Rethinking Cardio
The current mainstream thought in the fitness industry is that cardio is king. Large chain gyms fills most of their available real estate with elliptical machines, Stair Masters, trend mills, and rowers. Cycling as a sport, pastime, and form of transportation has never been more popular. We view the height of athletic achievement as the adventure race, local 5k, marathon, or ultra-marathon. Many prefer a higher intensity form of cardio as evidenced by the proliferation of classes like HIIT, spin, cardio kick-boxing, and even CrossFit. While the mainstream ideals are shifting to emphasize strength training as well, the idea persists that optimal health and longevity follow a highly developed cardiovascular capacity.
It is safe to say that we have a cardio obsession.
Where Does Our Cardio Obsession Come From?
In the late 1940s and early 1950s a trend of increased heart attack and stroke emerged. This trend is no doubt linked to the industrial food movement that arose from the post-WWII industrialization. Many agencies arose to address this raising epidemic including the American Heart Association in the United States and the Medical Research Council in Great Britain. A landmark study from this era known as the London Transport Workers Study began to shape the understanding of this issue. The study compares the rates of coronary heart disease (CHD) in drivers and conductors of the London Transport Executive. All subjects were men between the ages of 35 and 65, had nearly identical working hours, but quite different work duties.
The drivers remained seated for much or all of their shifts while the conductors remained in motion nearly all of theirs. The conductors where required to board and exit the trains, trolleys, and buses, walk up and down the aisles and double-decker stairways, and remain standing while riding. The study found reduced incidence of CHD in the conductors and less severity in the cases of CHD that they did find.
These findings led to further epidemiological studies of other occupations, all confirming the fact that humans who move more have a lower incidence of CHD. What a novel idea…
So, how did these studies lead to our cardio obsession?
Follow up studies through out the rest of the Western world sought health markers that they could isolate and measure to quantify the health of the individuals that they were studying. Enter all the measures of cardiovascular capacity that we know today: heart rate, stroke volume, blood pressure, etc.
The studies presented findings correlating measures of these factors with reduced risk of CHD and improved overall health and longevity. As we so often do in the Western world, people understood these findings to mean that healthy measures on these test were to source of good health, rather than symptoms of it.
This line of thinking is akin to a student studying only material that will only be on the final exam, rather than working to achieve a comprehensive understanding of the course subject matter.
Training to improve upon these several measures of cardiovascular function expresses an extremely narrow view of health. A good score on the test doesn’t necessarily mean a vast understanding, but a vast understanding will always lead to a high score. Analogously, strong health from constant movement will lead to strong measures of health markers. Training specifically for the markers does not guarantee optimal health.
How We Got It Wrong
The prevailing lesson from these studies ought to have been that people who move more and stagnate less are healthier, as evidenced by their measures of many health markers and their rates of heart disease. Instead, we sought to change nothing about our lifestyles and working conditions and simply adapted our minimal movement practice to improve a few measures of cardiovascular function.
The Western world has an over-mechanized view of the human body. We tend compare ourselves to machines, understanding our various systems as analogous to the mechanical systems we build. The obvious example when it comes to our cardiovascular system is a comparison to a pump and network of pipes.
While this model provides a basic understanding, it fails far short of providing a framework to understand how to optimize our cardiovascular health. This analogy places a heavy emphasis on the heart as the sole driver of circulation, with the veins, blood vessels, arteries, and capillaries simply as static pipes through which the heart pushes blood. Our cardiovascular system is far more complex than this model suggests.
The pump and pipes model developed because the activity of the heart is easy to measure. Think how quickly and easily your heart rate and blood pressure are taken at the beginning of each visit to the doctor. The heart’s activity exists on a macro enough scale to lend itself to easy measure.
Measuring the activity and flow through the various other parts of the system remains far more difficult. We can measure the flow through some of the larger passages of the cardiovascular system, but the flow through blood vessels happens one cell at time, like a single-file line marching through a narrow doorway. To measure this flow you would need to be in the blood vessel itself.
Our heart-centric model negates the dynamic nature of the vascular network and the important role it plays in circulation.
