Fueling during the marathon is something I really want to figure out for future races. In training I rarely take anything before or during workouts. At most I will take in some caffeine and electrolytes. I rarely ever hit a wall or slow down in training. The interesting part is that if I do eat a meal (even 3-4 hours) before a long workout I almost always end up slowing or having to put in more effort over the last 3rd of the workout. I would not call it “bonking”, but there is a noticeable slow down and increase in effort….this does not happen if I do the workout fasted from the night before. Heck, I’ve had some of my greatest workouts ever (and yes, they are long…over 22-24 miles) with only taking in electrolytes (S-Caps).
After doing a ton of research on the topic I am wondering if I might have a little bit of reactive hypoglycemia. It is my experience in the marathon that really leads me to the reactive hypoglycemia diagnosis. Once I start taking gels or drinking Gatorade I notice the spike in blood sugar as I get lightheaded and even dizzy sometimes. If I don’t maintain the fuel (sugar) intake every 10-20 minutes I crash too much and end up slowing or putting in much more effort to maintain my current pace. Another interesting thing I have noticed over the past few marathons is that once I do start taking in fuel during the race I find myself slowing. For example, I may go from running 5:20s to feeling like it takes the same effort to run 5:35-40/mile. This has happened in every marathon I have done. I have not actually “hit the wall” or “bonked” since my first marathon, but I do end up slowing down significantly over the last 3rd of the race. I do not think it is a coincidence that the time of slowing down coincides with the 5-15 minutes after I start taking in fuel. I have experimented and started taking fuel at 3 miles, 6 miles, and even half way. Every single time the pace/effort goes within 5-15 minutes of taking in the sugar.
What am I going to do about this? First, I am going to try a diet higher in fats and lower in carbohydrates. I’m not talking about taking out carbohydrates completely, but I will definitely limit the amount I am taking in on a daily basis. The biggest things I am going to work on taking out are sugar and refined/processed carbohydrates. It is not going to be easy as I have a sweet tooth. Also, when I mention higher percentage of fats I am talking about more “good fats” (coconut oil, olive oil, fish, chicken, nuts, almond/cashew butter, avocados, etc…). My diet is going to consist of good fats/proteins, lots of vegetables and a limited amount of fruits (berries and apples as they are lower in fructose). Before you jump and say it’s not possible or unhealthy I urge you to do some research. I have been doing quite a bit of research on the topic and there is a ton of legit information out there. I’ve also been reading a bunch of information written by Professor Tim Noakes on the subject. I even had the honor of tweeting back and forth with him about the topic.
In the future I am not going to eat anything before a race of half marathon or shorter (I actually had my best half marathon ever last Spring without eating a thing beforehand….but I did start taking a sip of gatorade every 2 miles starting at 6 miles). For the marathon I am probably going to wait until much later in the race to fuel (if I fuel at all). I will still take in water/electrolytes.
I will try and keep updating my progress both with training and diet.
I would love to hear what other people have to say about this……