI: 0.75-1.63). This updated study provides evidence indicating an elevated risk of skin melanoma in firefighters. Consistent with IARC's evaluation, we also identified positive associations for urinary bladder, prostate, and testis cancer. In contrast, our findings did not suggest an increased risk of colon cancer, non-Hodgkin lymphoma, and mesothelioma. The latter may be due to small numbers in our still relatively young cohort. Continuous follow-up for cancer in firefighters is warranted, including assessment of influence from surveillance bias.

Sleep Differences in Firefighters: Barracks vs. Home.

The aims were (1) to quantify firefighters' sleep via polysomnography, (2) to identify differences between sleeping in the barracks versus sleeping at home, and (3) to compare firefighter data to age-matched normative data. We expected significant differences between both the home and the barrack conditions as well as significant differences when both conditions were compared to normative data. 10 male firefighters completed 3 nights of polysomnography recordings (SleepProfilerTM (Advanced Brain Monitoring, Carlsbad, CA, USA)) counterbalanced in both their own beds or barracks. A one-way rmANOVA statistical analysis was used to determine differences in sleep values with a Bonferroni correction if a significant difference was found with significance set at p < 0.05. Three important variables, cortical arousals (p < 0.05), autonomic activations (p < 0.01), and spindle duration (p < 0.01), had differences that were statistically significant between sleep at home or in the barracks, with sleep in the barracks being more disturbed. Clinical differences were also observed between the home and barrack conditions and all sleep results were more deleterious when compared to normative data. The data demonstrates that firefighters show poor sleep quality and heavily impacted sleep architecture. This may be due to the effects of rotating shifts and occupational stress on the sleep-wake cycle. These results, when compared to age-matched normative data, show clinical manifestations of disturbed sleep in the firefighter population.

Associations between Dietary Intake and Cardiovascular Disease Risk in American Career Firefighters: An Observational Study.

Firefighters have demanding jobs, requiring high levels of fitness in stressful situations for operational readiness, yet many firefighters are at an increased risk of developing cardiovascular disease (CVD). Diet is an important factor contributing to the development of CVD. The purpose of this study was to describe the dietary intake of firefighters and examine the associations between dietary intake and the CVD risk. Forty-six male career firefighters (age = 41.2 ± 11.2 years; BMI = 29.2 ± 4.1 kg/m2; body fat = 21.7 ± 6.1%) enrolled in a fitness-focused wellness program completed a health survey and a fitness assessment. The survey responses and fitness assessment were used to calculate the Framingham CVD Risk Score. Data were analyzed using R, the residual assumptions were verified, and the alpha level was set at 0.05. The results revealed that firefighters consume a standard American diet, with the overconsumption of meat and underconsumption of fruits and vegetables. The average CVD risk approached the upper limit of low risk. The results also indicate that meat servings and preparation fat affect the CVD risk (R2 = 0.21, p = 0.006). The outcomes of this study can inform investigations aimed at improving operational readiness and reducing the CVD risk in firefighters by implementing a holistic approach combining dietary interventions with physical training.

Assessment of the Psychological Effects on Firefighters in the Aftermath of the Pazarcik and Elbistan Earthquakes in 2023.

In February 2023, two catastrophic earthquakes in Turkey resulted in over 50,000 fatalities and over 300,000 injuries. This study investigated the psychological effects on firefighters who engage in rescue operations following these earthquakes, focusing on trauma-related symptoms, depression, anxiety, stress, and resilience. The research employed validated psychometric instruments, including the Post-earthquake Trauma Level Determination Scale (PETLDS); Depression, Anxiety, Stress Scale-21 (DASS-21); PTSD Checklist for DSM-5 (PCL-5); and Brief Resilience Scale (BRS), to assess the psychological states of firefighters. The primary goal of this study was to evaluate the psychological impact of earthquakes on firefighters. Specific objectives include quantifying trauma levels; identifying the prevalence of post-traumatic stress disorder (PTSD), depression, anxiety, and stress among firefighters; and investigating the role of psychological resilience in mitigating the effects of disaster-related psychological trauma. This study is also aimed at providing empirical evidence to inform the development of psychological support and intervention strategies for firefighters in the aftermath of these earthquakes. In this study of 223 primarily male firefighters, significant psychological impacts from earthquake trauma were observed. The PETLDS scores indicated high trauma levels in 28 participants and modest levels in 195. Subscales revealed affective responses and cognitive structure were most affected. DASS-21 scores showed higher depression, anxiety, and stress in the high trauma group. PCL-5 and BRS analyses confirmed higher PTSD symptoms and lower resilience in high-trauma individuals. Correlation analysis highlighted strong associations between trauma, psychological distress, and decreased resilience. These findings highlight the necessity for targeted mental health interventions and support mechanisms for firefighters, contribute to the establishment of training programs to enhance psychological resilience among firefighters, and add valuable insights to the field of disaster psychology.