A New Cardio Model
I propose a new way to imagine our cardiovascular system. Rather than a large central pump and a network of static pipes, think of your tissue as sponges. Muscular contraction and relaxation drives local circulation. Contraction flushes out spent fluid and blood like squeezing out a sponge. Muscle elongation or relaxation draws in fresh blood and fluid to oxygenate and hydrate the tissue.
Movement drives the entire process. A strong heart ensures the entire system runs cohesively, but local contraction and relaxation drives the specificity to where the oxygenated blood actually absorbs.
To rinse out a sponge hold it under running water and continually squeeze and release until you have flushed out everything. Simply holding it under water will do little to flush the entire sponge. Our tissue functions largely by the same principle.
Sitting on a bicycle is certainly better than no movement at all but it is incomplete as a sole form of exercise. Leaving the limited, linear, repetitive range of motion and poor posture aside, cycling uses little more than the large muscles in the upper legs. It is a valid form of movement but understand that it does not achieve the true goal of “cardio”: to create fully systemic circulation to re-oxygenate as much of your body tissue as possible.
Increasing your heart rate will pump blood through the larger passages of your whole body. This blood will not enter any tissue unless it is specifically called. In the cycling example, blood is really only called to the large muscles of the upper legs. The upper body very obviously remains uninvolved, but even the lower legs and feet have minimal roles in cycling. The calf remains engaged to keep the ankle largely static to most efficiently transfer power from the upper leg through the foot and ankle to the pedals, yet cycling requires little to no movement of any joints and tissue below the knee. Cycling, while raising your heart rate, is mostly sedentary except between the hips and knees.
Rethinking Cardio
Understand that your cardiovascular system consists of a cardiac system and a vascular network. Your cardiovascular system is meant to be used as a whole. Seek dynamic, fully body, creative movement to drive circulation to the unfamiliar corners of your system.
Muscular activity not only brings circulation into individual tissue but aids in systemic circulation by pushing blood along with each contraction and drawing it forth with each elongation. Each cycle of muscular contraction and elongations is a small pumping action that drives overall circulation. Elevating your heart rate without the corresponding aid to circulation from your vascular system adds additional stress to your heart. This is analogous to running a main pump all out while leaving any smaller secondary pumps turned off. We see a high correlation between endurance sports and atrial fibrillation, but that is a topic for another article.
I believe it extremely important to strengthen your heart but using your system as a whole remains far more important. Understand that short (or long) bouts of exercise to elevate your heart rate cannot undo the effects of a sedentary lifestyle.
This article is as much a case for movement as it is an examination on the cardiovascular system. Your entire body and all of it’s wonderful systems require constant movement for optimal function. Most of us have heard the tale of sharks whom must always remain in motion to drive circulation of water through their gills. Think of your systems the same way. Movement drives the operation and dictates the function of all your wonderful biological systems.
The over-mechanized view of our bodies leads to the idea that our cardiovascular system (and many other systems) can be trained in isolation for optimal function. Nothing could be further from the truth.
Ancient Greek physician, Paracelsus understood the holistic nature of our bodies’ optimal function when he claimed “There is but one disease in the body and its name is congestion.”
A New Form of Cardio
The value of a movement does not lay in how much it makes your sweat, elevates your heart rate, makes you feel sore, or achieves “likes” on social media. Learn to value your movement choices by how much of your body they require, how differently they load your tissues, and how well they challenge your entire system including your mind. Crawling on the ground using as many different crawl variations as you can dream up rates much higher by this standard than nearly every piece of gym machinery that you could use. It requires whole body engagement and awareness, will drive circulation to nearly every tissue, and challenge your body in a completely unique way. If you still feel the need to spike your heart rate just do it fast and non-stop. I can think of few exercises more exhausting than freestyle crawling for 10 minutes straight.
Change your priorities from blasting your heart rate to exploring new movement patterns. The possibilities are endless and each movement session becomes an opportunity for creation.
Avoid stagnation in every form. Seek constant motion and creative, dynamic movement.
Keep moving if you want to keep moving forward.