Title: Race Day Fueling
Author: Pamela Nisevich Bede, MS, RD, CSSD, LD
Nail down your fueling strategy now to stay fueled and break through walls on race day.
As race day looms near, it’s time to finalize your fueling strategy. Don’t get nervous if you have yet to think about fuel- you’ve still got time to tweak your hydration, energy, and electrolytes over the remaining MIT runs. And if you’ve not yet finalized your fuel plan, you’re probably not alone. Many first time marathoners, and even seasoned marathoners, struggle with nailing down what to eat in order to make it through long training runs and races.
Determining your best strategy can take some trial and error. You may need to try out different forms of fuel- gels, blocks, beans, chews, bars, and even real food- before you find your fit. Sometimes it takes trying out many different brands, flavors, and amounts before you hone in on your perfect fueling plan (so it’s best to start experimentation early) and once you find something that works for you, stick with it. It can be easy to forget what, exactly, worked for you out on the road so remember to write down your fueling regimen in your training journal. That way, the next time a long run is scheduled, there will be no question of what did- or didn’t- work for you.
Remember that in addition to fueling on the road, what you eat before the run is crucial. Your meals in the hours before the run – which should be high in carb, moderate in protein, low in fat and fiber - will supply your muscles with glycogen and will essentially top off your fuel tank. During the run, experts recommend you consume between 30-60grams of carbohydrate an hour. Personally, I aim for 30grams of carb each hour because I’ve found that this intake leaves me energized but is not so much fuel that my sensitive GI system erupts. Consume well below this target and you’re likely to run on empty, hit the wall and bonk. Once you hit the wall, it’s difficult- both physically and mentally- to recover so if your current fueling regimen leaves you dragging, consider adding in more fuel (chase with adequate fluids) and more often to your runs. You’ll want to start fueling and hydrating early and often because your gut can only absorb a small amount of carb at a time- and at a certain range of dilution- and too much at one time can send you searching for a porta potty. Below is a sample plan that may work for you. If you’ve never fueled during the run, this plan probably looks like it has way to much fuel. Don’t worry because you can train your gut to work up to this level of intake over the next few weeks (and for future races).
If you’re new to the fueling game, consider consuming half of the fuel during this weekend’s long run and then steadily increase until you get to a point where you are consuming enough fuel that you feel energized throughout the run but not so much that you have GI distress or feel bogged down. Remember, long run and race day fueling takes a bit of trial and error. With experimentation, attention to detail, and good record keeping, you can hammer out a plan that works for you. Best of luck in your training and fueling!
Sample plan resulting in an intake of 40-50 grams of carb (depending on brand of fuel) each hour of a 4 hour marathon:
Most gels provide approximately 25grams of carb. Gels should always be chased with water (check the back of the package to determine how much). While you might get sticky, it’s ok to consume part of a gel at one time and the rest a few minutes or miles later.
Most chews provide between 4-8 grams of carb per chew and should also be chased with water. Check the nutrition facts panel to determine how many carbs your brand provides. For the example below, I assumed that each chew provides 8 grams of carb
Most sports drinks provide approximately 15 grams of carb per 8 ounces of fluid. Don’t chase your high-octane fuel (gels or chews or bars, etc) with sports drink. Instead, alternate water and sports drink, always drinking to meet your thirst. The below plan lists carbohydrate-containing fuel only because it’s difficult to generalize a plan to meet every runner’s water and electrolyte needs. You’ll want to add in water according to the conditions and to meet your body’s needs.
20 minutes – 2 energy chews + water
40 minutes – 1 energy gel + water
1 hour – 4 ounces sports drink (hourly total: 48 grams of carb)
80 minutes – 2 energy chews + water
100 minutes – 1 energy gel + water
2 hours – 4 ounces sports drink (hour total: 48 grams of carb)
140 minutes- 2 energy chews + water
160 minutes – 1 energy gel + water
3 hours – 4 ounces sports drink (hour total: 48 grams carb)
200 minutes – 2 energy chews
220 minutes – 1 energy gel
4 hours - 4 ounces sports drink (hourly total: 48 grams of carb)