New Study Links Dehydration to Muscle Cramps in IRONMAN Triathletes

A Washington State University-led study finds dehydration is strongly linked to muscle cramps in IRONMAN triathletes, contradicting previous beliefs about electrolyte imbalances. The findings could reshape athlete preparation and safety protocols in ultra-endurance sports.

As athletes gear up for the IRONMAN World Championship on Oct. 26, a new study suggests they may need to focus more on staying hydrated to prevent muscle cramps, a common issue in these grueling competitions.

The research, led by Washington State University and published in the Clinical Journal of Sport Medicine, analyzed medical data from over 10,500 triathletes over three decades.

The findings reveal a strong link between dehydration and muscle cramps during the IRONMAN event, challenging the prevalent belief that electrolyte imbalances are the primary cause.

“We pretty much know that electrolyte imbalance is likely not related. Muscle cramps are complex but may be due to altered neuromuscular function issues, and now we think that more severe dehydration might be playing into that for ultra-endurance triathletes,” corresponding author Chris Connolly, an associate professor of kinesiology at WSU, said in a news release. “It’s important to point out that athletes are sometimes a little dehydrated before the race and some of them are very, very dehydrated by the end of it.”

The study also noted that exhaustion, low blood pressure, abdominal pains and headaches are linked to muscle cramps. Crucially, a previous experience of cramps during the race was the strongest predictor of future cramps.

According to earlier research based on self-reports, up to 63% of triathletes experience muscle cramps.

This study, however, focused on those who sought medical treatment, which often involves the administration of intravenous fluids. These cases represented about 6% of competitors over the 30 years studied.

Interestingly, the data show that athletes treated for muscle cramps had slightly better overall finish times compared to those who didn’t cramp.

“It probably has to do with the intensity of the activity, so people that are finishing faster, relatively speaking, are probably working at a faster rate and higher intensity,” Connolly added.

He noted that this connection would require further investigation.

Encouragingly, the incidence of muscle cramps at the IRONMAN championships has been decreasing by approximately 0.4% annually, indicating improvements in prevention and treatment protocols.

Connolly and his collaborator Douglas Hiller, a WSU clinical medical professor and IRONMAN Hall of Fame inductee, manage World Triathlon and IRONMAN data housed at WSU.

They aim to enhance the safety of these races through ongoing research. Both will be present at the upcoming championships in Hawaii, with Hiller assisting patients in medical tents and Connolly collecting data.

This year marks the second time the competition splits into separate events for male and female athletes, reflecting the sport’s growing popularity. While the women’s race recently took place in Nice, France, this rise in participation also brings heightened risks. Other serious medical issues in ultra-endurance triathlons include heat injury, severe nausea and hyponatremia.

“Ultra-endurance triathlons have had a meteoric rise in popularity across the world. It’s gotten huge. Anytime something that is this physiologically demanding grows that quickly, I think it takes a while for safety procedures and plans to catch up,” Connolly added.

This groundbreaking research could lead to new insights and strategies to better prepare athletes and improve safety protocols in the fast-growing world of ultra-endurance sports.