Should Fitness Be A Vital Sign?

The skeptical cardiologist routinely probes his patients’ activity and exercise levels and encourages them to engage in 150 minutes of moderate exercise weekly. However, I’m somewhat skeptical of the benefit of treating such assessments as a vital sign (like blood pressure or heart rate)  as a recent AHA scientific statement suggests.

I can only envision still another item  on a chart checklist that will have to be recorded in the EHR or already over-worked physicians will have their payments withheld.

The AHA statement suggests that ideally we should be measuring  our patients’ fitness by obtaining  maximal oxygen consumption (VO2 max) utilizing an expensive and rarely utilized cardiopulmonary exercise test. Failing that we should consider doing a treadmill stress test. Failing that, rather than utilizing my simple question to patients: “How active have you been?”,  the statement recommends doctors utilize some sort of formal questionnaire to estimate their patients’ cardiorespiratory fitness (CRF) such as the one at World Fitness Level.

I went online to take this CRF estimator (based on this paper) and I remain skeptical.

The online site and  a free smartphone app both ask the following questions:

  • Country and City
  • Ethnicity
  • Highest Level of Education
  • Gender/Age/Height/Weight
  • Resting and Maximal Pulse
  • How often do you exercise?
  • How long is your workout each time? (over/under 30 minutes)
  • How hard do you train? (I had to choose between “I go all out”or “Little hard breathing and sweating”)


screen-shot-2016-12-03-at-11-33-13-amWhen you have finished answering the questions you are given an estimate of your fitness age. When I did this online a few days ago and answered truthfully I got the result to the right: I had the fitness of a 41 year old with an estimated VO2 max of 49 ! (interestingly this estimate corresponds exactly with VO2 max derived from a recent stress test I completed.)

I used the app (which unlike the online version did not ask me my waistline measurement) and changed a few parameters:

  • I increased my resting heart rate or pulse  from 60 to 68 beats per minute (BPM)
  • I increased my maximal heart rate from what I know is 158 BPM to what the app calculated (173 BPM, which makes no sense)
  • I switched from exercising 2-3 times per week  and longer than 30 minutes  at “all out” level to the lowest level for all 3 questions.

The change was dramatic and depressing: I went from 39 years old to 67 years old in the bat of an eyelid!img_8073




The app and online site direct you to a non-profit site where you can get information on a 7 week program to increase your fitness level. I haven’t checked this out.

I’ll be trying out this CRF estimator on my patients: assessing whether it adds anything to my usual line of questioning on activity and fitness.

I encourage you to give the CRF estimator a try. Let me know in the comments how you feel it works for you. Does it motivate you to exercise more knowing that, for example, your fitness age is substantially higher than your chronological age?

17 thoughts on “Should Fitness Be A Vital Sign?”

  1. I tried it, but I didn’t know my maximum heart rate and the choice between “I go all out” and “little hard breath and sweating” did not seem appropriate because I wanted something in between those two options. The answer it gave me, which was the same as my actual age, did not seem right because I know I am more active than most people my age. I work out for about 45-55 minutes about 5 days a week, which is far beyond the average person (although still probably not enough).

    I do think my internist should ask how much I exercise. When I have tried to raise the topic, he immediately interrupts me and shows no sign of taking what I say seriously.

    1. Marilyn, thanks for your comments. I had the same issue in choosing “all out” versus “little hard breathing and sweating”. I’m not even sure what ” I go all out ” means but I preferred it to “little hard breathing”.
      I have to investigate what they mean by your maximum heart rate. It is confusing because we predict patients’ maximal heart rate on the treadmill as 220-age. They seemed to be using 235-age when they calculated it for me. Most patients will probably opt for the rate calculated by the app.
      Doctors like your internist are probably the reason the AHA feels compelled to make fitness a vital sign-mandate measurement because it is not being done universally.

  2. This was very enlightening. I had thought that measuring fitness was a good idea until you provided the perspective of the doctor who actually has to implement this test. I think when stuff is proposed that doctors should do, like this and EMRs to name two examples, no one ever asks the doctor.

