In light of the recent death of a high profile endurance athlete high intensity exercise has again come into the spotlight. The question on a lot of people’s minds is  How is it possible for a seemingly fit healthy individual with no known risk factors to die suddenly from a heart attack? If I put on my exercise science hat there are a couple of possible explanations. Maybe in some people high intensity exercise triggers an underlying heart issue or maybe it’s the cumulative effect of long term high intensity exercise, that causes structural and functional changes to the heart ultimately resulting in heart defects. Unfortunately, it’s pure speculation but this case definitely highlights the need for further research into this issue. Who knows? It may well be in the future that people planning to take up high intensity activity/sport may be encouraged to undergo a pre-screening exercise stress test to identify possible risks.

For a period of a approximately ten years of  my career I worked as an exercise physiologist, conducting exercise stress tests on people from all walks of life, both athletes and non athletes. I can recall over the years a few instances of people with no known risk factors presenting with abnormal heart rhythms on their exercise tests. In such an event the doctor and I would stop the test immediately and refer the client on for further testing. I particularly remember one case when we were testing a client who was a keen squash player. He was 40 years old and played squash socially twice a week. He had no known history of heart disease and no obvious risk factors. During his stress test his ECG (Electrocardiogram) displayed evidence of abnormal heart rhythms. We immediately stopped the test and recommended he see a cardiologist for further testing. At the time he was annoyed that he couldn’t complete the test and even more annoyed that we recommended he cease all high intensity exercise including squash until if and when he was cleared by the cardiologist. About three months later I received a letter from this client that expressed his apologies for being so annoyed at the time of his consultation and his heart felt thanks for identifying the need for him to undertake further testing. The testing revealed an underlying heart defect, and it was recommended that he no longer engage in high intensity exercise due to an increased risk of heart attack.

So what’s the take home message from all this, given that there isn’t yet sufficient research to support the theories I mentioned above? I definitely see value in people undertaking high intensity exercise sport having a pre-screening exercise stress tests. If nothing else, you can find out how fit you are and even identify what fuel source your body is using for energy at different exercise intensities. If you’ve never exercised I’d highly recommend having a check up with your GP to get the thumbs up to exercise. Also make sure you know your family history so you can be aware of any underlying risk factors and most importantly listen to your body. Don’t dismiss any warning signals your body may be giving you. Pain is your body’s way of telling you something isn’t right.

Above all, stay well and keep exercising. Your body will love you for it!