Don’t neglect your fuel plan on your next long-distance race—these guidelines can help power you through the finish line
Photos by Samantha Ong and Javier Lobregat
They say that getting to the starting line of an Ironman is half the battle. If you did your training right, it’s all about executing the race plan.
But what is the best race plan really? Do we go by feel? Do we keep an eye on heart rate? How much do we need to eat? Over the next few weeks, we’re going to tackle these all-important points as you get ready for your first big race in two years.
In this first edition, we’re going to focus on a key aspect of long-distance racing that doesn’t get as much attention as it should: race nutrition.
When we participate in physical exercise, we burn calories and to perform adequately, we need to replenish these calories to a certain extent. To keep things simple, during aerobic exercise (i.e. events lasting more than a couple of minutes), we rely on both carbohydrates and fat as our main fuel sources.
One thing you should remember is that as intensity increases, so does our reliance on carbohydrates. Now here’s the problem: We have a very limited repository of carbohydrates in our body. During intense exercise, we only have enough carbohydrates to last a couple of hours or so. This obviously becomes a problem for long events such as an Ironman.
What about fat? Luckily, we have enough fat to last us several weeks. However, the caveat is that we need carbohydrates to adequately utilize these fat stores. On top of this, going slower doesn’t guarantee we’ll utilize fat exclusively and preserve our glycogen stores. Even at very low intensities, the body still needs some carbohydrates to get the “flame” going. If we run out of carbohydrates, we’ll “hit the wall” or experience that dreaded bonk.
Technically, the body can burn fat in the absence of carbohydrates through a process called ketosis. Yes, it’s what “keto diets” refer to when we consume meat and protein while limiting carbohydrates.
But here’s the problem with that concept for endurance sports: Unless we’ve properly prepared our “ketogenic engine,” we’re going to have a very difficult time producing energy from ketosis the same way we would from our krebs cycle (the carb-fat engine we were previously talking about).
Think of it as a backup generator when our body runs out of carbs; it’s not going to have the same capacity as our main power plant. Take note that some people might have an easier time with this depending on the length of experience they had with keto diets and possibly other factors such as genetics but at the end of the day, most people would struggle with this approach (albeit unnecessarily).
What’s the solution? Replenish carbohydrates as we go along. Paying attention to how much we’re taking in will give us enough mileage to get to the finish line! Here are a few tips:
Mix it up
It may be tempting to keep things as simple as possible and consume the same fuel throughout the race but this can be problematic. Imagine eating and drinking the same thing for an entire day. We’ll probably get so sick of it midway into the race such that we don’t even want to ingest it anymore. This also becomes a problem for those going down the liquid route as we need solids to get our digestion going.
Mastication stimulates the digestive tract, thereby making the transit of food and drink faster. We need to give adequate signals to our body so it knows we’re taking in calories and not just water. This is why I recommend alternating between solid and liquid fuel throughout the race.
Focus on carbs
During the race, the fuel we need to replenish are carbohydrates, not fat or protein. Thus, if we allocate too much of our calories to the latter sources, we’re doing a disservice to our body. Think of it as an “opportunity cost” we should avoid. By taking in (too much) fat and protein, we have to sacrifice the space that should have gone to carbs.
On top of this, excessive fat and protein can also lead to gastrointestinal problems later on in the race. However, take note that all fat and protein should not be avoided.
If we’re taking in solids, this is also rather impossible. We need a little bit of those other macronutrients to help keep our digestive and metabolic processes functioning well. Just make sure these are all within reason.
I know, it’s tempting to fuel up with candy bars, sweets, soft drinks, and whatnot during the race. Must be heaven to go on a chocolate and dessert buffet, right? Definitely not.
The problem with ingesting too much sugar during the race is that one, it can lead to “osmotic diarrhea.” This is what happens when we take too many gels and sports drinks, thus causing us to rush to the toilet. When this happens, not only is it an unpleasant experience, we also lose a lot of water and electrolytes in the process.
The second problem is the fact that we experience sugar crashes when we take in too much sugar. This leads to a spike and dip in energy levels caused by our body’s last-ditch effort to regulate sugar levels in our blood stream. This is not desirable as not only does it make motivation and proper pacing difficult, it can also potentially lead to long-term problems when done regularly (i.e. type 2 diabetes).
Take in enough calories
In general, 200 to 300 calories of carbs per hour are needed during an Ironman. These values vary from person to person since size and weight, carbohydrate dependency, pacing, and athletic capabilities influence the overall nutrition plan of each person.
In general, the best way to determine this is via metabolic testing, which we do in the lab. By measuring respirated gas, we can accurately determine the best nutrition plan for each athlete. However, without it, we are left with a lot of guesswork.
I recommend starting with a lower number and working your way up depending on whether you feel energy stores deplete during longer workouts. Remember, after swimming almost 4 kilometers, and biking 180 kilometers, you still need to run a marathon. Make sure your body is ready for the final deciding leg.
Practice your fuel strategy
At the end of the day, it all boils down to this: We can have the best nutrition plan but if we fail to practice it prior to race day, we’re setting ourselves up for disaster.
Not only does our body need to get used to the fueling and hydration plan, we also need to check the feasibility of the fuel we’re planning on taking with us.
Some might be too bulky, some might spoil easily, others might not feel that appetizing after spending hours under the sun. Remember to insert some big day workouts and rehearse your nutrition plan during these sessions. In doing so, you can make the necessary adjustments for the actual race.
Have some training questions, feedback or suggestions for future articles? Drop a note in the comments section below or on Facebook, Twitter or Instagram. You can also get in touch with Don directly here.