This article presents information that may be of interest to fire departments that can’t afford to conduct VO2 max testing as part of a firefighter fitness assessment.
Cardiorespiratory fitness in firefighters can be affected by metabolic syndrome (MetS), a cluster of conditions that occur together and increase your risk of heart disease, stroke and diabetes. Source: Mayo Clinic
Individuals with MetS have three or more of the following risk factors:
- Central (abdominal) obesity.
- High blood pressure.
- A high fasting blood glucose level.
- High blood triglycerides.
- Low levels of HLD (good cholesterol).
One of the ways that cardiorespiratory fitness is evaluated is through VO2 max testing. A VO2 max test shows the maximum amount of oxygen your body is capable of consuming to generate energy and measures your capacity to perform sustained exercise. A firefighter with a high VO2 max result is less likely to have MetS.
Unfortunately, VO2 max testing is not readily available to many fire departments because it requires sophisticated equipment and trained personnel to administer the test.
A team of researchers1 recently set out to see if a more accessible test involving resting heart rate (RHR ) and heart rate reserve (HRR ) could be a reliable predictor of MetS in firefighters. Here’s what they found:
What’s your HRR?
- Place your index and middle finger over your radial artery located on the thumb side of your wrist.
- Once you’ve found your pulse, count the number of beats for 30 seconds. Multiply this by two to get your bpm. Do this a second time and take the average.
- Calculate your max heart rate (MaxHR) by plugging your age into this formula:
205.8 - (0.685 × age). Example: A firefighter aged 52 would have a MaxHR of (205.8 – (0.685 x 52) = 170.18.
- Now calculate your by subtracting your RHR from your MaxHR (
HRR = MaxHR - RHR). Example: If this firefighter has an average RHR of 61 bpm, the HRR would be 170.18 - 61 = 109.18.
Learn more about this research
The research article is available through our library by contacting FEMA-NETCLibrary@fema.dhs.gov. Interested readers may be able to access the article through their local library or through the publisher’s website.
1 Choi, B., Ko, S., & Kojaku, S. (2017). Resting heart rate, heart rate reserve, and metabolic syndrome in professional firefighters: A cross-sectional study. American Journal of Industrial Medicine, 60(10), 900-910. doi:10.1002/ajim.22752
- Resting heart rate (RHR)
- Normal heart rate or pulse measured simply by placing two fingers over your radial artery and counting the number of beats in a minute. In this study, the researchers counted the number of beats per 10 seconds and multiplied by six.
- Heart rate reserve (HRR)
- The difference between your RHR and your max heart rate. Here’s a simple formula to determine your own age adjusted MaxHR:
205.8 - (0.685 × age). So for a 50-year-old, the MaxHR is: 205.8 - (0.685 × 50) = 172.