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  • Writer's pictureGary Moller

Sudden Cardiac Death among Older Athletes

Updated: Jul 21, 2019

A practical guide about how to avoid suddenly dying while exercising

My father, Gordon, in his early 70's, died suddenly during his regular Sunday morning walk/run. He was about 20 meters into climbing a steep path when it happened. He was dead before he hit the ground. Looking back on it now, this was a good way for him to go, but it was untimely. He should have had at least another 20 years if only he had done some things differently.

Sudden cardiac death during exercise is rare and it is hard to identify common factors across all ages but there are some commonalities with older athletes that point to ways we can possibly reduce the risks a little, if not by a lot.

Although this article concentrates on older athletes, it is still relevant for the young ones.

(When I was studying sports medicine at the Otago School of Medicine, one of my major topics was "The Risks of Sudden Death During Exercise")


An example of intense, brutal exercise at high altitude
Gary competing in the 2017 world champs at high altitude and in 34 degrees C heat; an extreme test of cardiovascular health and capacity.


The following guidelines apply to all intense sports and exercise, but especially to those that have the tendency to start with a BANG! and sometimes stop that way as well.


What does medical research have to say about sudden cardiac death during exercise?

If you are into reading the technical stuff, please read this academic review, " Sudden Cardiac Death in Athletes" by Meagan M. Wasfy, M.D., Adolph M. Hutter, M.D., and Rory B. Weiner, M.D. :

Key Points that are taken from this review:

  1. Though exercise is, in general, health-promoting, it is associated with an increased risk of sudden cardiac death for a small number of individuals who harbor cardiac conditions.

  2. Sudden cardiac death is the most common medical cause of death in athletes, with an incidence of around 1 in 40,000 to 1 in 80,000 athletes per year according to the most recent estimates.

  3. The risk and causes of sudden cardiac death vary based upon the athlete population. Male gender, black race, and basketball participation all place an athlete at higher risk. Sudden cardiac death in younger athletes (< 35 years) is commonly due to inherited cardiac conditions, while in older athletes (> 35 years) it is most often due to atherosclerotic coronary artery disease.

  4. There remains significant debate over the best strategy to prevent sudden cardiac death in athletes and the role of the electrocardiogram in preparticipation screening. The optimal preparticipation evaluation for a given group of athletes depends on the risk of the population and available expert resources.

The authors also said: "There was no associated plaque rupture on angiography in any participants with CAD, suggesting that the SCA was due to supply/demand mismatch".


CAD = coronary artery disease. SCA = sudden cardiac arrest. SCD = sudden cardiac death

What we can take from this article are the following points:

  • SCD is rare and almost impossible to predict.

  • Preparticipation screening, other than for special groups, is of little benefit for the general population.

  • The most likely cause of SCD is insufficient blood supply to the heart to meet the dramatic increase in energy demands of the heart during intense exercise (a supply/demand mismatch). Hence the reason why the warm-up and starting a race advice I'm giving here is so very important for older athletes as a way of avoiding catastrophic supply/demand mismatch.


It is normal to prepare for these intense starts by doing a thorough warm-up but this is not always the case or possible. A paddler, cyclist or runner may thoroughly warm up only to end up waiting, stationary on the start line in the cold and wet, starting the race as good as without any warm-up.

As we get older a number of things happen deep within our bodies that increases the possibility of sudden death during exercise:

  • Plaque builds up inside our blood vessels. This is a like the scale that builds up in the water pipes of our houses. This is fatty and/or hard calcium. The rate that this builds up is influenced by the makeup of the blood, protective nutrients and the presence or absence of inflammation.

  • Tissues, especially the arteries, harden due to scarring and calcification. This process, along with laying down of plaque, is happening in at least 80% of people and begins early in life. Hard, scarred, partially blocked blood vessels, as well as muscles that more gristle than muscle due to chronic overwork and repeated injuries make it progressively harder to pump life-giving blood through the body.

  • Micro blood vessels become damaged and blocked. Tell-tale signs of this process, atherosclerosis and arteriosclerosis, may be seen as the development of tiny spider veins, which are most obvious around the insides of the ankles. When your optometrist looks at the back of your eyes, micro blood vessel die-off is being examined.

  • Systemic inflammation increases with age. The modern, globalised diet can be described as being "pro-inflammatory". Throw in toxins such as medications, arsenic, mercury, lead, herbicides, pesticides, illness and disease - infected gums for example - and excessive exercise - the inflammatory burden may be overwhelming.

