Are You At Risk For Heart Attack On the Job? Here’s How to Find Out.

Last week I discussed how important it is for firefighters to undergo regular fitness testing. Yet, not every department can afford to hire someone like me to conduct these tests. So I’m giving you a few simple tests to assess yourself. Click here to see how to test your own muscular fitness and flexibility.

Here’s how to assess your aerobic capacity using a running test.

Want a firefighter specific walking test? Scroll down to find out how to get it.

  • Start by walking on the treadmill for 3 minutes at a pace of 3.0 mph. This is a warm-up but counts toward your final time.
  • When the clock on the treadmill says 3:00, increase the speed to 4.5 mph.
  • At minute 4:00, increase the incline to 2%.
  • At minute 5:00, increase the speed to 5.0 mph.
  • Every minute afterward, alternate increasing the speed by 0.5 mph or the incline by 2%. The chart below shows the protocol, you may want to print it.
  • Run as long as you are able and record the time at which you stopped. Be sure to walk for 3 minutes to cool down.

Source: IAFF Wellness Fitness Initiative

How to interpret your resultsVO2max

Aerobic capacity is actually quantified by measuring a person’s maximal oxygen uptake, or their “VO2max,” in a research lab.

This test gives you a formula to predict your VO2max (+/- 3.7) based on the time you achieved on the protocol, and your size. You just need to do a teeny bit of calculation. Follow these steps to calculate your predicted VO2max:

1. Convert your time to number of minutes. For example, 12:30 would be 12.5 minutes.

2. Calculate your Body Mass Index (BMI):

If using metric system, BMI = weight in Kg / (height in meters)2

If using US units, BMI = weight in lb / (height in inches)2 x 703

3. Insert your values from steps 1 and 2 into this formula:

VO2max  = 14.821 + (time x 2.874) + (BMI x -0.242)


How good is your VO2max?

Research suggests that firefighters should achieve a VO2max of at least 42 in order to perform strenuous duties safely, without risk for heart attack. Firefighters with a very low aerobic capacity are at the greatest risk of experiencing a cardiac event.


How does your VO2max compare to others?

This chart shows how your aerobic capacity compares to the hundreds of firefighters I’ve tested over the past 7 years.

age VO2max
20-29 47.3
30-39 44.9
40-49 42.8
50-59 43.0


These charts show how your aerobic capacity compares to the general population.


Percentile age 20-29 age 30-39 age 40-49 age 50-59
90th 55.1 52.1 50.6 49.0
80th 52.1 50.6 49.0 44.2
70th 49.0 47.4 45.8 41.0
60th 47.4 44.2 44.2 39.4
50th 44.2 42.6 41.0 37.8
40th 42.6 41.0 39.4 36.2
30th 41.0 39.4 36.2 34.6
20th 37.8 36.2 34.6 31.4
10th 34.6 33.0 31.4 29.9


Percentile age 20-29 age 30-39 age 40-49 age 50-59
90th 49.0 45.8 42.6 37.8
80th 44.2 41.0 39.4 34.6
70th 41.0 39.4 36.2 33.0
60th 39.4 36.2 34.6 31.4
50th 37.8 34.6 33.0 29.9
40th 36.2 33.0 31.4 28.3
30th 33.0 31.4 29.9 26.7
20th 31.4 29.9 28.3 25.1
10th 28.3 26.7 25.1 21.9


Source: American College of Sports Medicine Guidelines for Exercise Testing

Want to assess your aerobic capacity using a firefighter specific walking test?

I created a maximal treadmill test that is scientifically validated to predict firefighters’ aerobic capacity and inform them if they’re at risk for heart attack. This test, which was published in a scientific journal, is much more representative of the job of firefighting than a running test. Firefighters walk briskly up an increasingly higher incline while wearing a weighted vest. It is very easy to learn to do and subscribers to my Firefighter Wellness Training get the instructions. Click here to learn more about my Firefighter Wellness Training.

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By | 2018-06-01T07:52:18+00:00 September 11th, 2013|Uncategorized|3 Comments

About the Author:

Dr. Karlie Moore has a PhD in Exercise Science and Nutrition and specializes in firefighter health. She has conducted fitness testing on hundreds of firefighters and has created the most comprehensive online wellness program for fire departments called the FitCulture program. Dr. Moore is also married to a firefighter and so understands their lifestyle and the health challenges associated with it.


  1. Stephanie Villeneuve September 23, 2013 at 2:29 pm

    I had my VO2 max done about a year ago on a treadmill (using the nose clip, gas analysis, etc.) and scored a 52. In doing the VO2 in the manner you have described, I score a 34. How come such a difference in numbers?

    • Karlie September 23, 2013 at 6:44 pm

      Hey Stephanie, there is an error margin of 3.7 when doing the predicted test but you’re right, it shouldn’t be that different unless your aerobic capacity declined a lot in the past year. Are you including your warm-up minutes in your final time? (you’re suppose to). If you want to send me your final time, height and weight to I will double check the numbers for you.

  2. Aaron Zamzow November 10, 2016 at 2:21 pm

    What test would you recommend for departments that dont have a treadmill or are trying to test big groups?

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