Extreme Endurance Exercise – what’s the real concerning stress here?

Extreme Endurance Exercise – what’s the real concerning stress here?

Extreme Adaption of Human Beings

One of the amazing capacities of human beings is their ability to adapt to their surroundings and extreme stress placed upon them.  The human being can transform itself to improve its chances of survival against extreme stressors, like starvation, heat, cold, and sleep deprivation.  Through real-time sending and analysis of nervous, hormonal, chemical, psychological, and conscious information inputs – the human body dynamically shifts and learns to accommodate new stressors placed upon it.

To the uninitiated, extreme endurance sport like ultrarunning, ironman triathlons, may be thought to bring havoc to the knees, the hips, the immune system, of those living such a lifestyle. Well, without the right training there are risks … but are the seemingly obvious risks (muscle/joint pains etc.) the real concerns to worry about?

Let’s take a look at three separate stressors, bought about from the direct training, and the typical lifestyle of extreme endurance athletes.

1) Rapid Intensity Change – Musculoskeletal Stress

In my Naturopathic studies, we were frequently reminded of the body is an integrated set of systems, not one system, and not a set of isolated systems. This is important, to help understand how endurance exercise trains the different body systems, at varied rates and speeds.  Most endurance athletes would know, that cardio-respiratory fitness returns faster, than does musculoskeletal strength.  The same stress (aerobic exercise) can trigger quite rapid changes to the efficiency of how blood-oxygen is delivered to cells, how lactic acid is handled and how carb-fats are oxidized.  Yet over the same period of time, under the same stress, in the same person, the adaptions of joint and soft-tissue strength typically take longer.  It’s here that many repetitive soft-tissues injuries are born – where the body crosses the line between progressive adaption and injury.  Saying that, seasonal athletes can learn this fast, and in a few seasons understand how to build pre-season, and course-correct musculoskeletal issues as they arise within the season.

2) Lifelong Endurance Exercise – Cardiovascular Risks

At the turn of the century, studies were emerging that suggested that life-long endurance exercise (repeated extended stress) raised the risk of atrial fibrillation (AF).  Recently, in an article titled “State of the Art Review: Atrial Fibrillation in Athletes”, researchers point out that the type, intensity, and amount of the physical activity being conducted, as key drivers to influencing the risk of developing AF. 

In a meta-study in 2018 researchers, analyzed almost 30,000 AF cases, a reported a ‘J-shaped’ curve of risk, where physical activity up to 20hours per week resulted in a lower risk of AF, whereas, physical activity over 20hours per week increased AF risk.  How much endurance exercise is conducted over one’s lifetime is a risk factor, and furthermore, males seem to carry higher risk.  Over time the study highlights, various remodeling of the heart, plus inflammation and changes to vagal-nervous tone.

3) Endurance athletes – Prediabetes Risk

Prediabetes and Type 2 Diabetes (T2D) continues to grow in prevalence with now 86 million  Americans believed to have prediabetes, based on a CDC report.  90% of prediabetics don’t know they have it, and up to 30% of them will develop type 2 diabetics within 5 years – if no weight loss or moderate physical activities are adopted.

However, while exercise improves fat oxidation and insulin sensitivity (lowering T2D risk), research is showing that in 15-20% of people, glucose tolerance and insulin sensitivity does NOT change following exercise training intervention.

 In a more recent study, researchers again found a wide variance, in exercise intervention improving insulin sensitivity, and calling out a significant proportion of people being ‘non-responders’ to exercise.

This is a red-flag for endurance athletes, with a false sense of security, blinding the athlete into believing they are immune to the diabetic risk.  This concern, in our view, is heightened when the common over-consumption of simple carbs by endurance athletes.  In our reportwe think a significant number of endurance athletes could be spiking their blood-sugars several times daily, and its not inconceivable that athletes could be consuming the equivalent of over 100 teaspoons of simple-sugars per week.

Then to make this risky metabolic stress even worse, two irresponsible studies have been published just this year, focused on training the gut to accommodate eve higher sugar loads for endurance sport training-racing.  Physiology and consumption methods are explored in a forced attempt to help the body ignore the clearly natural repulsive reaction of the gut to high dose simple sugar/carbs. Gut symptoms and reactions in endurance sport, is still the number 1 reason for not finishing an endurance race – our report on this is here.  But again, this is not simply about transient sugar gut symptoms stopping an athlete completing their race (hospitalizations are not uncommon, by the way).  There is something far more sinister at work here.   This is about potentially heightening the risk and predisposition to become a victim to the largest epidemic of the 21st century – diabetes.  A condition where high sugar in the blood increases the risk of blindness, kidney failure, heart disease, stroke and loss of limbs.

Endurance athletes only have to pick-up their preferred magazine, search google or facebook groups to find the increasing frequency of published articles, or athlete groups talking through a lower-carb higher fat-based approach to fueling, in training, racing and their diet lifestyle.

A Final Word…

There are some aspects of endurance exercise – that we put up with, like training load, and over-use injuries. We train, we get the balance wrong and we course-correct….for most of us – this is not a problem.

Then there is this emerging data suggesting life-long endurance sport, of over 20hours per week heightening the risk of conditions like atrial fibrillation – and clearly, we need more data and research done on why this is, and what to do about it.

Finally, we have a sea of data on the risks of high sugar consumption, type 2 diabetes, and chronic disease risk.  And furthermore, new emerging research that shows us, that exercise alone may not make all of us immune to the metabolic stress of prediabetes and diabetes proper. Be smart by reducing your sugar, carb intake to reduce your risks of running heightened blood sugar levels. Get started here – with our QuickStart Guide.

Go Longer. Team SFuels.

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