Age and physical activity status of Australian volunteer firefighters: a cross-sectional study

Introduction

Wildfire frequency and severity are increasing globally (Hennessy et al. 2005; Liu et al. 2010). Recent wildfire devastation has been witnessed across Europe, Asia, the Americas and Australia (Liu et al. 2010; Aisbett et al. 2012; Bowman et al. 2017). Beyond the destruction of millions of hectares of land, wildfires present a significant threat to the economy and human life. In the 2019–2020 Australian fire season, wildfires directly claimed 33 lives (Filkov et al. 2020), and were indirectly responsible for an estimated 171 deaths due to reduced air quality (Graham et al. 2021). In the same season, Australian insurers paid out more than AU$6.1 billion owing to wildfire damage and destruction (Insurance Council of Australia 2021). The negative impacts of Australian wildfires are predicted to worsen over the next decade (Ademi et al. 2022).

The increasing number and severity of wildfires have placed greater demands on Australian firefighters, including the volunteer population. Australia had an estimated 220,000 volunteers in 2004 (McLennan 2004), which was similar to 2012 estimates (Productivity Commission 2023). The volunteer population has steadily declined since 2012, to an estimated 193,000 volunteers in 2021 (Productivity Commission 2023). Volunteer firefighters assist in firefighting activities within their local community without receiving financial compensation. Volunteers play a crucial role in providing firefighting services and supporting professional firefighters during emergency situations, particularly in rural Australian areas where the population density and resources are low. As volunteers typically hold a full-time occupation, they have less time for physical and firefighting training compared with salaried personnel (Malinen and Mankkinen 2018). Nonetheless, the value of volunteers cannot be overestimated, and they have an increasingly critical role in combating Australian wildfires as the duration and intensity of the fire season increase.

Volunteer firefighters are required to undertake physically demanding tasks (Phillips et al. 2012) in hazardous environments (Guidotti 1992; Navarro 2020). A 2012 study by Phillips et al. identified that the physically demanding tasks undertaken by volunteers primarily relied on strength-endurance and could be broadly categorised as either hose work or hand tool work. Tasks may take anywhere from 3 to 30 min per repetition, and in some cases, are performed up to 700 times across a fire season (Phillips et al. 2012). Owing to these physical demands, the fitness of volunteers is critical, not only because increased strain could decrease an individual’s operational effectiveness, but also because of the increased risk of cardiovascular events, which are estimated to account for 26% of line of duty deaths in Australian volunteer firefighters (Glass et al. 2017). From a workforce perspective, the fitness of volunteers is important as a lack of fitness may deter new recruits, and could contribute to difficulties in retaining volunteers (Birch 2011).

There have been recent concerns regarding an aging volunteer firefighter population and its capability to handle the demands of a hotter and longer fire season (Colibaba et al. 2021), particularly in light of other challenges such as decreasing volunteering rates (McLennan et al. 2016; Productivity Commission 2023). Unfortunately, there is a lack of recent literature on the demographics of Australian volunteer firefighters, with the largest study on volunteers including data up until the early 2010s (Glass et al. 2017) and other commissioned work dating back to the 2000s (McLennan and Birch 2005). Although an aging workforce can be positive in that it brings invaluable experience and oversight, which may reduce volunteering-related mental stress (Moran and Colless 1995), the relative physical demands of volunteering can become greater with age, owing to decreased muscular power and strength endurance, and a decline in cardiovascular fitness (Perroni et al. 2014). For example, in Australian salaried firefighters, maximal aerobic capacity, grip strength and performance in fire-specific tasks (e.g. hose drag) were found to decrease with increase in age (Walker et al. 2014). Intense exercise training can assist in minimising age-associated declines in physical capacity (Walker et al. 2014); however, evidence suggests that older firefighters are less likely to engage in such activity (Phillips et al. 2012). There are limited published data on physical activity behaviours in volunteer firefighters, with existing studies involving American volunteers only (Martin et al. 2019; Amodeo and Nickelson 2020).

