In a shift from earlier studies, a comprehensive analysis spanning three decades of IRONMAN competitions has established a link between dehydration and muscle cramps caused by exercise. This research, spearheaded by Washington State University and based on medical records from over 10,500 triathletes, highlighted a significant association between dehydration and the need for participants to receive treatment for muscle cramps during races. While common beliefs suggest that cramps are primarily caused by imbalances of electrolytes or potassium and salt, this study did not find supporting evidence, aligning with findings from other recent investigations.
As athletes gear up to tackle the waters of Hawaii for the first segment of the IRONMAN World Championship on October 26, it might be wise for them to focus on their hydration levels.
A recent study led by Washington State University, which reviewed three decades of top IRONMAN events, discovered a relationship between dehydration and muscle cramps triggered by exercise.
This research, published in the Clinical Journal of Sport Medicine, utilized medical information from over 10,500 triathletes and indicated a robust correlation between dehydration and the number of competitors seeking treatment for cramps during the event. While it is widely assumed that imbalances in electrolytes, potassium, and salt levels are the culprits behind cramps, this study found no support for that theory, which is consistent with other recent findings.
“It appears that electrolyte imbalance is likely not a factor. Muscle cramps are complex and might stem from issues related to altered neuromuscular functions; our findings suggest that more severe dehydration could be a contributing factor for ultra-endurance triathletes,” explained Chris Connolly, a physiologist from WSU and the lead author of the study. “It’s crucial to recognize that some athletes start the race mildly dehydrated, while others can become extremely dehydrated by the finish.”
Additionally, muscle cramps were found to be associated with exhaustion, low blood pressure, stomach cramps, and headaches. Notably, experiencing a muscle cramp early in the race was the strongest indicator of needing treatment later on; many participants dealt with multiple instances of cramping across the various stages of swimming, cycling, and running that make up the all-day competition.
Painful muscle cramps are among the most frequently reported issues in triathlons, affecting about 63% of athletes, according to past studies that relied on self-reported data. However, this investigation specifically examined those who sought medical aid for cramps, which constituted about 6% of competitors over the thirty-year span examined.
Interestingly, athletes who received treatment for cramps generally had slightly better finish times compared to those who did not.
“This may relate to the intensity of their performance; faster finishers tend to be those exerting themselves at a higher intensity,” said Connolly.
While this higher intensity might explain the increased occurrence of muscle cramps, further research is necessary to explore that connection.
On average, the rate of muscle cramps has decreased by roughly 0.4% annually at the IRONMAN championships, which researchers interpret as a sign of improved prevention and treatment methods at these events.
As the official custodians of World Triathlon and IRONMAN data at WSU, Connolly and his colleague Dr. Douglas Hiller—who is a clinical medical professor at WSU and a member of the IRONMAN Hall of Fame—are dedicated to enhancing the safety and overall standards of the sport through ongoing research.
They will be present at the medical tents during this year’s Hawaii race, with Hiller directly assisting patients and Connolly gathering data.
This year marks the second time that the competition has been divided into separate men’s and women’s events, with the women’s portion taking place in Nice, France last September. This division reflects the increasing number of triathletes participating in the sport.
However, Connolly warned that with rising participation comes heightened risks. Participants in extreme endurance triathlons may face additional health challenges, such as heat-related illnesses, severe nausea, and hyponatremia, which is a serious condition resulting from significantly low sodium levels in the body. Although rare, fatal incidents have also occurred during these demanding competitions.
“The popularity of ultra-endurance triathlons has surged tremendously worldwide. As participation grows, it often takes time for safety protocols and plans to adapt,” he stated.
Co-authors of the study alongside Connolly and Hiller include first author Paal Nilssen, second author Dr. Kasey Johnson both recent graduates of WSU’s Elson S. Floyd College of Medicine, and Dr. Thomas Miller from Virginia Tech.
