Race Day Hydration Plan
We’ve done our best to distinguish between salt (sodium chloride) and actual sodium, but there may be instances where the two get flipped. Generally speaking, salt is the term most athletes will use in reference to sodium, and is also used to refer to products like salt tabs, electrolyte salt, etc.
This blog was originally written in 2019, but as we hopefully return to racing in 2021, it still remains true.
A couple of weeks ago, I made a prediction that Ironman Boulder would have a 20% did not finish (DNF) rate due to the heat. This high prediction was based on the colder temperatures most athletes were training in over the winter / spring, and the fact that Boulder is notorious for being hot on race day. Combine this with altitude and you have the perfect storm for disaster.
The DNF rate ended up around 18% (up to 30% including athletes who didn’t start). Of the 18% who DNF’d, I’d wager you $1 that 90% of those were due to an improper nutrition plan – specifically an improper hydration plan. Sponsor provided products available on course for Ironman and Ironman 70.3 branded races, Gatorade Endurance* and Base Electrolyte Salt**, likely exasperated the issues of dehydration.
*Relying on Gatorade Endurance for fluid and sodium is inefficient. By the time you get the fluid / sodium you need, you may overload your GI with sugar – leading to things possibly exiting either up or down – neither way is good.
**Relying on Base Electrolyte Salt for sodium may overload your body on chloride – leading to things possibly exiting…well you know the rest.
In the past three weeks since Ironman Boulder, temperatures have continued to skyrocket across the country. My next wager is that high DNF rates will be seen at future events – especially Ironman Lake Placid* and Ironman Augusta 70.3**. A DNF on race day sucks no matter how you slice it, but when your day ends early due to something you can control, it’s a tough pill to swallow.
*IM Lake Placid will either be cool if it rains, or HOT if it doesn’t rain.
**Augusta 70.3 is like racing on the sun. This year will be worse!
A Little Help for Our Friends
To help you navigate training and racing in extreme temperatures, we’ve put together an optimal hydration plan. While this plan is geared towards iron distance athletes, it can easily be adapted to fit your specific event.
Before we get to the plan, let’s first delve into hydration, the roles of electrolytes (specifically sodium), and how hydration and not just salt is your key to optimal performance.
What is active hydration?
When we say active hydration, we are referring specifically to hydration during exercise. The role of active hydration is to get fluid from your bottle and into your cells and blood. We say “your cells and your blood” specifically because getting fluid into your body (i.e. your stomach) is easy. The tricky part is getting the fluid to where it counts.
Active hydration is comprised of three parts
Not only do each of these components need to be consumed in the proper ratio to one another, but the types of sugars and electrolytes, and the ratio of each type of sugar and each type of electrolyte matter as well.
We will not go into the science, or specifics of each component because this blog would turn into about 10,000 words and be as dry as a PhD dissertation. Luckily for you, there are solid hydration products from reputable companies, such as ClifBar and NBS Nutrition$ that can provide what you need. All you have to do is scoop, mix, drink, and win.
$NBS Hydration can ship to you for as little as $0.32 per serving, or about 30% less than similar products.
It’s not just about salt.
The importance of salt intake has been stressed to endurance athletes for years. If you cramp during training or a race, your first instinct is to reach for the salt. If you tell someone that you cramped during training or a race, the first thing they will tell you is reach for the salt. Unfortunately, salt is not always the answer. The link between salt, specifically sodium, and cramping is murky at best.
NOTE: Here are the reasons we’ve found athletes will generally cramp long before a lack of sodium is the cause:
- Inadequate energy stores to support intensity of effort (think depleted glycogen stores, hammering the bike and getting a quad cramp)
- Physiological issues to include improper equipment fit, improper exercise form (hip flexors cramping on bike or the run) or muscle overuse (tied to inadequate energy stores)
- Improper electrolyte balance
* In the past 2 months we’ve worked with 5 athletes who suffered from premature cramping (cramping that occurs within the first 1/3 of your event). We fixed each of the athlete’s issue with one of the above scenarios, while decreasing their overall sodium intake by an average of 280 mg. per hour.
