As I sat on the plane for 15+ hours today, with a mental block on a new blog post, I came up with this beauty as it relates to IM preparation……more specifically, the carb load!
For many, this is the most fun, anticipated, and exciting thing about IM prep. For others, its a dreadful experience of forcing food with a bloated gut. Let’s first review what the purpose of any carb load is: to make sure you arrive at the starting line with fully stocked muscle glycogen. Now, I can do this quite simply be eating a ton of carbs starting 1 week from race day. Why isn’t this a good approach? Because, any potential benefit you get from the carb load (which is small in the first place), is negated by the fact that you put on 3 pounds through the process (worth about 6 minutes on race day). So, its intuitively clear that any carbohydrate loading program should try to ride the line between these two competing interests. How heavily you weigh either one is based on how critical one is versus the other for your race distance. That is, longer races require a longer carb load since the impact of having fully stocked muscle glycogen can be more significant for those races versus shorter ones. This is important, even if it means putting on a half pound (worth about 1 minute in IM which shows how small an impact we are talking about with this whole discussion).
With those interests in mind, I like to start the carb load for IM at lunch time 2 days out, and shorter than that as the race distance gets shorter and the potential positive impact becomes smaller. Sprints require no carb load while Olympic and longer do. How significant the load is (how long it is) depends on the length of the event.
Another, potentially skeptical addition to the proven carb load, is a 1-2 day fat load prior to the carb load for the real long events like IM. An example may look like this:
Monday: Fat Load
Tuesday: Fat Load
Friday: Start carb load at lunch (half carb load day)
Saturday: Carb Load
Fat load definition – have your body weight (in pounds) in grams of fat that day…..very little focus on eating carbs and protein. These days should result in 0-200 calorie surplus overall which defines the amount of carbs and protein we are talking about. Fat choices should be as omega 3 and omega 6 rich as possible while avoiding saturated fats.
Carb load definition – 4.5 times your body weight (in pounds) in grams of carbs that day…..very little focus on eating fat and protein that day. These days should result in a 500-1000 calorie surplus overall. Carb choices should be very low in fiber and nutrition density. Almost no fruits and vegetables (this is about the only time you will ever hear me say that).
I’ve found the fat load to work quite well (based on real world experience) with it’s length also varied by the length of the event. As I mentioned, this one is a bit skeptical (try to look up some of the research), but for the sake of full disclosure, it is something I have been experimenting with for a while with athletes depending on ability and body composition goals.
Happy eating on race week!