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In July 2010, Danish pro Rasmus Henning put the Ironman world on notice that he was a viable threat to win Kona. Craig Alexander pegged him as one of the most capable challengers. But just four months later, his long-distance career started to crumble—in part because of mysterious, muscle-shredding cramps. With the help of a Stanford nutritionist and an upside-down coaching strategy, Henning kicked off 2012 with an impressive victory at the 2012 Abu Dhabi International Triathlon. Now six months after that victory, Henning has decided he will retire as a professional triathlete after competing in October 13’s Ironman World Championship. In honor of Henning’s announcement, here’s a look back at a feature on the Danish athlete. This article originally appeared in the July/August 2012 issue of Inside Triathlon magazine.
When Rasmus Henning stormed across the 2010 Challenge Roth finish line in the incredible time of 7 hours and 52 minutes, his dominant victory seemed like another step in the Dane’s inevitable march to contending for an Ironman world title. Earlier in his career, Henning proved he has the engine of a thoroughbred by winning five ITU World Cup races and appearing in two Olympic Games. A victory in 95-degree temperatures at Ironman China confirmed his ability to tolerate heat. Winning under pressure is no problem; Henning twice bested incredible fields to win six-figure paychecks. This rare blend of abilities led three-time Ironman world champion Craig Alexander and just about every other triathlon pundit to identify Henning as a likely Kona winner. Then, just four months after winning in Roth, Henning’s progression abruptly stopped.
The 2011 Abu Dhabi International Triathlon, held in March, started like many long-distance races for Henning. He swam at the front of the group, but he felt a strange twitching in his leg during the swim. By the time he made it to T1, his right leg was seizing up. He had experienced cramps late in races, but this was different. His knee had locked and Henning needed to use his hands to manually bend the joint. It “felt like someone was hitting me with a baseball bat,” he recalled, but thought it had to be some strange temporary problem, so he forced himself onto the bike and tried to pedal away. His body simply wouldn’t cooperate. It was so painful Henning literally screamed in pain as he tried to force his leg through a pedal stroke. Just a kilometer into the race he pulled over, dropped his bike and attempted to physically force his leg to relax. The rogue muscle wouldn’t release. After the pros and age groups rode by as he stood on the side of the road, an ambulance eventually arrived and shuttled the Dane back to the start area. Even with massage, help from a physical therapist, and all the willpower Henning could muster, the thigh just wouldn’t relax. It was as if rigor mortis had set in. Two to three hours later the quad finally relaxed its death grip on Henning’s knee joint. The contraction was so strong that it left him sore in that one sliver of his quadriceps for nearly a week.
Henning returned home and tried to reason through the problem with his longtime coach, Michael Krüger. They concluded electrolyte depletion couldn’t have been the cause because the cramps started too early in the race. Exhaustion didn’t make sense either; Henning had successfully swum at that level for many years. They tried a few small changes, but their attempts didn’t work. The same thing happened all over again three months later at Challenge Aarhus, a half-iron-distance race in Denmark. The cramp was so severe Henning got an MRI after the race. It revealed “severe muscle damage” to his vastus lateralus, the portion of his quad closest to the IT band. With the Abu Dhabi and Aarhus debacles coming on the back of a second consecutive disappointment in Kona, Henning said he was racing “like a shadow [of myself],” and he still didn’t have a solution to his mysterious cramps.
Fast-forward to T2 at the 2012 Abu Dhabi International Triathlon. Henning rips out of transition with a look of frantic aggression, three strides ahead of the six other athletes who finished the bike with him. Instead of putting on socks as he usually does during long-course races, Henning ditches them to save a few seconds and “put pressure” on the other athletes. It’s a six-hour race, but Henning is racing like he’s back on the ITU circuit. The others can’t reach his coattails. He caught the racers that broke away on the bike and crossed the finish ahead of many of the world’s best long-distance triathletes. It was his first major long-course victory in nearly two years. Delirious with pride and relief, Henning said after the race, “I haven’t been able to put together a top-notch performance since Challenge Roth in 2010,” acknowledging his frustrating two-year battle with cramps. “I’ve always tried to tell myself that I know I can come back and perform really well, but it’s just so hard when every time I fall apart. This was really important to come back on top and show that I’m a really, really good athlete over the three disciplines.” The ability that caused Craig Alexander to identify Henning as one of his most potent challengers just two years ago was back. How was he able to channel his former self?