The majority of salt and electrolyte products marketed to endurance athletes are sodium chloride. Sodium chloride is plain table salt. The salt product available on Ironman courses is pink Himalayan sea salt, which is a more raw form of sodium chloride.
Is it bad to ingest sodium chloride while racing? No and yes. Consuming some sodium chloride is good since chloride plays an important roll in proper hydration. With that being said, consumption of sodium chloride may result in:
- Dehydration – Excess sodium chloride to water intake is like drinking sea water (watch this video). Essentially your body becomes so concentrated with sodium chloride that it dehydrates you by pulling water from your cells. When the fluid from your cells gets trapped, it can cause edema*.
- Extra Port-O-Potty Stops – Excess chloride intake may lead to a whole host of issues, the least of which is GI distress.
- Electrolyte Imbalance – An improper balance of sodium to potassium will cause your body to start releasing hormones to bring your balance back to normal. This causes you to flush out excess sodium**.
* We’ve seen 3 cases of edema in triathletes in the last month caused by too much sodium chloride.
** The white crust you see on an athlete’s kit during a race is usually caused from excess sodium being flushed from the body, and not because the athlete is sweating out crucial sodium stores.
Again, some sodium chloride is not a bad thing. You will likely get more than enough from your fuel source of choice. If for some reason your fuel source is low on sodium, you can add in some sea salt$, or plain table salt. However, we suggest adding it to your fuel instead of taking it in pill form. For example, you can mash some sea salt into your favorite bar or sport chew$$.Eating salty foods will drive thirst and cause you to automatically consume some liquid. While taking sodium in pill form will not drive thirst, and may lead to ingesting too much salt for the GI tract to handle.
$Costco sells 5 lbs. of pink Himalayan sea salt for less than $7.
$$Roll fruit snacks in sea salt – BOOM – instant sport chew.
$$$Stop at a fast food place and buy a small cup of coffee the morning of your event. On your way out the door, grab a handful of salt packets.
Hydration for the win.
If it’s not about the salt, then what is it about? Ultimately, your body’s fluid level will be what makes or breaks you on race day. The only way to maintain an optimal body fluid level is through proper hydration. So, the name of the game becomes fluid maintenance – keeping your body’s balance of water and electrolytes (mainly sodium and potassium) as close to its natural state as possible. Don’t get me wrong, if you are competing in ultra events (anything over 8 hours) you will end up losing some of your stored water and electrolytes (more on this later). While it’s not possible to consume as much as you lose during these long events, the key is to stay within a range of fluid loss that doesn’t affect your performance.
How do you know how much fluid you should consume while racing? For us, it all starts with a simple test.
- Pick a day when you will be performing a workout at race intensity in conditions similar to your event.
- Once you are set and ready to go, get on the scale and weigh yourself naked and record your pre workout weight.
- After your workout, strip down, dry off, get on the scale and record your post workout weight.
- Add up how many ounces of fluid you consumed and divide it by 16, because 16 fluid ounces is approximately 1 pound. This will give you the amount of fluid you consumed in pounds.
- Add together the weight of the food you consumed in grams (check packaging for these weights) and divide it by 454 because there are 454 grams per pound. This will give you the amount of food you consumed in pounds.
- Subtract your post workout weight from your pre workout weight.
- Next, take the difference between the two and add your fluid consumption (in pounds) and your food consumption (in pounds). This is your total fluid loss (in pounds).
- Divide this number by the amount of hours of the workout to get your fluid loss (pounds) per hour.
- Multiply your fluid loss (pounds) per hour by 16. This gives you your fluid loss per hour in ounces.
Confused yet? I hear ya…words and math do not belong together. Let’s take a look at a sample athlete.