To meet the Australian physical activity and sedentary behaviour guidelines, adults 18–62 years of age must accumulate at least 150 min of combined workplace activity and exercise-only minutes per week (Department of Health and Aged 2021). To meet the strength-training guidelines, adults must participate in strength-based training activities at least twice per week. No guidance on exercise duration is provided for strength-based training activities. No previous study of Australian volunteer firefighters has investigated the proportion of active volunteers that meet these guidelines.

This study aimed to: (1) determine the age distribution of Australian volunteer firefighters; (2) estimate the proportion of volunteer firefighters who met the national physical activity guidelines; and (3) investigate the relationship between age and physical activity and exercise in volunteer firefighters.

Methods

The survey was developed for volunteer firefighters and included demographic, anthropometric and service questions, in addition to physical activity questions from the 2016–2018 Australian National Health Survey (Australian Bureau of Statistics 2018). National guidelines (Department of Health and Aged 2021) were used to determine whether respondents met the Australian recommendations for weekly physical activity and strength-based training, enabling comparison with population estimates (Australian Bureau of Statistics 2018).

Reporting of the survey and results was guided by the STROBE reporting guidelines for cross-sectional studies (Von Elm et al. 2014) and the CHERRIES reporting guidelines for online questionnaires (Eysenbach 2004).

Results

Age

Fig. 1 shows the age distribution of the sample. The median age of respondents was 54 years. The interquartile range spanned from 40 to 64 years and the central 90% quantile spanned from 23 to 72 years. The mean age was 51.4 years (95% bootstrap CI = 50.0–52.8).

Fig. 1.

The distribution of age, using 1-year bin widths. The central 90% interval spanned from 23 to 72 years (wide horizontal line) and the interquartile range spanned from 40 to 64 years (narrow horizontal line). The dark black circle indicates the mean age (51.4 years), and the error bars indicate the 95% bootstrap confidence interval, which spanned from 50.0 to 52.8 years.

Physical activity

The proportion of volunteer firefighters who met the Australian guidelines for: physical activity, χ² (N = 17,193,480) = 1533.00, P < 0.001; exercise-only activity, χ² (N = 17,195,980) = 1390.80, P < 0.001; and strength-based activity, χ² (N = 21,340,480) = 49.61, P < 0.001, was different to the Australian population. Compared with the Australian population, volunteer firefighters were 4.87 times more likely to meet the physical activity guidelines, 4.96 times more likely to meet the exercise only guidelines, but 1.26 times more likely to not meet the strength-based activity guidelines (Table 2).

Table 2.The percentage of volunteer firefighters who met the physical activity guidelines and physical activity on a typical workday compared with Australian population estimates from the 2017 to 2018 National Health Survey.

Variable	Australian population A	Volunteer firefighters	RR	RR 95% CI lower, upper
Any physical activity B
Met guidelines C	3,023,600 (17.6%)	411 (85.6%)	4.87	4.69, 5.05
Did not meet guidelines	14,169,400 (82.4%)	69 (14.4%)	0.17	0.14, 0.22
Exercise only B
Met guidelines C	2,677,400 (15.6%)	371 (77.3%)	4.96	4.73, 5.21
Did not meet guidelines	14,518,100 (84.4%)	109 (22.7%)	0.27	0.23, 0.32
Strength-based activity B
Met guidelines C	8,278,000 (38.8%)	111 (23.1%)	0.60	0.51, 0.70
Did not meet guidelines	13,062,000 (61.2%)	369 (76.9%)	1.26	1.20, 1.32
Type of physical activity on a typical workday D
Mostly sitting	4,876,400 (43.9%)	164 (37.9%)	0.86	0.76, 0.98
Mostly standing	2,164,900 (19.5%)	54 (12.5%)	0.64	0.50, 0.82
Mostly walking	2,557,100 (23.0%)	89 (20.1%)	0.89	0.74, 1.08
Mostly heavy labour or physically demanding work	1,521,800 (13.7%)	126 (29.1%)	2.13	1.82, 2.48

Note: CI, confidence interval; RR, relative risk. Percentages may not sum exactly to 100 owing to rounding. Boldface indicates the 95% confidence interval of the relative risk does not include the null value of one.