He got a new coach, for starters. In June 2011, Henning and Krüger, his coach of 12 years, mutually agreed to separate. Henning started with Matt Dixon of Purplepatch Fitness three weeks later after an extensive mutual interview process; solving the cramping mystery was their first priority. After failing with the usual barrage of potential nutrition-based fixes—stuff you can find in the pages of magazines such as this one—Dixon and Henning realized they needed help. They turned to Stacy Sims, Ph.D., of Stanford, a sports nutritionist Dixon has worked with for years who he believes to be “10 steps ahead of most if not all the other dietitians when it comes to fueling for endurance sports.” Together they came up with a two-pronged plan to attack Henning’s chronic cramps: Dixon adjusted Henning’s training, and Sims helped him implement her own nuanced nutritional philosophy.
Sims’ ideas go way beyond the building blocks of sports drinks. She examined his ingestion of the basic components of sports nutrition—carbs, water, electrolytes—but found one of the biggest breakthroughs in a typically overlooked aspect. He was ingesting a lot of sodium chloride—table salt, also used in some beverages—in the days leading up to a race. The sodium and the chloride molecules separate in the gut, and Sims says excess quantities of chloride can interfere with intestinal cells and cause “leaky gut syndrome,” the abdominal discomfort every triathlete has experienced. She switched him to drinks with sodium citrate, a different salt compound. Citrate is used in aerobic metabolism, so it quickly gets used. She also added magnesium and potassium to his pre-race diet to “top off his body stores of trace elements and minerals that he needed” before racing. Next, Sims diluted the carbohydrate concentration of the sports drink he took during races and increased his sodium intake to maximize his rate of fluid absorption while ignoring the quantity of calories he needs per hour. She believes “hydration is different from food,” so she instructed him to replace those lost calories by eating solid foods during the race such as a bar, salted potatoes, low-fat brownie or chews. Finally, they brought down the total calories he consumed during the race. “Those things so far have been the absolute solution,” Dixon said, to the nutritional component of Henning’s cramping problem.
While Sims addressed his diet, Dixon was busy flipping Henning’s training on its head. Many people typecast his coaching style as “quantity over quality,” but Dixon takes exception to that categorization. Instead, he would classify himself as a problem-solving coach, utilizing vastly different strategies to prepare his athletes based on their personal successes and failures. Despite using distinct methods for different people, he comes back to one foundational philosophy for every person: Keep the athlete fresh throughout the season rather than burdened with fatigue. According to Dixon, Henning was a classic case of an athlete who was overly fatigued throughout the season and on race day. Racing on tired legs, he surmises, contributed to the cramping problem.
Dixon believes that Henning, like many Ironman athletes, became “a little obsessed with accumulating miles. Long runs and big, long bike rides.” Fear-based training, as Dixon likes to call it. Henning was training for the distance rather than training to be fast. Despite the Dane’s newfound affinity for long workouts, he told Dixon that he “responds very quickly to intensity.” After failing with a more traditional training strategy leading into Ironman Hawaii in 2011, Dixon instituted a fundamental change in Henning’s preparation for Abu Dhabi in 2012. He upended the periodized Ironman build. Instead of starting with aerobic base miles, then adding race-specific intensity and distance workouts a few months out and resting in the final weeks, Henning’s longest aerobic miles came long before the race without any race intensity. He rested 3–4 weeks out instead of immediately leading into the race. Dixon then gave him “a taste of intensity” in the three weeks before the event while keeping his total training low enough to avoid “building a reservoir of fatigue.” Instead of resting before the race, he built into it and regained the edge that propelled him to Ironman dominance earlier in his career.
Henning’s confidence has at least partially returned since reaching its nadir at Ironman Hawaii in 2011, where he solemnly admitted over post-race beers, “You know I’m not happy with my race.” But he isn’t ready to proclaim himself a Kona contender just yet. “In 2009 I was very confident about Kona. I thought I had it all planned out. Then, after racing twice without any success I’m still a bit more respectful to the race and the guys that have done well,” he said, sounding a lot like Chris McCormack before his 2007 breakthrough on the Big Island. Whether Henning reaches that level still remains to be seen, but his performance at the Abu Dhabi International Triathlon proved the “old Rasmus” is back.
A Taste of Intensity
Dixon describes Henning’s key bike and run workouts leading into Abu Dhabi.
Rather than riding five hours steady state, I would instead have him go and ride four hours. After a warm-up, he does 60 minutes broken into three 20-minute segments: 20 minutes under Ironman intensity; 20 minutes at Ironman intensity; 20 minutes above Ironman intensity. For a guy at Rasmus’ level, that’s actually a pretty high effort. Then he’ll go 45 minutes, broken into three 15-minute segments with the same progression of effort.
On the treadmill I’ll have him do 2–3 rounds of 8×2 minutes at close to threshold effort up a grade with about 30 seconds’ rest so he’s up there more like at half-Ironman pace. Right after those, it’s straight into a flat 10-minute piece at Ironman pace followed by a 5-minute easy running break before doing it again. This session ends up being about 75 minutes, and it’s more strength- and intensity-focused than most long runs.