Here’s the data from our athlete:
Pre workout weight (PWW) = 150 pounds
Post workout weight (PTWW) = 148 pounds
Fluid consumed (FLC) = 32 ounces = 2 pounds (32/16)
Food consumed (FDC) = 136 grams = .3 pounds (136/454)
Workout duration (WD) = 2 hours
PWW (150) – PTWW (148) = 2 pounds
FLC (2) + FDC (.3) + 2 (difference between pre and post) = 4.3
4.3 / WL (2) = 2.15 pounds per hour
2.15*16 = 34.4 ounces of fluid lost per hour (FLPH)
Matching Fluid Consumption to Fluid Loss
Now that we know our fluid loss, the goal will be to either match, or get as close to our fluid loss with our fluid consumption. After testing, we determine our sample athlete from above can consume 28 oz. of liquid per hour (FIPH) consistently with zero risk of GI issues.
Why not just match fluid consumption to fluid loss? It may not be possible as your stomach has a limit on how much it can process per hour. Most female athletes will start with a consumption rate of 20 – 25 oz. per hour. Most male athletes will start with a consumption of 25 – 30 oz. per hour. Factors such as body weight, exercise type and exercise intensity will influence consumption rates.
NOTES: There will ALWAYS be outliers. We have females who consume 38 – 40 oz. per hour, and males that max out at 22 oz. per hour. You’ve got to find out what works best for you as an individual.
Now we can determine if our athlete’s fluid loss vs. fluid intake will keep them within an optimal range of fluid deviation*. We use 2% of an athlete’s body weight as our margin of error since we know that we can lose up to 2% of our total body weight without any real impact on performance.
*We define fluid deviation as a set standard of acceptable fluid loss.
Our athlete weighs 150 lbs. so their fluid deviation is 2% of 150 lbs., which is 3 lbs. Our goal is to keep them as close to a 3 lb. fluid loss as possible, while making sure all of the components of active hydration are met. If our athlete has an event goal time (T) of 12 hours, we can now figure out what their total fluid loss would be over the course of their event.
Total Fluid Loss (TFL): (T) 12 * (FLPH) 34.4 = 412.8 oz.
Total Fluid Intake (TFI): (T) 12 * (FIPH) 28 = 336 oz.
Total Fluid Deviation (TFD): [(TFL) 412.8 oz. – (TFI) 336 oz.]/16 = 4.8 lbs.
From our calculations, our athlete will lose 4.8 lbs. or 3.2% of their body weight over the course of their event. While this is outside of the 2% deviation, it is within 5% of total body weight, which is the threshold where performance can be severely impacted. We wouldn’t worry too much since we know some tricks to buffer water loss. We will get into that during our Optimal Hydration Plan.
Now that we are confident in our athlete’s fluid loss and fluid consumption, we will look at total sodium intake. Remember when we said that sodium intake would be DIRECTLY related to your fluid intake? Now we can ensure our sodium loss vs. sodium consumption is optimal and within an optimal ratio to our fluid intake.
Sodium Loss and Sodium Consumption
When we sweat we lose sodium, but just how much? The majority of athletes will lose somewhere between 500 and 1,000 mg of sodium per liter (about 33 ounces or roughly 2 pounds) of sweat. Again there are outliers, but finding an athlete that loses more than 1,000 mg of sodium per liter is rare.
NOTE: There are factors that can drive sodium losses up, mainly lack of acclimation. Think training all winter and spring in cooler weather then going to altitude at IM Boulder where it is oppressively hot. Lack of acclimation can increase your sodium loss by 200 – 400 mg per liter per hour.
The majority of athletes will fall in the 500 – 750 mg. of sodium per liter range. Let’s say our athlete loses sodium on the upper end at 750 mg of sodium per liter of sweat. Since we know our athlete loses 34.4 oz. of sweat per hour or 1.04 liters per hour, we now know our athlete is also losing about 780 mg. of sodium per hour (1.04 * 750).