^A Australian adult (18–74 years) population data sourced from published 2017–2018 National Health Survey results.

^B Any physical activity refers to a combination of exercise-only and workplace activity. Exercise-only consists of four domains: walking for transport, walking for fitness, sport or recreation, moderate exercise and/or vigorous exercise undertaken in the last week. Workplace activity is physical activity undertaken in the workplace, which consists of two domains: moderate and/or vigorous workplace activity undertaken on a typical workday.

^C Per Australia’s Physical Activity and Sedentary Behaviour Guidelines, adults should: (1) accumulate at least 150 min of moderate intensity physical activity or at least 75 min of vigorous intensity physical activity, or an equivalent combination of both moderate and vigorous activities each week; and (2) undertake muscle strengthening activities on at least 2 days of each week.

^D Missing data (n = 47) for the volunteer firefighter group; not accounted for by calculated percentages.

Volunteer firefighters were 2.1 times more likely to be involved in heavy labour or physically demanding work on a typical workday compared with the Australian population, and less likely to be involved in work mostly sitting or standing, χ² (d.f. = 3, N = 11,120,633) = 90.71, P < 0.001 (Table 2).

Physical activity duration and frequency are displayed in Fig. 2. The median daily physical activity time was 111 min (first and third quartile = 51–235), and the median daily exercise-only time was 60 min (first and third quartile = 26–119). The median daily moderate intensity exercise time was 9 min (first and third quartile = 0–21). Forty-two percent (n = 200/480) of respondents had not participated in moderate intensity exercise in the past week. The median daily vigorous intensity time was 0 min (first and third quartile = 0–17). Fifty-nine percent (n = 284/480) of respondents had not participated in vigorous intensity exercise in the past week. Sixty-one percent (n = 295/480) of respondents had not participated in strength-based activity in the past week.

Fig. 2.

Physical activity and exercise-only minutes (top panel), and days of physical activity, exercise-only and strength-based activities undertaken in the past week (bottom panel). Any physical activity refers to a combination of exercise-only and workplace activity. Exercise only consists of four domains: walking for transport, walking for fitness, sport or recreation, moderate exercise and/or vigorous exercise undertaken in the last week. Workplace activity is physical activity undertaken in the workplace, which consists of two domains: moderate and/or vigorous workplace activity undertaken on a typical workday.

Relationship between age and physical activity

The number of weekly physical activity minutes declined with age (β = –0.0055, 95% CrI = −0.0115, 0.0006; Pr β < 0 = 0.963), by on average 61 min with each decade increase in age (Fig. 3a). We did not find any evidence that age was associated with a decline in weekly exercise-only minutes (β = –0.001, 95% CrI = –0.008, 0.005; Pr β < 0 = 0.64; Fig. 3b).

Fig. 3.

The relationship between age and weekly physical activity minutes (a), and between age and weekly exercise only minutes (b); and the contribution of walking for travel (c), walking for fitness (d), moderate intensity exercise (e), vigorous intensity exercise (f), and workplace activity (g) to weekly physical activity minutes. The dark line indicates the posterior mean. The shaded ribbon indicates the 66% (blue inner ribbon) and 95% (light blue outer ribbon) credible interval. There was a decline in weekly physical activity minutes with aging, but no change in weekly exercise-only minutes. Walking for travel, walking for fitness and moderate intensity exercise accounted for a higher proportion of weekly physical activity minutes with aging. Vigorous intensity exercise and workplace activity accounted for a lower proportion of weekly physical activity minutes with aging.

Walking for travel accounted for a higher proportion of weekly physical activity minutes with increases in age (β_(0,1) = 0.0064, 95% CrI = 0.0005, 0.0123; Pr β > 0 = 0.983), by on average 0.81% with each decade increase in age (Fig. 3c). Walking for exercise accounted for a higher proportion of weekly physical activity minutes with increases in age (β_(0,1) = 0.008, 95% CrI = 0.002, 0.014; Pr β > 0 = 0.996), by on average 0.83% with each decade increase in age (Fig. 3d).

