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Lessons from Kona

By: Matt Erlenbusch, MS, RD
Private Practice Nutrition Consultant/Coach
October marked the 30th anniversary of the Ironman World Championship in Kailua-Kona, on Hawaii’s big island. This triathlon is considered one of the most spectacular endurance events on the planet, not only because of the world-class competition, but also the grueling distances involved (2.4-mile swim, 112-mile bike, 26.2-mile run) under Kona’s famously extreme hot, windy, and humid conditions.

The Hawaii Ironman is always an inspiration to those who follow it every year, but the relatively young race also teaches us how to master its challenges. From its humble beginnings in the late ‘70s and early ‘80s, when competitors were weighed for hydration on checkpoint scales, the sport and science behind it have continually evolved to very sophisticated levels. By moving their bodies 140.6 miles in opposition to the relentless forces of heat, wind, humidity, and exhaustion, what do trailblazing Kona triathletes have to teach us?

The Great Dane
One standout athlete who really pushes the edge in this tropical Petri dish is Denmark’s Torbjørn Sindballe. After several years at the elite level, he has truly broken through in Kona in 2007 and 2008. He’s stuck his neck out over the last two years in a bid to lessen the effects of Kona’s heat and humidity on him, and to seek an advantage against his fellow competitors. Last year, he finished third overall. This year, he was first off the bike by over 4 minutes, but faded during the run due to nutritional issues. Sindballe is a large athlete, by professional triathlete ectomorph standards. At nearly 6 feet, 3 inches high (190 cm) and 178 pounds (81 kg), his body surface area is less than most of his Ironman peers. This means Sindballe has a diminished ability, via sweat and blood flow to his skin, to dissipate the heat generated by his massive muscles as they power him to the sharp end of the race.

Sindballe’s unprecedented strategy to manage his unique heat challenges over the last two races in Kona has been to dress from head to toe in all white, essentially becoming a human heat reflector. White hat, white long-sleeved jersey, white thigh-length shorts, and white knee-high socks. Even white gloves! For 30 years, Ironman racers have worn as little as public decency standards have allowed, in an effort to beat the heat. Is Sindballe onto something we can learn from? Let’s find out what the sports scientists can tell us.

In 2007, the American College of Sports Medicine published two separate position stands that weigh in on these issues: External Heat Illness during Training and Competition and Exercise and Fluid Replacement. These peer-reviewed conclusions verify what those who have trained and competed in extreme elements intuitively know: The Hawaii Ironman is the perfect storm of athletic/environmental chaos. Specifically, the greatest risk of exertional heatstroke, heat exhaustion, and exercise-related muscle cramps occur during high-intensity exercise in hot/humid environments.

Some Don’t Like It Hot
As ambient heat increases above 68 degrees F (20 degrees C), exercise time to exhaustion decreases, perceived exertion increases, and energy stores diminish at a faster rate. As core body temperatures exceed 104 degrees F (40 degrees C), muscle fibers break down, blood flow to the skin rises (stealing blood away from working muscles), and sweat secretion skyrockets (stealing precious water from working cells). Sindballe actively attempts to minimize the effect of ambient heat with reflective clothing.

Nor Do They Like It Humid
The scientific literature establishes that increasing humidity seriously stymies our skin’s ability to cool our bodies. Moisture-saturated air offers a tiny gradient for heat-charged perspiration to escape the skin’s surface. Just like heat, this causes an increase in blood flow to the skin to force heat off via radiation and convection. This is blood flow that should be going to your working muscles, not urgently trying to keep your body cool. To manage this, Sindballe keeps his entire white fabric network wet with cool water, creating a steep gradient to suck the heat out of his core.


Water Works
Dehydration is another specter creeping around the island on race day. Dehydration raises the body’s core temperature, making the battle against the elements exponentially tougher. Most know that even minimal dehydration increases heart rate and perceived exertion. Dehydration exceeding 2% of body weight degrades endurance performance, lowers time to exhaustion, and impairs cognitive/mental performance. When fluid losses exceed 3% of body weight, sweat production and blood flow to the skin actually decrease to preserve the integrity of the vital organs.  This extreme scenario exacerbates a devastating and medically dangerous domino effect where the body requires outside assistance to rehydrate and cool down.  

Preventative Measures
In addition to following Sindballe’s lead by choosing reflective clothing and keeping it covered in cool water, you do have another option.  The ACSM tells us that the best protection against exertion-related heat problems is to acclimate to the hot and humid environment in which you will be competing: 10–14 days of exercise training in heat has been demonstrated to improve heat acclimatization. While this might not be practical unless you are a heavily sponsored professional athlete without significant domestic commitments, mimicking extreme conditions with extra clothing is an option many temperate climate athletes such as myself have had success with. A jacket and/or tights in the summer can help train your body for what’s to come in a place like Kona, and your body will begin making physiological adaptations in kind. Sure, your long clothing may make you stand out from your training gang, but like Sindballe, you may be rewarded for daring to be different. This approach could prove to be the next best thing to getting a condo for an extra week or two before your race.  If you do train in the summer with long-sleeves on, keep the heat stress sensibly small to avoid overheating.

Lesson Taken
Torbjørn Sindballe is doing everything in his power to successfully take on Hawaii’s elements. He’s inventing clever ways to shave seconds off his performance times. At his level, those tiny increments in an 8+ hour race often mean the difference between standing on the podium or not. Few of us can relate to that level of performance, but we can all relate to pushing ourselves to our absolute limits. His attempt to keep his body cool is a smart strategy and his breakthrough performances suggest that we can all learn from this pioneer.


References
Armstrong et al, American College of Sports Medicine Position Stand, Exertional heat Illness during Training and Competition, 2007, Medicine & Science in Sports & Exercise
Sawka et al, American College of Sports Medicine Position Stand, Exercise and Fluid Replacement, 2007, Medicine & Science in Sports & Exercise
Topics: General, Post-Workout, Recovery, Research

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