In addition to replacing lost fluids, we need to look at replacing this lost sodium. Let’s assume our sample athlete is consuming 28 oz. of fluid in the form of NBS Hydration. Their 28 oz. per hour contains 525 – 630 mg of sodium* (depending on male vs. female formula). Our athlete is also consuming a fuel source that contains 210 mg of sodium per hour. This means their total sodium consumption is 735 – 840 mg of sodium per hour. They have already met or exceeded their sodium loss without having to worry about ingesting salt tabs, electrolyte salt, or any other product that could end up causing distress. Even though our athlete is meeting or exceeding their needs, we still have to check our sodium to fluid ratio to make sure it is within an optimal range. As a rule of thumb, we keep our sodium intake below 1,000 mg of sodium per 33 oz. of fluid consumed. If for some reason we find an athlete needs to go outside of that range, we are very careful to monitor them for signs of distress caused by excess sodium.
*NBS Hydration uses sodium citrate. This form of sodium is absorbed better by the body and is easier on the stomach.
Since our athlete is consuming .85 liters per hour (28 oz. / 33 oz. per liter) and has a sodium intake of 750 – 855, we know their sodium intake per liter is 866 – 990 mg. They are within range so all the boxes are checked.
Fluid and sodium loss are exponential, not linear, in terms of per hour losses over the course of an ultra event. This means that your losses will increase as time progresses. We won’t worry about that because we are going to take out insurance leading up to the event. Enter NBS Preload!
Optimal Hydration Plan
If you’ve made it this far, and your brain isn’t fried from all the algebra, we thank you. Now we can get down to reason you are here.
Below is an actual plan for one of our female* athletes who indeed weighs 150 lbs. This plan is structured similarly to the 2000+ Race Day Nutrition plans we’ve written that have fueled athletes** through just about every major endurance event on the planet. Please know a ton of data that went into this.
**Each plan for our athlete’s is specific to them. There will be some similarities, but our goal is to follow the evidence specific to you – no matter where that takes us.
Before we delve into the detailed plan below, it’s important to know that this specific plan WILL NOT work for everyone. We wish that it would, but that’s just not how it works. With that being said, we are confident that anyone can take this plan, adapt it to their specific needs and find great success.
Athlete Background / Info
Fluid Loss per hour: 34.4 oz.
Fluid Intake per hour: 28 oz.
Sodium Intake per hour: 750 mg
Event Type: Ironman Triathlon
Event Duration: 12 hours
Event Day: Sunday
Event Start Time: 7 am
*Average training weight.
Hedging Our Bets
Earlier we hinted at ways to increase fluid and sodium stores prior to your event to help mitigate losses. The way we increase our stores is through fluid / sodium loading. The way we load said stores is by consuming NBS Preload. (If you are unfamiliar with Preload, click here to check it out).
Now, you will notice that our athlete weighs 150 lbs., which we noted as her average training weight. We say average training weight because on race day her weight will shift up to around 155 pounds. The reason it shifts up is due to full glycogen and water stores. PLEASE do not worry about race day weight in terms of power to weight ratio. The mindset of the less you weigh the faster you go is not always correct. I promise you the extra 5 pounds of fuel (glycogen and water) will make her and YOU a lot faster.
Remember when we said our athlete’s finishing weight would be about 4.8 lbs. less than when they started? Well, we just gave her back those 5 pounds in water weight. Theoretically, she will finish the race close to her normal training weight.
Race Day Plan
Water Intake: .05 – .75 oz. of water per lb. of body weight (75 – 112.5 oz.). The best option would be to put all of your daily water in a container with 4 tbsp. of hydration mix. You want your urine to be light yellow. If it is completely clear, back off your hydration amount.
Salt Intake: normal. Do NOT over-salt your food.
Water Intake: 50 – 90 oz. – same protocol as Friday. The difference in fluid intake will be made up through NBS Preload starting 12 hours prior to the event.
Salt Intake: normal. Do NOT over-salt your food.
