Investing in cardiopulmonary exercise testing is an investment in health, longevity, and overall safety

By Nick Perkins

It’s no secret we face intense physical demands that require peak cardiovascular and pulmonary health to do our jobs safely and effectively. Cardiopulmonary exercise testing (CPET) is a critical tool for assessing these functions and ensuring we’re prepared for our roles.

Compared to traditional stress tests, CPET offers more comprehensive insights, particularly regarding oxygen uptake and heart-lung function, which are crucial for survival on the fireground. The problem in the fire service is that routine exercise stress tests, which do not account for gas exchange, fail to identify early pathology and, in some cases, grossly overestimate aerobic capacity in high-risk populations.

A brief history of cardiorespiratory exercise testing includes the development of methods to measure cardiorespiratory fitness (CRF) and the development of cardiopulmonary exercise testing (CPET):

  • 1920s: British physiologist Archibald Hill proposed the relationship between physical activity intensity and the maximum rate of oxygen uptake by body tissues, coining the term VO2 max, the primary measure of CRF
  • 1929: Master and Oppenheimer published a paper using systolic blood pressure and pulse rate to estimate cardiac capacity
  • 1938: The American Heart Association recommended adding a precordial lead to the three limb leads of Einthoven
  • 1949: Robert A. Bruce and colleagues began testing patients on a treadmill
  • 1960s-1970s: Drs. Wasserman and Whipp at Harbor-UCLA developed CPET
  • 1989: Blair and colleagues published a study estimating fitness using maximal treadmill testing in more than 13,000 men and women, finding the lowest mortality rates among the most fit and highest among the least fit
  • 2016: The American Heart Association published a scientific statement advocating that CRF be categorized as a clinical vital sign

Today, research highlights that CPET can predict risks of heart disease and sudden cardiac events, both of which are leading causes of firefighter fatalities. A study published in the American Journal of Obstetrics and Gynecology emphasizes that CPET provides superior evaluations of cardiac and pulmonary capacities compared to standard exercise tests.

Early Detection and Intervention

Fire chiefs should make CPET an annual requirement for their firefighters. The goal is not to remove individuals from service or be punitive, but to identify those at risk early and provide the necessary resources to address these risks. The good news is many of these risk factors are modifiable, and fitness prescriptions, such as Zone 2 training – a brisk walk performed at a pace where talking becomes difficult – can help improve firefighter health and performance.

The challenge with Zone 2 training is the time commitment. At least 120 minutes per week is recommended, ideally broken into two 60-minute or four 30-minute sessions. According to Dr. Iñigo San-Millán, at least 45 minutes per session is required to gain mitochondrial benefits.

While this may seem daunting, even 20-minute blocks of training provide benefits. It’s important to fit in what you can. I stress this because, as fire chiefs, we can also fall behind in taking care of ourselves, but scheduling Zone 2 into our work week can be a great way to get started. I personally knock out one of my 60-minute sessions with one of my assistant chiefs and use that time as our weekly one-on-one meeting, as well.

Implementing CPET

CPET can be integrated into your existing annual medical exam. Talk to your provider about how to best implement this. This could involve contracting a vendor or directing your existing provider to invest in offering the service. That’s the route we took within my fire department, and to their credit, our vendor went all in. We have been using CPET as part of our annual physicals for almost five years.

During that time, we’ve learned a lot and are in a better position to focus our efforts on those who need the resources. We also have a good sense of our collective cardiorespiratory health as a workforce.  Soon, if not already, VO2 max, CPET, and Zone 2 training will be common language in the fire service. It’s not too hard to imagine that your newer, younger firefighters will expect this type of evaluation and feedback (their VO2 max and how to improve their specific numbers).

Safeguarding Lives

Investing in CPET for firefighters – and ourselves – is an investment in health, longevity, and overall safety. This is a key step in ensuring our personnel live long, healthy lives, well into retirement.

Losing a firefighter to a line-of-duty death is a tragic event that causes significant trauma to the firefighter’s family, friends, colleagues, and community. With sudden cardiac death being a leading, preventable cause, it is up to us to use these available tools to reduce this risk. In doing so, we help create healthier, more capable firefighters.

As fire chiefs, we face numerous challenges, including budgetary constraints. However, not investing in firefighter health is more expensive over time. Just as we invest in equipment and infrastructure, we must prioritize the health of our firefighters. Firefighters give their all to protect others – let’s ensure they have the tools to protect themselves, too.

Fire chief Nick Perkins has served as a firefighter with ESD 2/Pflugerville Fire Department since 1998. He holds an MPA from UT Rio Grande. He has a history of developing industry leading community, training, health, and safety programs.