Are you cardio fitness fit?
A simple question with a complex answer. Cardio fitness refers to our body’s ability to take in, transport, and utilise oxygen through our bloodstream while exercising. And while it is, of course, hugely important for professional athletes, what about the rest of us? How does being cardio fit or unfit impact our overall health?
Quite simply, the fitter we are from a cardio perspective, the more oxygen we can draw into our lungs, which is then pumped around the body via the heart and blood vessels to be made use of in our muscles. As our CV fitness improves, so too does the body’s ability to carry out this process.
It’s actually quite fascinating just how “cardio fit” someone can become. At the extreme end of the spectrum, CV fitness indeed allows people to achieve incredible feats of athleticism and endurance. Take famed endurance runner Dean Karnazes who has been able to run 350 miles in 80 hours, secure several Top 5 finishes in the Badwater Ultramarathon (a 35-mile endurance race across Death Valley in 120°F heat), and complete a marathon-a-day for 50 days back-to-back.
Now while we certainly don’t need to reach those superhuman heights, we should all be aware that maintaining a certain level of CV fitness is key for our health, as it is linked to a long list of benefits, from lower blood pressure and weight loss to a reduced risk of heart disease, diabetes, respiratory problems, and much more.
Inside a cardio fit body
What exactly does cardio fitness look like? What changes occur inside our body as we improve our fitness, and what is the end result?
For starters, cardio fitness comes about as a result of regular cardiovascular or aerobic exercise – that’s essentially anything that gets the larger muscles of the body working and gets blood pumping rhythmically around the body – such as running, cycling, swimming, crossfit, etc.
The first major organ to see the benefit of improved CV fitness is, as you’ve probably guessed, the heart. When we exercise, blood flow is directed towards the muscles that are being worked, while drawing blood flow away from those which are not. This results in increased blood flow and volume of blood within the heart muscle.
Over time, as the heart regularly registers this increased flow and volume, it strengthens and enlarges, allowing the muscle to hold and eject more blood per beat. Thanks to its new increased capacity, the heart no longer has to work as hard to push blood around the body – both when exercising and during rest periods. Essentially, cardio fitness improves your body’s ability to distribute blood to your muscles by stimulating the production of new blood vessels, leading to more efficient circulation of oxygenated blood.
There’s good news for the lungs, too, as high levels of cardio fitness improve their ability to oxygenate the blood that flows through them as we exercise. Essentially, the fitter we are from a CV standpoint, the faster and more effectively our lungs become at loading oxygen into our bloodstream. The faster we can utilise this oxygen, the quicker it reaches our muscles and tissue and the longer we are able to endure periods of exercise. As with the impact of cardio on the heart, this improved lung function also results in greater performance during periods of rest, which is why those who are cardio-fit are rarely left breathless when carrying out everyday tasks such as climbing stairs.
These two factors combine to create a body that is incredibly proficient in providing our working muscles with oxygenated blood as soon as they need it. What’s more, as the efficiency of our lungs and the volume and strength of our heart increase, so too their workload decreases – improving both stamina and endurance.
A long-distance runner is again a great example of this in action. If we look at British distance runner Mo Farah, extensive training over the years has led him to develop a body which is incredibly adept at pumping oxygenated blood to his working muscles without him tiring. Were you or I to attempt to cover the same distances as Farah, we would quickly tire, as our cardiovascular system could not keep up with the demand for oxygenated blood over such a long period.
The health benefits of cardio fitness
Naturally, improving cardiovascular fitness improves cardiovascular health, with reduced risk for heart attack and stroke, and better cardiovascular health readings in general. And the American Heart Association reports that active people with existing cardiovascular concerns are less likely to die prematurely of these conditions than inactive people.
What’s more, research published in the journal Circulation found that improved cardio fitness over a six-year study period correlated with a 19% decreased risk of heart disease and stroke in men – along with a 15% lower risk of death from any other cause.
Among the main reasons for this include healthier cholesterol levels and an improved health of the blood vessels that is a direct effect of being cardio fit. Regular cardio exercise has been shown to increase the level of high-density lipoprotein (often referred as “good cholesterol”) while lowering levels of low-density lipoprotein (that “bad cholesterol”).
And aside from the obvious benefits to the cardiovascular system, cardio fitness provides a further boon to many of the body’s other vital functions – with a stronger immune system one of the other key advantages to note. Not only does regular cardio activity help to flush bacteria from the lungs and airways; it also causes changes in the body’s antibodies and white blood cells – immune system cells that fight disease. As these cells begin to circulate faster, they are able to detect and potentially stave off illnesses much earlier.
There’s also plenty of evidence highlighting the ability of cardio fitness to lower the risk of developing diabetes, as well as to help manage the condition for those suffering from it. Regular cardio exercise increases the ability of our muscles to utilise glucose, thus helping to regulate blood sugar and reduce insulin spikes. In fact, just one session of moderate exercise can have an impact on this, and daily cardio activity (especially in line with a proper diet) is shown to play a considerable role in regulating glucose levels and insulin spikes over the longer term.
Finally, as regular cardio activity improves blood flow quality – not to mention releases endorphins – cardio fitness also tends to result in better mental health and improved mood. A collection of studies published in the Primary Care Companion to the Journal of Clinical Psychiatry found cardio exercise – such as jogging, swimming, walking, cycling, and dancing – reduces both anxiety and depression. The journal references a paper written by Polish professor Monika Guszkowska of Józef Piłsudski University of Physical Education in Warsaw, which cites increased blood circulation to the brain as the primary reason for these benefits.
Getting it right
Despite its many and varied health benefits, the fact is that most of us are just not up to scratch when it comes to cardio fitness. That’s not particularly surprising here in Dubai, where we spend hours at our desks during the week and hours at those infamous buffets on weekends. And of course we are not a walking culture here – not by a long shot.
But, if we are speaking honestly, those are just excuses. And with physical inactivity among the leading causes of most cardiovascular illnesses, it’s time to put those excuses aside and find the required discipline. Because the need to get active and improve our cardio fitness is clear – particularly if you are already showing signs of poor cardiovascular health. Should you, for example, find yourself out of breath after climbing stairs or running a very short distance, or if you suffer from aches and pains after even the mildest of exercise, that just won’t do.
To be clear, you do not need to hit the gym for hours on end: just 150 minutes of moderate exercise per week – that’s around 20 minutes per day – is all that is required according to the American Heart Association. And as I touched on above, combine that with a healthy diet, and you are doing the two most important things any human can – and must – do for health.
The opinions in the column are by Dr Graham Simpson, the Chief Medical Officer and Founder of Intelligent Health, a preventive medical centre located in Jumeirah, Dubai, and are not necessarily those held by Esquire or Hearst International.