NBS Preload – 2 tbsp. mixed with 16 oz. of water
*Loading should normally occur within 12 hours of the start of your event. Excess sodium and water outside of the 12 hours can leave you bloated and with heavy legs.
NBS Preload – 1 tbsp. mixed with 8 oz. of water
Sunday, upon waking
NBS Preload – 2 tbsp. mixed with 16 oz. of water
Sunday, pre race breakfast
Begin sipping a bottle of hydration.
Sunday, 1 hour prior to race start
NBS Preload – 1 – 2* tbsp. mixed with 8 – 16 oz. of water
*This athlete can consume 7 servings of Preload prior to her event. This amount is specific to her. You must test your tolerance for the product as excess sodium bicarbonate can affect some athletes.
Sunday, 1 hour prior to 30 min. prior to race start
Sip plain water to keep mouth wet as needed.
Swim – none
T1 – none
The bike is a calorie and fluid delivery system. Its main function is to set you up for a successful run (for you triathletes). The better your plan is on the bike, the better your run will be.
0 – 15 min.
Sip plain water to wash your mouth out let your stomach settle from the swim.
It’s a good bet you swallowed some water during your swim. If the swim was in the ocean, the plain water will help dilute any salt water you swallowed.
15′ until 30′ before T2
At this point, our athlete will start their fueling and hydration plan. Their hydration plan includes 28 oz. of NBS per hour, along with plain water from the course. Plain water is to be used as needed, and to pour on the torso to help keep body temperature down. Their fueling plan will provide the remainder of the sodium needed to hit the target of 750 mg. per hour*.
*This plan puts their sodium intake at 884 mg. per liter of fluid consumed.
T2 – Tricks of the Trade
Preload – 1 – 2 tbsp. mixed with 8 – 16 oz. of water*.
*Again, test this out before race day. Not all athletes can slam back Preload in T2 and then go run a marathon.
NBS Carbo•Hydration – 2 – 3 servings with 20 – 24 oz. of fluid taken over the course of T2 – mile 2 of the run**.
**We have gone to great lengths to test Carbo•Hydration. Our initial testing protocol found that when athletes were dehydrated to 5% loss of total body weight, and consumed 3 servings of Cabo•Hydration in 24 oz. of fluid (total time to consume – 2 min.) their power output while cycling returned to pre dehydration levels within 10 minutes.
***We have also tested the above recommendation at standalone 5k running effort, sprint triathlon effort, Olympic triathlon effort and multiple Ironman finishes.
The motion of running makes it hard for most athletes to consume as much fluid during the run as they did during the bike. This means we will have to adjust the run plan down to fit what the stomach can handle in terms of volume*. The adjustment in fluid means the sodium intake will need to shift down as well**. This is where the combination of fluid + sodium loading pre event, a perfectly executed bike plan and the T2 tricks will come to fruition. As an added bonus, you won’t have to run 13 plus miles with a sloshing belly.
*Most athletes will be around .75 – .9 of their bike fluid intake
**You will run (pun intended) a dangerous game if your sodium (especially salt) intake starts getting to the 1.5g per liter mark.
Our athlete will consume Carbo•Hydration and water at each aid stations 1 and 2.
If you do not use of the T2 tricks, start your fueling and hydration plan here.
Same as mile 1 for our athlete.
You keep sipping and consuming.
Mile 3 – Finish
This is where our athlete will begin to execute their plan of 22 oz. of fluid per hour and a sodium intake of 650 mg. per hour*.
*This puts her sodium to fluid ratio at 975 mg per 33 oz.
We will not lie and say the marathon is not going to be without its woes. At some point in time your body may rebel a little – it’s just the name of the game. Ironman racing is a tough game so you have to be prepared to suffer a little. But, we are confident that following a carefully outlined plan will shift your suffering away from GI issues and more towards pushing yourself to new heights.
There you have it. We hope this information helps you better understand optimal hydration and how to create an optimal hydration plan for yourself. If you are still a bit confused on how to adapt this plan for you or your event, we want to help.