Yesterday Open Water Source hosted a fascinating web-presentation by Peter Attia, a physician and Catalina Channel solo swimmer. The topic: Nutrition for Open-Water Swimming. Right up my alley, to say the least! There’s good news and bad news.
Bad news first: The webinar was oversubscribed so, despite pre-registering a week ahead of time, I got locked out. The good news: I was able to obtain the audio and slides, and “listen in” after the fact. (Friendly suggestion to the good folks at Open Water Source: Please don’t overbook your webinars. I realize they’re free, but still…)
The even-better news: The webinar was excellent. Though, somewhat different than I expected. A few weeks ago a friend sent me a whitepaper authored by Dr. Attia, entitled “Swimming in the Intensive Care Unit.” The gist of the paper is that a marathon swim is enormously stressful on the body, producing physiological symptoms not unlike those of a patient in the ICU with a traumatic injury. Therefore, proper nutrition is critically important to the success of such an endeavor. His recommendations boiled down, interestingly, to almost exactly what I had discovered on my own:
- The purpose of feeding during a swim is to supplement your body’s other energy sources (glycogen and fat), not to replace every single calorie you burn.
- Liquid feeds are better than solid feeds, because solids are difficult to chew and digest while swimming.
- Feed often - every 15 or 20 minutes - to minimize blood sugar fluctuations.
- An 8-10% carbohydrate solution (equivalent to, at most, 270 calories per hour) is best.
- Maltodextrin is a better carb source than dextrose and/or fructose - its lower osmolality is less likely to produce gastric distress.
- Fluid intake should be enough to require urination at least every hour.
- Augment the carb drink with protein (or preferably, free-form amino acids) to mitigate muscle breakdown.
- Do not supplement electrolytes in a saltwater swim (at most, perhaps a small amount of potassium).
Indeed, Dr. Attia’s specific product recommendations corresponded exactly to the products that, independently, I had already found to work best: Maxim and Hammer Perpetuem. So - good for me.
What I didn’t realize until yesterday is that the “Swimming in the ICU” paper is actually outdated! Dr. Attia wrote it circa 2009, but in the past two years has completely changed his thinking and approach to nutrition.
How so? Stay tuned for Part 2…