Physical Fitness: More than Your BMI

Did you know that physical fitness is so important to your health that the American College of Cardiology recommends that it gets measured annually at a preventive visit as a “vital sign?” Physical fitness has been shown to be linked not only to the risk of getting sick, but to the risk of dying once you get sick. Physical fitness is a different parameter than BMI. Some people erroneously assume that a person’s physical fitness level inversely correlates with their BMI, or the lower the BMI, the higher the fitness level. However, that is not a correct assumption. The recognized relationship is that a person’s physical fitness level correlates with their lean body mass, or, the higher the lean body mass, the more physically fit. It is also sometimes assumed that if a person is active, they are physically fit, but that is also not always true. Physical fitness means how well your heart and vascular system can pump blood and your body can extract oxygen from that blood. While part of it is genetic, it is also modifiable and trainable. So, if it is so important, how do you know what yours is and how do you improve it?


Measuring Physical Fitness at Home

You can measure your fitness at home a few ways. As always, don’t hurt yourself trying this at home! If you have been advised by your doctor to limit your activity, then consult with your physician first. And, it is always advisable to start at a low physical activity intensity level and progress things at a reasonable pace and stop if you are concerned. However, overwhelmingly the studies show it is safer to exercise than not to exercise. And, call 911 if you think you might be having a heart attach or stroke!



Resting heart rate

Your resting heart rate can given an estimate of your physical fitness level, although it is not always accurate and there are various things that can affect it. In general, the more fit you are, the lower your resting heart rate is. However, things that are sources of error in this are medications, dehydration, anemia, fever, or other things. A normal resting heart rate is 60 to 80 beats per minute. Very physically fit people may have resting heart rates closer to 50, and physically unfit people may have a resting heart rate between 80 to 90.


Wearable Technology

Some wearable technology, like fitness watches, will give you an estimated “VO2 max”. A VO2 max is somewhat of the gold standard in reflecting physical fitness. It is the amount of oxygen your body extracts per liter of blood per minute per kilogram. The watch calculates it by measuring your heart rate and correlating it to the intensity of your exercise. For example, if you run 3 miles in 36 minutes and your heart rate is 130, it will give you one VO2 max, whereas if you run the same 3 miles in 24 minutes and your heart rate is 130, it will give you a higher VO2 max. The technology will usually also give you a range to reflect if the VO2 is average, below average, athletic, or elite.


Home Fitness Test

A home fitness test is a test that you can perform on your own at home and it takes about 10 minutes. Again, refer to the warning above! We used to perform these at Rainier Medical Health & Fitness exercise facility, and people would say that it was helpful to them to do this, either because it was better than they thought, or worse than they thought and made them realize they need to change their routine, or because they realized it was an easy way to get some aerobic exercise at home. Here are the steps and a link to a video on how to do this at home:


STEP TEST PROCEDURE


Video Link


Here is a video link on how to do the test:

Step Test Video


Purpose

Inactivity is one of the major risk factors for Coronary Artery Disease (CAD). In fact, numerous studies have shown that it may be the most important factor responsible for CAD. Consequently, exercise reduces the risk of dying from a heart attack. Other benefits of exercise include improving circulation, lowering high blood pressure and triglycerides, increasing good cholesterol, and helping control weight.


Definition

The Step Test is designed to measure a person’s aerobic fitness. The test measures your cardiovascular fitness by evaluating your heart rate recovery after a short bout of cardio exercise. In essence, the lower your heart rate, the better your cardiovascular fitness. Participants step up and down, on and off an aerobics- type step for THREE minutes to increase heart rate and to evaluate the heart’s recovery rate during the minute immediately following the step test exercise.


Precautions:

Do not perform or stop if you have:

  • High blood pressure: systolic pressure > 160 mm Hg OR diastolic pressure > 100 mm Hg

  • chest pressure, chest pain, lightheadedness, dizziness, unexpected shortness of breath or any other concerning symptom

  • any other reason to want to stop

  • severe fatigue


Test Equipment

To conduct an accurate test, you need the following;

  • A 12-inch tall step (you can use a box or a step too, but it should be close to 12 inches)

  • A stopwatch or timer

  • Metronome

Metronome for apple

Metronome for android


  • A partner to help with counting.

 

Pre-Test Considerations

Test accuracy affords a more candid interpretation of the test results. For maximum accuracy. ensure that you are not on any medication before taking the test as this may affect your heart rate. Also, avoid caffeine drinks such as coffee and energy drinks at least 3 hours before conducting the test. Caffeine beverages can increase your heart rate leading to an inaccurate result interpretation.

Also, do not conduct the test if you have any knee or ankle injuries as this affects your pace while doing the exercise.

Please avoid doing this test if you have any specific cardiac (or other known medical) condition until you have been cleared by a supervising medical professional.

 

Performing the Test

The goal is to step on and off the 12-inch box or bench for 3 minutes continuously while maintaining a uniform pace and then evaluating how fast your heart rate will recover.

Here’s the full procedure:

  • Start by setting the metronome to 96 beats per minute. Ensure its audible so you can hear each beat.

  • Once set, start your timer and begin stepping on and off the step to the metronome beat for 3 minutes. Ensure you maintain a consistent pace and do not stop to catch your breath during the test.

  • When the timer clocks 3 minutes, stop the routine and sit while maintaining an upright posture. Record your heart rate for 60 seconds counting each beat. For more accuracy begin recording as soon as you can after stopping the exercise.

  • Evaluate your result with the age-adjusted evaluation table.  The ratings on the table are broken down by excellent, good, above average, average, below average, poor and very poor.


Interpreting Results


Look for your heart beats in your recovery window here.


How to Improve Your Results

To be honest, most us find ourselves on the wrong end of the table. However, you can gradually improve your test score as you work your fitness levels.  The 3 minute step test is based on your endurance levels. This means you will need to invest time in doing cardio exercise.

For starters, come up with a daily cardio workout.  For example, you can choose a morning run on the treadmill or cycling. Start small on your workout plan; you don’t have to run a mile on your first day. The goal is to keep bettering your best each day with your workout plan.

If you are diligent with your plan, you will notice a gradual improvement with your endurance levels. Get back to the test and evaluate your progress, and keep at it until your numbers score in the excellent zone on the table.


Clinical Importance

Many people look at their BMI to assess their health risks. BMI does correlate with health risk, but it is only one piece of the puzzle, and provides an incomplete picture. I am frequently recommending a comprehensive view, including waist to hip ratio, blood pressure, resting heart rate, blood work results, and physical fitness. The number of steps you take a day does not indicate your physical fitness. So, think about assessing your fitness to get a more complete picture. And, remember, at any weight, the more fit you are, the lower the risk of developing cardiovascular or metabolic disease and even dementia, and the higher your chance of doing well if you get any disease, injury, or health condition.


Take Back Your Fitness,


Valerie Hope Sutherland, MD



Hiking at 13,000 feet takes a high level of fitness!

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