Finish Line Collapse

If you missed this at last year’s Mens WTS grand final finish – Jonny Brownlee lost consciousness within 500m of the finish line. His pace slowed, and he wobbled before his older brother Alistair helped him across the finish line. You may have also seen a video of two women crawling across the finish line in Kona in 1997. So why do triathlete’s collapse at the finish line?

Heat Exhaustion

Most commonly, athlete’s collapsing can be attributed to heat exhaustion. Heat exhaustion is when the body’s core body temperature exceeds what is deemed normal or in the tolerance zone for healthy functioning. When core body temperature exceeds this tolerance level it results in:

Reduced performance as the brain goes into self-preservation mode and recruits less muscle fibres
Feeling of nausea and inability to tolerate nutrition
Possible liver, kidney or brain damage, heart failure or death

Heat exhaustion is most prominent during the run leg as the water in the swim and air flow on the bike assist the cooling process – thus reducing core body temperature. It is also exacerbated by increased body weight and dehydration.

Central Governor Theory

As your core body temperature increases, the brain receives the distress signals from the muscles and other organs in the body. Usually, upon receiving these signals you would slow down to avoid further damage. However, some elite athletes can manage or ignore these messages and continue on despite potentially causing further damage. This theory is called the Central Governor Theory. “The brain will override your physical ability to run and ‘shut the body down’ before you’re able to do serious or permanent damage to yourself.”