Improving Health on Shift

A paper published June 2024 in the Journal of Functional Morphology and Kinesiology attempts to address fatal and non-fatal injuries to firefighters by offering practical exercise and nutritional recommendations that can be implemented on-shift.

The study doesn't pull any punches, citing that more than 60,000 U.S. firefighters were injured in the line of duty in 2021 at an estimated cost burden of between 2.8 and 7.8 billion dollars. The most common causes were stress, overexertion, falls, slips, and trips. There doesn't seem to be any good argument for not extrapolating these figures (or the ones below) to the Canadian experience.

The paper cites studies concluding that sedentary workdays when not responding to calls, along with unhealthy dietary habits may cause subclinical cardiac dysfunction associated with obesity, hypertension, poor metabolic health, and low aerobic capacity. This is problematic when firefighters are suddenly called on to perform at near maximum physical capacity. The authors refer to firefighters as 'tactical' or 'occupational' athletes.

It struck me that some research has found that in the U.S. in 2011, obesity in the fire service was higher than in the general population, and in 2009 the majority of recruits were either overweight or obese. Not surprisingly, given that firehalls are often places where poor food choices go unnoticed, a 2022 study found that the body mass of firefighters increased with each year of service while another study determined that the increase in obesity was a high as 35 to 40 per cent over a five year period.

Exercise

The National Fire Protection Association 1583 Standard on Health-Related Fitness Programs for Fire Department Members is referenced by the authors when they state that, "fire departments should provide the means for regular exercise and firefighters assigned to a shift will be allowed time to exercise while on-shift," and, "a fire department's exercise program must contain: an educational program, individualized exercise programs, warm-up and cool-down guidelines, metabolic conditioning (aerobic and anaerobic), muscular resistance, flexibility and mobility, and an emphasis on the back, knees, and shoulders."

High Intensity Interval Training (HIIT) is suggested as the best option for firefighters on- shift primarily because it offers the greatest overall fitness benefits in the least amount of time. HIIT involves "repeated bouts of high-intensity exercise paired with bouts of recovery," and it can be conveniently completed either through running-based or cycle- based exercise. The authors note that both HIIT and resistance training, e.g. weights or bands, would comply with NFPA 1583. Some runners perform HIIT as 'sprinting'.

HIIT would be effective across the broadest group of firefighters, young to old, normal weight to obese, and trained or untrained – although a medical assessment of the ability to participate in a HIIT program is obviously recommended. HIIT results can be impressive with the authors citing noteworthy positive effects in as little as three weeks.

If we are looking for an aerobic target, the authors suggest considering the NFPA 1582 Standard on Comprehensive Occupational Medical Program for Fire Departments requirement that firefighters have "aerobic capacities equal to the 35 th percentile based on age and biological sex, subject to duty restrictions."

Generally, resistance training follows somewhat of a HIIT model where 'sets' consist of six to twelve repetitions followed by about 30 to 90 seconds of rest. Again, results can be impressive. Most firefighters would have an understanding of resistance exercising sufficient enough to be able to participate in a well-developed resistance training program. Specific mention is made of targeting areas that experience the most common injuries, i.e. the ankles, knees and back in order to improve strength in related muscles as well as balance. In one study cited, there was a 62% reduction in loss of time at work from injury, and a 42% reduction in overall injuries over one year for firefighters who participated in core strength exercising, although we should probably consider the Hawthorne Effect when evaluating these results. People will tend to modify their behaviour when they are being observed or studied.

Nutrition

The authors discussed nutrition in three topic areas – protein consumption, calorie restriction, and dietary supplementation, noting that the best meals have balanced macronutrients of fat, carbohydrate and protein.

The Recommended Dietary Allowance of protein for adults at time of publication of the paper was 0.8 grams per kilogram of bodyweight, but there is considerable research recommending higher rates. The International Society of Sports Nutrition (ISSN) recommends that adults who exercise should consume between 1.4 and 2.0 grams per kilogram. Dr. Michael Greger has disagreed, noting that we should be working with our 'ideal' weight, that the RDA was trying to capture variability across the population, and excess protein can have adverse effects, including disorders of the liver and worsening coronary artery disease. One of the corollary benefits of protein consumption, however, is in regulating weight due to increased satiety, and the metabolic processes required for digestion. In a firefighter fitness program, the value of increasing protein intake beyond the RDA is believed to be in maintaining and building lean muscle mass through muscle protein synthesis. The ISSN published a nutrition guide for tactical athletes in 2022.

The paper discusses caloric restriction in terms of using intermittent fasting modalities to achieve it, as opposed to traditional methods such as just reducing the size of meals, or changing the type of food – both of which should also be considered. It is generally believed that there are also metabolic, cognitive and immunological benefits to fasting.

Time-restricted eating involves limiting food intake to only a certain number of hours per day, typically about eight with a suggestion that the last meal be consumed a minimum number of hours before bedtime (often three). There are other fasting methods, including not eating for 24 hours or more.

In one study referenced in the paper, firefighters restricted to 10 hours of eating per day for seven weeks showed improved quality of life and cardio-metabolic health as well as weight loss.

Supplements may help, there is considerable research on the benefits of some supplements, especially Vitamin D, and it's highly recommended that vegans supplement Vitamin B12, and even Omega-3 fatty acids, but the authors note that, "firefighter performance after supplement or ergogenic aid consumption is understudied."

Most fire departments already have the equipment needed to implement effective HIIT and resistance training programs for firefighters on-duty. If not, it seems the research could support a cost-benefit case for supplying it.

The paper summarizes its work in a diagram that, in part, lists the performance improvements associated with nutrition and exercise benefits. These include; less likelihood to slip, trip or fall; greater time to exhaustion; improved functional movement and balance, and; increased alertness during stressful situations.

You can read the paper at this link: Strategies for Improving Firefighter Health On-Shift: A Review – PMC

See Greger on protein at this link: The Great Protein Fiasco: How Much Do You Really Need?