  3. I’m 62 and the data I entered said I have the fitness of an average 37 year old but my actual fitness level is 49. Like you Dr. Pearson, I fall between “I go all out” and “little hard breath and sweating” but chose “I go all out” because I feel like I’m closer to that level of intensity and frequency of excercizing.

    I think this is an additional way of assessing ones health in much the same way as taking a blood pressure reading but I think the questionnaire definitely needs some tweaking.

  4. I tried the calculator and it said I had the fitness level of an under 20 year old. Since I am over over 40, I am dubious about that determination. I do ask patients about fitness but won’t be using the calculator.

  5. I have run a steady 15-20 miles a week, week in and week out, since 1985. I have also been told I have “high cholesterol” since 1988, and have been “encouraged” to take a statin more than once by my current primary care physician. My HDL at last measurement was 63, my triglycerides 88. As far as I know, he has never tested the composition of my LDL. I also took a stress test in 2009 after an insurance company tried to deny me insurance and was told I am at low risk for cardiovascular disease. So the statin is not going to happen.

    Given the recent doubts about the accuracy of the 2013 risk calculator and plenty of peer-reviewed evidence that high rates of fitness are clearly a factor in inhibiting the onset of heart disease, there should be better quantification of fitness in the overall scope of health status. This announcement is a good first step in convincing clinicians of that.

    1. Greg, let me make a few points about your comments.
      1. If you have inherited a predisposition to premature atherosclerosis it is likely that despite your best efforts at keeping a high level of fitness by running regularly (and following a really healthy diet) you will still develop significant plaque in your arteries at an early age and be at risk for heart attack and stroke (see my post on “dealing with the cardiovascular cards you’ve been dealt”). Jim Fixx, the runner who did much to initiate the fitness craze in the US dropped dead during a run and had advanced triple-vessel CAD at autopsy.
      2. The best way to figure out if you have inherited this predisposition to premature atherosclerosis is with a coronary calcium scan which I’ve written about a few times on this site and which Chris mentions elsewhere in the comments.
      3. Despite absence of symptoms while running and excellent stress test results, advanced plaque can be present and you can be at risk of sudden cardiac death ((

      1. Thanks for your thoughts, Doctor! As far as I know, there is no premature atherosclerosis in my family. My Dad is 88 and still walks a mile every day, two of his three brothers died at 86, and none had a heart attack. My maternal grandfather lived to 77, and also had no cardiac issues.

        I actually suggested a calcium scan to my primay care physician, who dismissed it as a “scam,” equating it with the carotid scans often given out at senior centers that are not covered by insurance. He continues to get his knckers in a twist over LDL in the 140-160 range, and I am not buying the statin thing on that alone with an HDL of 60+ and triglycerides that range from 88 to 150, let alone the contrarian research. In interest of full disclosure, I do take 20 mg of Lisinopril daily that keeps my BP in the 120/70 to 130/90 range.

        I’m almost 60, and, as Errol Flynn said, been everywhere and done everything twice. I feel hale and hardy, I’ll take my chances with life as I live it – including my daily run, bike ride, or morning on skis.

        1. That’s great on the family history or lack thereof.
          I am very sensitive to scams. Coronary calcium is a very legitimate method for assessing subclinical atherosclerosis. A zero score in you for example and you could tell your PCP to lay off the statin talk. The carotid and other vascular scans are used in a profit-centric method (I’ve written about that a few times) by Life-line and their ilk. But for most of us ordering coronary calcium scans the scanners are in the hospitals and there is no conflict of interest.

  6. I could have carbon copied Gregs reply except for a couple of changes. As a “victim” of genetically high LDL levels, I made the decision to fight off heart disease by adhering to a squeaky clean lifestyle and 200 plus miles a week on my bike in the Santa Monica mountains of So Cal. I even had the LDL composition measured which favored the “good” particle size. Dr. P just started me on my first Statin medication following a very high score on my coronary calcium test at age 54. Exercise will always be an important part of my life, but certainly didn’t prevent my heart disease. But, who knows how advanced the atherosclerosis would be if I hadn’t been so fitness obsessed.

