How Strong Is Your Engine?
A conversation I had with Dr. Chip Lavie led to this one: why your cardio fitness can say more about your health than your cholesterol, and two simple ways to find yours, a one-mile walk or a 12-minute run.
We tend to judge our health by the scale and by the numbers on a lab report. One of the strongest health numbers you can have is neither. It is your cardio fitness: how well your heart and lungs deliver oxygen while you work.
In a study of more than 122,000 adults who took a treadmill test, low fitness was linked to as much risk of death as smoking or diabetes, or more. In this article you will learn what that number is, why the cardiologist I interviewed ranks it so high, and how to find yours with one of two simple tests: a one-mile walk or a 12-minute run.
What Your Engine Number Is
I sat down with Dr. Carl "Chip" Lavie, medical director of cardiac rehabilitation and preventive cardiology at the John Ochsner Heart and Vascular Institute, and asked him why it is worth knowing your VO2 max as a starting point.
He told me VO2 max is the gold standard for measuring cardio fitness. It combines your heart, your lungs, and your muscles and tissues, getting oxygen to the places in the body that use it. It is the most oxygen you can take in at an absolute maximum effort.
Doctors do not require you to know this number, and most likely will not test you for it. But the number itself, Dr. Lavie told me, stands out:
"Knowing that the VO2 max is a gold standard of fitness, it's got the ability to predict prognosis better than almost anything there is."
Dr. Carl "Chip" LavieMedical Director, Cardiac Rehabilitation and Preventive Cardiology, John Ochsner Heart and Vascular Institute
He told me it is more important than your cholesterol or your blood sugar, and that it is critical for predicting heart disease outcomes, cancer outcomes, and even deaths from other diseases. Knowing it also tells you how you rank against people your age and gender. The American Heart Association has made the same case in a statement Dr. Lavie helped write: that fitness should be checked like a vital sign.
I have fun with it and ask clients how long they think they would last in a zombie apocalypse. It is important that we have this ability to push hard when we want or need to throughout life. You lose what you do not use, and one day you will lose your independence of movement if you do not take ownership of your engine.
You Do Not Need a Lab
The precise test is a cardiopulmonary exercise test, also known as a CPX stress test. You are linked to a 12-lead EKG and a breathing mask while being observed by a trained clinician. This test is used mainly by people in need of cardiac care and by the elite performance and tactical athletes I work with.
Dr. Lavie said most people in the world will never have that test, so there are other ways to estimate the number.
The two simplest are field tests you can do on a track this weekend. Pick the one that matches where you are starting from.
The Two Tests, Step by Step
If You Are New to Training: The Rockport Walk Test
The test was built and checked against lab measurements in 343 healthy adults ages 30 to 69. It is never an all-out effort, which makes it a test you can take at any fitness level.
- Find a measured mile. Four laps in the inside lane of a standard track is just under a mile.
- Warm up for a few minutes.
- Walk the mile as fast as you can hold. Walk, do not jog.
- Take your pulse the moment you finish. Count for 6 seconds and multiply by 10. Write down your time and your heart rate.
The full walkthrough, with a calculator: How to Take the Rockport Walk Test.
If You Are Already Training: The Cooper Run Test
Dr. Kenneth Cooper published the 12-minute run in 1968, and it is still a standard field test for people who already train. It is an all-out effort, which is why it is not the place to start if you are new to training or cannot run a full mile yet.
- Warm up well. This one is an all-out effort.
- Run as far as you can in 12 minutes on a track or a flat, measured route.
- Write down your distance.
The full walkthrough, with a calculator: How to Take the Cooper Run Test.
If you are part of Fit Fête, both tests are already live as challenges in the app: The Rockport Walk Test and The Cooper Run Test. Each one walks you through it and does the math for you.
Coach's Note: The Rockport Walk Test is for people new to training or who cannot run a full mile yet. The Cooper Run Test is for people already training.
What Your Number Tells You
Either test turns into an estimate of your VO2 max if you want it: Rockport calculator or Cooper calculator. Each one also rates your result against people your age and sex.
Here is the part people miss: you do not need the lab number to see progress. If your mile gets faster and your finish heart rate gets lower, your engine got better. If you cover more ground in the same 12 minutes, same thing. Retest in 8 to 12 weeks of consistent effort. Your fitness can start improving within a few weeks, and by then the change is often big enough to show up in this number.
If you do not rank well, Dr. Lavie said, there are ways to improve. That usually means being more physically active and doing more exercise training. Many people can help their fitness just by meeting the activity guidelines: getting off the couch, getting out, even walking thirty minutes on many days. Almost everybody's VO2 max falls with age, he told me, but regular activity can prevent a lot of that fall.
Before You Test
If you have a heart, lung, or kidney condition, diabetes, or chest pain or dizziness with activity, check with your doctor before either test. If you have a joint condition or have been inactive for a while, check with your doctor before the all-out run. Start with the walk.
How to Take Your Test
- Pick your test: walk or run.
- Do it, and write your numbers next to your photos and your daily burn.
- Put a retest date on the calendar, 8 to 12 weeks out.
Built & Balanced
If you want a plan to build on your number, Built & Balanced is my six-week program for busy adults and anyone getting back into training: four workouts a week, about an hour each, in the MaxWell Nutrition app. It comes with MaxWell Nutrition Unlimited.
The scale tells you what you weigh. This number tells you how well your engine runs. Pick your test, walk it or run it, and write the number down. In 8 to 12 weeks you will have something better than a guess: your number against your number.
Take your test: The Rockport Walk Test or The Cooper Run Test.
Spencer Maxwell Shilstone
Founder of MaxWell Nutrition and Shilstone Performance Systems. Spencer works with teams and individuals to help them reach their performance goals. He has the honor and privilege of working with and building integrative performance programs for members of U.S. Army Special Operations Command. Optimum Performance is his column at MaxWell Nutrition.