Firefighters' muscle activity change during firefighting training program.

Research on muscle activity to reduce injuries during firefighting training has getting increasing attention. The purpose of this study was to assess the activity changes in nine muscles of firefighters during the seven firefighting training programs, and to analyze the influence of different firefighting training programs on muscle activity. Ten healthy male firefighters were recruited to measure the field surface electromyographic activities (including the percentage of Maximum Voluntary Contraction electromyography (% MVC) and the integrated electromyography value (iEMG)) during all the firefighting training programs. The results showed that the electromyographic activity of gastrocnemius (GA) was stronger in climbing the hooked ladder and climbing the six-meter long ladder training programs. Arms, shoulders, and lower limb muscles were more activated, myoelectric activities were more intense, and fatigue in these areas was more likely to occur during climbing five-story building with loads. Compared with other muscles, erector spine (ES) had a higher degree of activation during different postures of water shooting. The Borg scale scores of shoulders, trunk, thighs and calves were also higher. After completing all training programs, GA, tibialis anterior (TA), trapezius (TR), and ES were strongly activated, and all muscles had obvious force. The % MVC and iEMG analyses correspond well with the Borg Scale score. The results can provide certain reference for reducing the musculoskeletal injury of firefighters, carrying out scientific training and formulating effective injury prevention measures for them.

Odds of developing cancer among male and female volunteer firefighters in Florida: A case-control study design.

Determine whether volunteer firefighters in Florida are at increased odds of developing cancer compared to non-firefighters. A case-control study design was implemented to assess the odds of developing cancer among male and female volunteer firefighters in Florida. Gender-specific age and calendar year-adjusted odds ratios (aOR) and 95% confidence intervals (95%CI) were estimated. Male volunteer firefighters were at increased odds for developing prostate (aOR = 1.26; 95%CI;[1.10- 1.44]) and male genital cancers combined (1.22;[1.07-1.39]), while reduced odds for endocrine cancer (0.41;[0.17-1.00]), and all leukemias (0.55;[0.35-0.86]), including lymphocytic (0.48;[0.24-0.97]); and chronic lymphocytic (0.40;[0.17-0.97]) leukemias. Female volunteer firefighters were at increased odds of developing of kidney cancer (2.51;[1.29-4.91]). Male volunteer firefighters are at increased odds for prostate and overall male genital cancers, while female volunteers are increased odds of kidney cancer.

Concurrent Validity and Inter-Rater Reliability Assessment of Two Mental Toughness Instruments in Firefighting: A Two-Wave Longitudinal Study.

Mental toughness (MT), a construct linked to high-stress performance, is predominantly studied via self-assessment in cross-sectional designs. In the firefighting context, where no dedicated MT instrument exists, the Sports Mental Toughness Questionnaire (SMTQ) and the Military Training Mental Toughness Inventory (MTMTI) have been used. However, their reliability and concurrent validity remain unexamined. This study employs a two-wave longitudinal design involving sixty-two male firefighters. Over two days, they completed the SMTQ, while colleagues and officers assessed their MT using the MTMTI. Analyses included concurrent validity and inter-rater reliability tests. Inter-rater reliability exhibited minimal agreement (Day 1: κ = 0.04, p = 0.172; Day 2: κ = 0.05, p = 0.063), low internal consistency (Day 1: α = 0.03, ω = 0.03; Day 2: α = 0.45, ω = 0.45), and weak inter-rater correlations (Day 1: ICC2k < 0.001, 95%CI [-0.53, 0.35]; Day 2: ICC2k = 0.13, 95%CI [-0.33, 0.43]). Concurrent validity showed limited correlations between self-assessed SMTQ scores and MTMTI ratings on both days (Day 1: r = -0.09, p = 0.5; Day 2: r = 0.1, p = 0.5). These findings may underscore the necessity to develop firefighting-specific MT tools, recognizing the unique demands and nuances of this high-stress profession.

