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ePublication of Australian Fitness Network

The extensive health benefits of regular physical activity are well known, and the layman may be forgiven for assuming that any exercise done in excess of daily minimum recommendations will further benefit health. Not so, say researchers from Monash University in Melbourne, who have warned that exercising at extreme levels could potentially lead to blood poisoning.

Also referred to as septicaemia or sepsis, blood poisoning is the result of a chemical leak into the bloodstream, causing an overactive inflammatory response. This can produce blood clots and impair blood flow which prevents the body’s organs from obtaining the oxygen and nutrients they need. While infants and children, the elderly and people suffering from chronic illness are at the highest risk of developing sepsis, extreme exercise may also be a significant risk factor for the condition.

But what exactly constitutes extreme exercise? According to Dr Ricardo Costa of the Department of Nutrition and Dietetics at Monash University, ‘exercising for more than four hours in one session is deemed extreme, as is engaging in repetitive days of endurance exercising.’ Costa notes that this form of physical activity is more common than many may realise: as the popularity of ultra-marathons and triathlons grows, so do extreme exercise practices.

In a study led by Costa, blood samples taken from individuals who participated in a 24-hour ultra-marathon were tested. The majority of samples displayed markers identical to those found in samples from patients who had been admitted to hospital for sepsis. Costa explains that exercise over a prolonged period of time causes the gut wall to change, allowing gut bacteria to leak into the bloodstream and triggering an inflammatory response from the body.

Highlighting the importance of following guidelines when it comes to participating in extreme endurance events, Costa said it is imperative that anyone undertaking an intensive endurance event undergoes a health check and builds upon a slow and steady training program, rather than jumping straight into a marathon.

Source: International Journal of Sports Medicine and Exercise Immunology Reviews

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