Moderate activity accounted for a larger proportion of weekly physical activity minutes with increases in age (β_(0,1) = 0.009, 95% CrI = 0.001, 0.017; Pr β > 0 = 0.988), by on average 0.60% with each decade increase (Fig. 3e). Vigorous intensity exercise accounted for a lower proportion of weekly physical activity minutes with increases in age, decreasing by on average 1.19% with each decade increase (Fig. 3f). This was due to an increase in respondents doing no vigorous activity (β_{0} = 0.02, 95% CrI = 0.01, 0.03; Pr β > 0 = 1), rather than a reduction in vigorous activity minutes being undertaken (β_(0,1) = –0.002, 95% CI = –0.009, 0.005; Pr β < 0 = 0.688).

Work activity accounted for a lower proportion of weekly physical activity minutes with increases in age, decreasing by on average 1.44% with each decade increase in age (Fig. 3g). This was due to an increase in respondents doing no work activity (β_{0} = 0.010, 95% CrI = –0.002, 0.022; Pr β > 0 = 0.941), rather than a reduction in work activity minutes being undertaken (β_(0,1) = –0.003, 95% CrI = –0.010, 0.004; Pr β < 0 = 0.785).

Discussion

There are several insights from this survey of Australian volunteer firefighters. The mean age of the Queensland volunteer population was estimated to be between 50.0 and 52.8 years. Compared with the general Australian population, volunteer firefighters were: (1) twice as likely to perform physically demanding work in their career occupation; (2) over four times more likely to meet the physical activity guidelines in addition to the exercise-only guidelines; and (3) 1.4 times more likely to not meet the strength-based activity guidelines. We found that the number of physical activity minutes, but not exercise-only minutes, declined with age. Future studies should review current organisational approaches to the fitness of Australian volunteer firefighters. It is possible that volunteer firefighters could benefit from outreach programs that promote and/or facilitate exercise participation, particularly in strength-based training. A multi-site trial of such a program and its effect on volunteer fitness may be warranted.

The mean age of volunteers was estimated to be 51.4 years (Fig. 1), which is 12 years older than a 2017 study of 160,000 male volunteers (Glass et al. 2017) and 7.8 years older than the Queensland State Emergency Service volunteer population in 2019 (Queensland Government 2019). Exactly why the volunteer firefighter population would be older than State Emergency Service volunteers is unclear; yet it does raise concerns about age-related health issues, particularly in the context of evidence that 28% of volunteer resignations are due to age or health issues (McLennan et al. 2009). Although the recruitment of younger volunteers is important, of equal importance is the ability to retain young recruits. There is a lack of data on the propensity of younger volunteers to be retained. Time and financial costs have been indicated as significant deterrents to volunteering (O’Halloran and Davies 2020), secondary to decreased volunteerism (McLennan et al. 2016). These factors are likely to contribute to lower rates of younger Australians volunteering, particularly those with young families or multiple paid employments.

In 2018, it was estimated that only 17.6% of Australians met the national physical activity guidelines, with 15.6% meeting the exercise-only guidelines (Table 2). We found that volunteer firefighters were nearly five times more likely to meet these guidelines compared with the Australian population. There is a lack of data on physical activity behaviours of Australian volunteer firefighters. A study of 74 American male volunteers found that 46% were considered sedentary – defined as not achieving at least 30 min of moderate intensity physical activity on 3 or more days a week (Martin et al. 2019). Using this definition, 55% of our sample would be considered sedentary. An additional 8% of our sample met the weekly time requirement but did not exercise on 3 or more days, which would otherwise mean that 47% of our sample were considered sedentary, which is comparable with the American study (Martin et al. 2019). A separate study of 123 American volunteers found that 14% did not participate in any moderate intensity exercise and 41% did not participant in vigorous intensity exercise (Amodeo and Nickelson 2020), compared with 42 and 59% in our sample. This suggests that Australian volunteers undertake substantially less moderate and vigorous intensity exercise compared with their American counterparts. The generalisability of these estimates should be treated with caution owing to the small sample sizes of the comparison studies.

