The Countdown Begins: Preloading Carbs & Electrolytes
During a bike race, you can burn about double the amount of calories that you’re capable of digesting every hour. Between the start and finish lines, you can only replace about half of the fuel you burn. This is practically similar (though not identical) to the amount of electrolytes you can utilize vs replace during exercise. The imbalance between what we can use and what we can replace during the race is what leads to cramping and bonking, especially during longer, hotter, and more demanding events.
“…your nutrition and hydration in the 48 hours leading up to the start of your event are just as important as what you will consume during your event.”
While it is common knowledge that you must eat and hydrate to sustain athletic performance, the imbalance between what can be used and what can be replaced during races is often greatly underestimated. Needless to say, your hydration and fueling strategy during events is vital to your success, and optimizing that strategy on a personal level requires experimentation, planning, testing, and execution. However, often overlooked is that your nutrition and hydration in the 48 hours leading up to the start of your event are just as important as what you will consume during your event. Proper nutrition and hydration for a given event starts two days ahead of time. We refer to this two-day window as the “preload” phase.
The purpose of the preload phase is to “top-off” your glycogen and electrolyte reserves. The goal is to have the maximum amount of glycogen and electrolytes possible on the start line, regardless of the duration of the event. This will enable your body to perform at maximum, sustain that performance as long as possible, and give you a small “buffer” in case you miss a fuel or hydration interval during the event. The penalty for underestimating or miscalculating this piece of the process begins with a significant drop in power and endurance, then increases to bonking and/or cramping, and, if left unchecked, can become a serious health issue.
“…7-12g of carbohydrate per kilogram of bodyweight.”
Let’s start with glycogen, or what we all know as “carbo-loading”! For each of the two days leading up to your event, you’ll need to consume 7-12g of carbohydrate per kilogram of bodyweight. For example, if you weigh 150lb (68kg), that means you need to consume 476-816g of carbohydrate for each of the two days leading up to your event. One gram of carbohydrate is four calories, so that works out to roughly 2,000-3,200 calories of just carbohydrates each day for the two days. In the first 36 hours of this 48 window, it is critical that you prioritize complex carbohydrates (such as rice, potatoes, vegetables, and fruit) and regulate or minimize simple carbohydrates (such as added sugar, juice, desserts, and sodas). Additionally, you should regulate or minimize the amount of bread products (such as pasta, pizza, bagels, waffles, and muffins) you consume as part of your preload process, instead prioritizing whole foods (again rice, potatoes, vegetables, and fruit) It is not only acceptable, it is advisable to reduce protein and fat intake in this two-day window to reallocate plate and gut space for the extra carbohydrates. To be sure, many of you consume this amount of carbohydrate on a regular basis during training blocks, but doing so without simple carbs, without a boosted appetite from training, and without ride food is a slightly different challenge.
“Water alone…won’t get the job done.”
The case is similar with electrolytes. Did you know you can utilize over 1000mg of sodium per hour of racing? But, in a best case scenario, we can only replace about 500-700mg of sodium per hour during the race. How do we address the deficit? Preload ahead of time! In a 4 hour race, there could easily be a 2000mg (or 2g) deficit in sodium/electrolytes by the end. It may seem trivial to just add two packets of LMNT the day before or the morning-of, but the reality is that won’t quite get the job done.
Drinking water alone will not hydrate you properly. We need electrolytes for optimal and prolonged muscular performance (avoiding cramps) AND for water retention, enabling you to maintain blood volume (for aerobic performance). Proper hydration is about making sure you have enough electrolytes and water in the right balance. Water follows salt, so we’re trying to make sure we have enough electrolytes to balance and retain the maximum amount of water possible. Increasing the volume on both sides of the scale, in balance, is the key to retention. This process has to happen gradually, as anyone who has chugged a bottle and had to pee 10 minutes later can tell you. While we’re on the topic of urine, clear urine doesn’t necessarily mean you’re properly hydrated. Especially if you’re urinating frequently, that is a clear indicator (pardon the pun) that you don’t have enough electrolytes (salt) to retain that water. It’s a two-way street. Yes, we want to ADD water weight. It makes you faster. Again, water follows salt, so a good way to do this is by simply adding 2-3g of sodium to your baseline (which is 3-5g per day) for a total of 5-8g of sodium per day, two days leading up to your race. We recommend generously salting your food and finding a dense electrolyte supplement (such as LMNT) to get the job done. There are cheaper options out there if you don’t need flavoring, or you could make your own electrolyte blend fairly easily. As for water- between 100oz (¾ gallon) and 192oz (1.5 gallon) per day, depending on your size, is sufficient for preloading purposes. Getting the electrolytes right is more important than getting the water right. You’ll probably need to drink quite a bit to get all the extra electrolytes down anyhow, despite not actually drinking straight water.
Potassium and magnesium need to be recognized here as well. You need potassium at a 1:5 ratio to sodium, and while many electrolyte supplements will contain potassium, if you’re consuming potatoes each day as part of your preload, you should check that box easily. As for magnesium, we recommend taking a supplement regularly anyhow, and there is no change to that routine for the preload phase. It is not necessary to take extra.
Those are the basics of preloading carbs and electrolytes! For what to do on the day of the race itself, see this article!! Ready to optimize your plan? Check out our services!