  7. The prerequisite for anyone who wants to live – and age – in health and in top form is to have every aspect of their bodies working efficiently. All aspects are interrelated. You can’t expect a brain that’s not supplied with a strong and supple cardiovascular system to be sharp, clear, and creative.

    Of course fitness is vital.

    Is it a sign? That’s tricky. What is fitness? You must use your body to stimulate it to serve you better, but, as with most goals, it can be overdone. It can be underdone. There’s a Danish study that looks at more than seventeen thousand subjects divided into those whose jobs require very vigorous physical activity, vigorous activity, and those whose activity is recreational. Very vigorous got the most atrial fibrillation, vigorous got less, and recreational got no measurable difference. (This study didn’t look at the sedentary, but WE know they’re at risk.)

    Fitness or not is a consequence of lifestyle, not a two month gym course, not a matter of falsifying a questionnaire to get your doc off your back 😉 not a matter of becoming a body-builder or Olympic contender. It’s not even a matter of developing a routine that works and sticking with it. This is because the human body accommodates so nicely. One’s body becomes very efficient at repeated maneuvers such that doing the same routine over time has diminishing effect. You actually lose fitness. Even by simply walking unvaryingly. One must vary according to one’s developing Life. Ruts get you nowhere, whatever the rut.

    Concerning measuring fitness:
    It depends. I have overdone. I acquired AF in my fifties. There’s no question that some are more susceptible than others. (I wish that I could ever have done what Jack LaLanne did for his routine a couple of days before he died in his nineties) As a consequence of my ablation(s), my resting heart rate went from the high fifties to the low seventies. (Do you have a perspective on that phenomenon, Dr. Anthony?) My stressed heart rate is unpredictable. So, that is pretty worthless as an indicator for me. I just have to work my body in the ways that result in my feeling good – pressing a bit, but recognizing what constitutes overdoing. Being very strong when you’re younger has advantages, but the strains of getting there can show up as the disadvantage of damage in age.

    Hopefully, with more insight through increased knowledge (And your blog!), people can be smart about this without the perspective of age and the results of having overdone.

  8. I’m sure Dr. P told you, but statins will increase your coronary artery calcium score. And what does that mean? (Good conversation starter.)

    1. When asked about the utility of follow up coronary calcium scans I tell patients that despite statin therapy the calcium score will go up. But, recent studies suggest this is a good thing as the calcium deposition appears to be a marker of plaques “healing” and transitioning to a condition that is less “vulnerable”, less likely to rupture and cause heart attack.
      We can anticipate that the overall burden of atherosclerosis in the arteries will decline and definitely stop advancing with statin therapy but calcium scores will advance.

  9. This calculator is completely useless and wrong. I’m in better shape and have more strength then guys half my age. I will be turning 40 this year. The calculator showed me being older than I am. Just as the BMI can’t always determine everyone’s fitness neither can this test. You have to take in consideration all aspects. Muscular build, bone structure, endurance, etc. Don’t ever waste your time with this crackpot world fitness calculator

    1. It’s a good question. Recent data suggest long-term exposure to really high levels of endurance exercise is associated with increased coronary calcium. Usually this implies increased CAD risk.
      However a recent study on exercise and coronary calcium (Arnson, et al, JACC),found that the higher CAC scores in these types was not associated with higher mortality.
      thus, the higher CAC in high-level runners may represent an adaptive rather than a pathophysiologic response.
      More studies needed!
      With respect to atrial fibrillation, there is reasonably good evidence for a five fold increased risk of AF in high level endurance athletes. I see that a syndrome has been coined for this: ‘PAFIYAMA’ (‘paroxysmal AF in young and middle-aged athletes’). We don’t yet know the reason for this or the consequences.Here’s an idea I just had… Despite improved diastolic function/stiffness when you run really fast, left atrial pressure goes up with increasing heart rate and reduced diastolic filling time and this may over time cause LA remodeling and subsequently AF.

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