Musculoskeletal Discomfort and Musculoskeletal Injuries in Firefighters of the City of Cape Town Fire and Rescue Service

Objective The prevalence of work-related musculoskeletal injuries is reported to be noticeably high amongst firefighters, which augments the dangers of the job and the difficulties that firefighters must face daily. Therefore, this study aimed to firstly determine the prevalence and characteristics of work-related musculoskeletal injuries (MSIs) and musculoskeletal discomfort (MSD) and, secondly, to determine the relationship between MSD and MSIs in firefighters. Methods Using random systematic sampling, 309 firefighters from the City of Cape Town Fire and Rescue Service were recruited to participate. A researcher-generated questionnaire was used to retrieve data on musculoskeletal injuries and musculoskeletal discomfort. Data was analysed using the T-tests, Cochran-Armitage trend test, Jonckheere-Terpstra test, and Binary logistic regression. A p-value of less than 0.05 was used to indicate statistical significance. Results Male (p = 0.036) and older firefighters (p&lt;0.001) with more years of experience (p = 0.002) were most likely to report a musculoskeletal injury. Falls, jumps, slips, and trips were the most common injuries (39.7%), which most often occurred on the fireground (41.1%). Most firefighters (73.3%) reported experiencing discomfort 1-2 times a week of moderate (60.1%) severity that interfered slightly with their ability to work (58.2%). Multivariable analysis showed that the age groups of 40-49 years and 50-65 years and the rank of station commander increased the risk for MSIs by a factor of 2.39, 2.67, and 3.83, respectively. In addition, MSD was associated with an increase in the likelihood of firefighters reporting MSIs (p &lt;0.001). Conclusion Older male firefighters with more years in service were most likely to experience MSIs. Regular physical activity and work-related training should be implemented to increase the fitness for duty and to reduce the prevalence of injuries in firefighters.

Heat strain in professional firefighters: physiological responses to a simulated smoke dive in extremely hot environments and the subsequent recovery phase.

Firefighters risk heat strain during occupational tasks when exposed to extremely hot environmental conditions and performing high-intensity work. Relevant training scenarios are therefore essential. This study investigated the effect of a single simulated smoke dive and the following recovery phase on physiological and perceptual responses. Nineteen professional male firefighters (43 ± 8 yr) performed a 2-min stair walk and a15-min simulated smoke dive in a two-floor heat chamber (110°C to 272°C) (HEAT), followed by a 5-min stair walk outside the heat chamber. Heart rate (HR), gastrointestinal temperature (Tgi) and skin temperatures were registered continuously during the test. The Tgi increased significantly from the start (37.5 ± 0.3°C) to the end of HEAT (38.4 ± 0.4°C) and further increased after the heat exposure (39.6 ± 0.5°C). The HR also increased significantly from the start (92 ± 14 bpm) to the end of HEAT (185 ± 13 bpm) and increased after the heat exposure to a maximum of 190 ± 13 bpm. The simulated smoke dive induced high physiological strain on the firefighters, and the increase in Tgi and HR after the hot exposure must be considered during live fire events when repeated smoke dives are required.

A 7-Month Multidisciplinary Healthy Lifestyle Intervention Effectively Improved Cardiometabolic Risk Profile of Firefighters.

We investigated the effect of a 7-month healthy lifestyle intervention on cardiometabolic risk factors (CMRF) among male career military firefighters (FFs). Forty-nine FFs participated in a 7-month workplace multiddisciplinary healthy lifestyle intervention designed to reduce CMRF through exercise, diet, and improved sleep. Medical assessments, accelerometry, and surveys at the beginning and end determined program effectiveness. At the end of the intervention period, there was a significant improvement in measures of body composition and blood glucose. The prevalence of hypertension also decreased significantly ( P < 0.01). The 57% of participants who fully adhered to the program had significantly greater improvements across multiple CMRF. Participants increased their physical activity and improved their diet following the intervention. This healthy lifestyle intervention was effective in changing behavior and lowering cardiometabolic risk among FFs.