Decreased participation in moderate and vigorous intensity exercise is likely to increase the relative demands of firefighting independently of age, therefore increasing the associated risk of cardiac events (Walker et al. 2015). Worryingly, but not unexpectedly (Caspersen et al. 2000), we found that vigorous intensity activity accounted for a lower proportion of weekly physical activity minutes with aging (Fig. 3f). Aging was also associated with a decline in weekly physical activity minutes (Fig. 3a) but encouragingly, not exercise-only minutes (Fig. 3b). Our findings further support calls for the implementation of outreach programs that target physical activity behaviours in volunteer firefighter settings (Day et al. 2019; Martin et al. 2019). Although such programs may assist in ensuring volunteers maintain moderate and vigorous activity, they are no panacea, owing to the complexity of physical activity intention (Amodeo and Nickelson 2020). Programs should also include dietary education and support (Day et al. 2019), particularly when considering the high prevalence of overweight or obesity in volunteer firefighters (Martin et al. 2019) (71.5% in the current sample) and evidence that the risk of coronary heart disease risk is greater in volunteer firefighters compared with other volunteer and paid emergency services (Wolkow et al. 2014).

Despite the importance of strength endurance capacity when fighting wildfires (Phillips et al. 2012), 61% of respondents had not participated in strength-based activities in the past week and 77% did not meet the Australian strength activity guidelines (Table 2). Volunteers were 1.4 times more likely to not meet the guidelines compared with the Australian population. This result may be explained by volunteers being twice as likely to undertake heavy labour or physically demanding activities on a typical workday compared with the Australian population. Working in a physically demanding occupation such as farming, agriculture or construction could, at least in part, offset the need to participate in strength-based training. Nonetheless, participation in structured strength and conditioning training is still important (Westcott 2012; Bennie et al. 2020), particularly to offset the negative effects of age on strength (Westcott 2012), and this result should be further investigated. Sixty-one percent of volunteers did not participate in any strength-based training, which is higher than estimates of 45.2% in American volunteer firefighters (Amodeo and Nickelson 2020). Volunteer firefighters could benefit from outreach programs that promote and/or facilitate participation in strength-based training activities (Day et al. 2019).

The survey response rate was 2.38%, and therefore, caution should be taken when generalising from our findings. It is possible that our findings do not extend to volunteers from other Australian states. Further, the study results should be interpreted in the context of the cross-sectional design, such that the causal relationships between age and physical activity, and between age and exercise-only minutes, are unknown. New recruits may be over-represented in our sample, as nearly a quarter of respondents (23.8%) had 3 or less years of volunteering experience. We are unable to compare demographic data between survey responders and non-responders. Questionnaire-based measures of physical activity are known to overestimate activity levels, sometimes by as much as 170% (Lee et al. 2011). Using a conservative approach and halving the weekly activity minutes for each respondent, 75.8% of the sample still met the physical activity guidelines and 48.3% met the exercise-only guidelines. Using these values, volunteers were still 4.3 times (95% CI = 4.1–4.5) and 3.1 times (95% CI = 2.8–3.4) more likely to meet the physical activity and exercise-only guidelines compared with the Australian population. A summary of age (as a continuous variable) and body mass index could not be provided for the Australian population data, as age data were reported categorically only, and body mass index data were reported in a different age bracket (18 and older) to the physical activity data (18–74 years) used in our study. Females represented 50.7% of individuals in the Australian population data.

Conclusion

We estimated the mean age of Queensland volunteer firefighters to be 51.4 years, which is nearly 8 years older than the mean age of Queensland State Emergency Service volunteers. Compared with general the Australian population, volunteers were more likely to meet the national physical activity and exercise only guidelines, but less likely to meet the strength-based activity guidelines. Expected age-related declines in vigorous intensity exercise minutes were observed. There is a need to review the current organisational approaches to the fitness of Australian volunteer firefighters and consider whether volunteer firefighters could benefit from outreach programs that promote and/or facilitate exercise participation, particularly from strength-based training.

Supplementary material

Supplementary material is available online.