TRAINING INSIGHTS
Confronting Your Fears:
Cardio Pt.1
As of 1969 a prominent American physician, Dr. Harry Johnson, sounded the alarm bell to the public on the potentially lethal fad of jogging. To be fair, this warning was directed towards unfit individuals who had taken up the new pastime, but concerns around the potential dangers of vigorous exercise persisted for many years.
From Fear to Fitness Culture
This perception changed substantially over the 70s and 80s, however. Once people realized there was money to be made from aerobics classes and workout clothing, the public embraced leg warmers, lycra, and headbands with enthusiasm.
In the decades since then, resistance training has also risen in popularity. Aside from the sick pumps from a good chest and arm workout, resistance training has many functional benefits. It helps to increase and preserve bone density and muscle mass, protecting against osteopenia and sarcopenia as we age. Aside from a more robust body, resistance training helps to improve and maintain muscle power and balance.
The Rise of the “Cardio Kills Gains” Mindset
These well documented benefits—but mainly the sick pumps—have led many individuals to embrace resistance training, specifically bodybuilding, as their preferred training focus. Some individuals have even gone so far as to say that high-rep resistance training is all the cardio you need, and in any case “cardio kills gainz”.
If you are reading this newsletter, odds are you already prefer a chest day to a 10-mile run. While this is completely understandable (and correct), eliminating cardio completely may not be the best decision. In the following series of newsletters we will touch on the benefits of cardio for Health, Performance, and Weight Loss. There will obviously be some crossover between each of these topics, but let’s dive into the health benefits for today.
Why VO2 Max Matters
One of the most consistently reported benefits of cardiovascular training is an increase in VO2 Max. Bio-hackers and longevity influencers love obsessing over physiological markers when it comes to ‘optimizing’ their health, and will experiment with various supplement protocols to micro-manage these values—a topic we will have to return to on another day… However, if there was one value you really should try to worry about to increase your lifespan, VO2 Max would be it.
VO2 Max refers to the total volume of oxygen your body can consume during intense exercise, and is measured in milliliters per kilogram per minute (mL/kg/min).
What Cardio Actually Changes in the Body
There are various ways through which cardio training helps to improve VO2 Max. As the name implies, cardio serves to improve the contractile force of cardiac tissue, enabling it to pump more blood through the body per heartbeat. Outside of certain medical conditions, a lower resting heart rate is a decent indicator of cardiovascular fitness.
There are a number of other adaptations from cardio which are components of VO2 Max, which is why it is such a useful metric. Without going into an exhaustive list, the following are some examples. Cardio leads to greater red blood cell production, and an improved oxygen carrying capacity of the cells, allowing more oxygen to be delivered to tissues.
Within cells we have the famous mitochondria, or the “powerhouse of the cell”. Cardio helps to increase mitochondrial density and function, leading to more efficient production of energy from fats and carbohydrates.
Cardio, Longevity, and Disease Prevention
These adaptations have clear benefits in terms of improving quality of life, but they have also been shown to help increase lifespan. In cohorts of individuals whose health was tracked for several decades, higher cardio-respiratory fitness is associated with longer lifespan (Clausen et al., 2018), as well as reduced rates of various cancers (Ekblom-Bak et al., 2023).
These findings match up with findings from shorter term studies showing an inverse relationship between cardiovascular fitness and various biomarkers associated with inflammation and disease progression, such as C-Reactive Protein (CRP) and Interleukin-6 (IL-6).
The Most Underrated Tool for Long-Term Health
While bio-hackers will have a harder time selling regular aerobic exercise compared to an expensive and poorly regulated proprietary supplement, there can be little doubt that improving VO2 Max is one of the most powerful levers you can pull to improve health and longevity.
Although achieving the lofty heights of elite endurance athletes requires far more work than the busy professionals we coach can countenance, the good news is that a relatively modest volume of aerobic activity can lead to substantial improvements.
Does Cardio Really Kill Gains?
Of course, many of you reading have heard that cardio “kills gains”. Some may even consider sacrificing a few years on the back-end of life to maximize their current chest measurement. However, developing a good aerobic base doesn’t have to mean sacrificing sick pumps, and may even lead to sicker pumps in the future.
Next time we will take a closer look at how to improve cardio while laying down muscle.
References
Clausen JSR, Marott JL, Holtermann A, Gyntelberg F, Jensen MT. (2018) Midlife Cardiorespiratory Fitness and the Long-Term Risk of Mortality: 46 Years of Follow-Up. J Am Coll Cardiol. 2018 Aug 28;72(9):987-995. doi: 10.1016/j.jacc.2018.06.045. PMID: 30139444.
Ekblom-Bak E, Bojsen-Møller E, Wallin P, et al. (2023) Association Between Cardiorespiratory Fitness and Cancer Incidence and Cancer-Specific Mortality of Colon, Lung, and Prostate Cancer Among Swedish Men. JAMA Netw Open. 6(6):e2321102. doi:10.1001/jamanetworkopen.2023.21102.
Kullo IJ, Khaleghi M, Hensrud DD. Markers of inflammation are inversely associated with VO2 max in asymptomatic men. J Appl Physiol (1985). 2007 Apr;102(4):1374-9. doi: 10.1152/japplphysiol.01028.2006. Epub 2006 Dec 14. PMID: 17170204.
Strasser B, Burtscher M. Survival of the fittest: VO2max, a key predictor of longevity? Front Biosci (Landmark Ed). 2018 Mar 1;23(8):1505-1516. doi: 10.2741/4657. PMID: 29293447.