Determination of dynamic air gap thickness and analysis of its relationship with firefighters’ joint movement

ABSTRACT Objectives. The purpose of this study was to calculate the dynamic air gap thickness between the human body and the turnout gear. Relationships between the air gap thickness and joint range of motion (ROM) were also explored. Methods. The air gap thickness and joint ROM of 12 male firefighters walking in a control condition with no self-contained breathing apparatus (SCBA) and three varying-strapped SCBAs were measured using three-dimensional (3D) body scanning and 3D inertial motion capture. The interpolation technique was employed to predict the air gap thickness curve during walking. The dynamic air gap thickness was compared with the joint ROM to see how they relate to the location and percentage of movement restriction. Results. During the walking, the air gap fluctuated as a sine curve. Carrying SCBA reduced the air gap thickness at the trunk most (F = 11.17, p < 0.001, η 2 = 0.63), and adjusting the shoulder strap length altered the air gap distribution at the trunk. The reduced air gap at the pelvis caused an incremental restriction on pelvis rotation. Conclusions. A compatibility design of the shoulder strap and hip belt in SCBA with the turnout jacket is suggested.

Age-Related Differences in Physical Fitness and Performance of an “Ability Test” among Firefighters

This study’s primary objective was to examine the differences in body composition, abdominal strength, absolute and relative power, handgrip strength, one repetition maximum for squat and bench press, and the maximum count of push-up and sit-up repetitions executed within a minute across different age cohorts of firefighters. Furthermore, this study aimed to evaluate the age-related differences in firefighters’ completion times of six firefighting tasks. Eighty-four male volunteer firefighters (age 33.79 ± 6.97 years) were grouped into three age categories, 20–30 years, 31–40 years, and 41–50 years, and underwent the aforementioned evaluations. One-way analysis of variance (MANOVA) revealed that age exerts a statistically significant influence (p &lt; 0.001) on body fat percentage, waist circumference, and waist-to-hip ratio. Furthermore, age significantly affected the overall time of the ability test (p &lt; 0.001) and the duration required to accomplish each individual task (p &lt; 0.001). Additionally, age significantly affected abdominal strength, relative power (as measured by the step test), and the maximum count of push-up and sit-up repetitions performed within a minute. These outcomes support earlier research indicating an age-associated decrement in physical fitness parameters among firefighters. It is recommended that firefighters prioritize maintaining strength and endurance of the abdominal muscles, upper body muscular endurance, and a healthy body weight. The emphasis on specific muscular groups is essential for improving task performance within this profession.

Association of Endogenous Testosterone with Physical Fitness Measures during Firefighter Occupational Health Evaluations.

Firefighting is a physically demanding profession associated with unacceptably high on-duty cardiovascular mortality. Low endogenous total testosterone (TT) is an emerging cardiometabolic (CM) risk factor in men, but limited data exists on its interactions with physical fitness (PF). Data from occupational health and fitness assessments of 301 male career firefighters (FFs) were analyzed. TT was categorized as low (<264 ng/dL), borderline (264-399 ng/dL), and reference (400-916 ng/dL). PF tests included cardiorespiratory fitness (submaximal treadmill), body fat percentage (BF%), push-ups, plank, and handgrip strength assessments. In the crude analyses, FFs in the low TT group had worse muscular and cardiorespiratory fitness measures compared to the referent group. However, after adjusting for age and BF%, none of the PF differences remained statistically significant. Similarly, the odds of less-fit FFs (PF performance below median values) having low TT were higher compared to the fitter ones only before adjusting for age and BF%. Therefore, in the final adjusted model, there was no significant association between TT and PF. Our data suggest that age and body fat confound the association between PF and TT. Low TT and poor PF are important components of FFs' CM risk profile, and there is potential benefit to considering TT screening as part of a comprehensive occupational health program that manages performing medical evaluations and provides education and preventative programming.