  • Mineral and other nutrient imbalances and deficiencies get worse with age. Many minerals, principally calcium, magnesium, sodium, potassium and iron, and the fat and the water soluble vitamins, must all be plentiful and in balance for robust cardiovascular function.

  • Peak cardiovascular output declines by a factor of about 0.01 per year of life after the age of 28-30. This equates to about one heart beat less off your peak heart rate per year (this is where the 220 beats per minute - minus your age comes from to estimate your age-adjusted maximum heart rate). So, the typical 50 year-old athlete has around 20 or more fewer heartbeats to play with as compared to a 30 year old opponent. By 65 or 70 years of age the loss of peak cardiovascular capacity is huge and it shows in the performance.

  • The older athlete may be completely asymptomatic of any blood vessel blockages until the narrowing exceeds about 80% or more of a blood vessel's diameter. The only hint may be a faster than expected deterioration of physical work output and this is usually put down to "getting old".

As you read this you might have realised that all of the above are actually independent of and not the inevitable consequences of ageing. They are preventable, manageable and often reversible. Regardless of one's old age by the way.

The best measure of how well you are doing with this is your peak heart rate during exercise. If it is a little higher next year, despite you being a year older, then you are doing something right!

Reality check: The absence of symptoms does not necessarily mean the absence of disease. You may feel nothing at all but disease may be present, a bit like rust deep within your car chassis. All is well until you run over a pothole at speed one day and the wheels fall off. Bear in mind that medical tests for assessing cardiovascular risk during exercise may be no better than 30% effective in picking up anything that may be amiss.


Signs and symptoms of deteriorating cardiovascular health during exercise


For the sake of practicality, I'm restricting this section to what you, the athlete, can be assessing during exercise and rest, rather than including what may be measured in a medical or exercise physiology clinic.

These are most important for anyone who has a past history of cardiovascular disease, including atrial fibrillation, angina and heart attack. Bear in mind that first heart attacks are often silent and usually go undiagnosed, mistaken for a bout of indigestion or a chest muscle strain until the next and more catastrophic event hits.

Even if you have just been cleared by the cardiologist during your health-check which may have included an exercise stress test, please do not ignore any of the following:

  • Being unusually slow off the mark when the gun fires. Most older athletes know this one: the younger ones take off like crazy while the oldies gradually wind into the race, hoping later on to overtake those inexperienced youngsters who went out too fast. If you are much slower than usual in getting underway, take care!

  • Cramping in the lower legs and/or more frequent problems with calf strains. This may be more of an issue at the beginning of exercise and may diminish as one warms into it. The other symptom to be aware of is calf cramps that wake you during deep sleep.

  • Chest, arm, back and groin pain during exercise. This may come on as the pace quickens or when going up a hill and relieved by slowing down. The cause may be cardiovascular and not just mechanical.

  • Migraine-like head-ache during exercise. This may be muscular but may also be due to sky-rocketing blood pressure or an aneurysm.

  • Feeling spacey or even loss of consciousness during exercise. The cause may be low blood sugar but it could also be that the heart is failing and the blood supply to the brain is decreasing.

  • Irregular or racing pulse, or unusually slow pulse during exercise and/or while at rest.

Combine any of the above with a sense or feeling of distress and it is time to STOP! Lie down with your head and chest raised a little above your hips and prop the legs up a little as well. This position is the easiest on the heart by facilitating drainage of the legs and lungs. Get medical help. It is better to have some fuss made over you than to be dead. At the very least, slow right down, finish early, rest up and book in for a thorough medical examination.


Hints that circulation to the legs may be declining

  • Foot and ankle pain or outright injuries that appear to come on from nothing, are very slow to heal and may even fail to heal fully.

  • Discoloration of the skin overlying the shins, wounds that are slow to heal, varicose veins and spider veins. Your lower legs and feet are the points furthest away from your heart and lungs. If there is a significant loss of circulation, it will often first be seen in the feet. Easy injuring, poor healing, cramps and even deformed and fungal-infected toenails are indicators of deteriorating circulation to the legs.

  • Fungus toenails.

  • Leg cramps that are suffered during deep sleep.


Gary Moller Karapoti Classic race
Gary on his way to smashing the 60+ age-group record at Karapoti


Why do people suddenly die shortly into intense exercise?


Think of sports like mountain biking, cyclocross, canoe and ski racing and many running races: the gun goes and there may be a frantic dash to get the best position. In these races a slow start can mean being caught in a massive traffic pile-up shortly into it so everybody starts at a crazy pace!

Video below:

Have a look at the starts in the men's and women's races to get an idea of the intensity of the starts.

By the way, I'll be competing at the same Canadian venue this August to defend my age group title. It will be tough.