남자간호사의 병원간호사에서 소방공무원으로의 이직 의도

This is a qualitative study that applied the focus group interview research method in order to explore turnover intentions of male nurses from hospital nurses to firefighters. The purpose of this study is to prevent the turnover of male nurses by gaining an in-depth understanding of clinical experiences of male nurses and analyzing major factors in the clinical field that affect the turnover to firefighters, and to provide basic data to prepare measures that can be applied to the clinical site. The study data targeted 10 male firefighters, former male nurses, who were first assigned as firefighters and receiving training at the fire service academy. The main questions were “What motivated you to decide to change your job to a firefighter?” and “How was your clinical work experience?”. As a result of the analysis, 34 meaning units were created, and 15 subcategories and 5 categories were derived. The five categories were analyzed as ‘skepticism about adequate compensation and future vision of nursing,’ ‘organizational culture that is difficult to be harmonized as an insider,’ ‘disrespected role and position,’ ‘vulnerable support system of nursing organization within the hospital,’ and ‘challenges to a new role.’&#x0D; Based on the study results, it was found that in order to prevent the turnover of male nurses, measures to overcome gender stereotypes that reflect the special characteristics of the clinical field should be prepared, and sufficient training courses, generosity that supports the process of juniors’ growth, and servant leadership should be established. It is also believed that systematic institutional support is required to represent the difficulties in clinical fields and improve the rights and treatment of nurses.

Biomechanical characterization of firefighters running under different rescue tasks

The biomechanical characteristics of runs in firefighters with different rescue tasks are unclear. This study aimed to explore the biomechanical characteristics of firefighters running in different rescue tasks and provide theoretical and practical references for firefighter training and occupational injury prevention. Eighteen professional healthy male firefighters were randomly selected as participants and tested running on different rescue tasks: wearing firefighting protective clothing (FPC), FPC+carrying a gas can (20 kg, FPC+ C), and FPC+carrying a mannequin (60 kg, FPC+M). Eight Qualisys infrared cameras and an AMTI 3D force measurement platform were used for the participant's acquisition of lower limb kinematic/kinetic data. The results showed that gait velocity and stride length of the FPC+GC and FPC+ M rescue tasks were significantly decreased compared to the FPC rescue task, while the support time was significantly increased. Compared to the FPC rescue task, the FPC+GC rescue task showed significant decreases in vertical ground reaction force (vGRF), minimum ankle dorsiflexion angle, and the maximum ankle plantarflexion power. In contrast, the FPC+M rescue task demonstrated significant increases in ankle range of motion, maximum hip extension angle, minimum knee flexion angle, maximum ankle dorsiflexion angle, maximum hip extension moment, maximum knee flexion moment, maximum hip flexion power, and hip and knee stiffness while exhibiting significant decreases in minimum ankle dorsiflexion angle. Compared to the FPC+ GC rescue task, the FPC+M rescue task exhibited significant increases in the maximum hip extension angle, minimum knee flexion angle, maximum ankle dorsiflexion angle, maximum hip flexion moment, maximum hip extension moment, maximum knee flexion moment, maximum ankle plantarflexion moment, maximum hip flexion power, maximum ankle dorsiflexion power, hip stiffness, and vGRF. Conversely, it showed significant decreases in the maximum knee flexion power. In conclusion, compared to the FPC rescue task, the FPC+GC and FPC+M rescue tasks altered the firefighter's gait performance, as evidenced by decreased gait velocity and stride length and increased support time. FPC+M rescue task would increase firefighter's risk of hip and knee injuries. Therefore, we suggest firefighters increase their strength training of the trunk, hip, and knee joint muscles as part of their daily training programs under large weight load status (60 kg and above) to reduce injury risk during rescue tasks.

On-Duty Resting Heart Rate Variability at the Fire Station Is Related to Cardiorespiratory Fitness and Physical Activity Levels in Firefighters.

The aim of the study is to measure the association between the physical activity (PA) levels and cardiorespiratory fitness on the firefighters' cardiac autonomic function at rest at the fire station. Anthropometry, heart rate variability, fitness, and PA levels were assessed at the fire station in 98 career Québec male firefighters. Partial correlations, adjusted for age, waist circumference, and perceived stress revealed that heart rate and several heart rate variability indices were significantly correlated to estimated maximal oxygen consumption and to high-intensity PA but not to moderate-intensity PA. These results suggest that both cardiorespiratory fitness and high-intensity physical training are related to the cardiac autonomic function of firefighters. Therefore, fire department should promote PA programs to improve physical fitness among firefighters.