During Ride Nutrition & Hydration: What, When and How Much to Eat

In this nutrition video FasCat's Registered Dietitian (RD), Lacey Rivette, explains your during ride nutrition: How to fuel during your ride, including how exercise intensity and duration impacts how much and what you should be eating, how to assess your fluid needs, and a few of the differences between fueling for males and females. There are also helpful charts and examples to help you better understand how to fuel properly on the bike so you can ride faster, for longer! You can also find those charts (with some bonus ones) in the pdf below.

👉 Download the During Ride Nutrition Charts and Example Fueling Strategies Here 👈

What should be the primary focus of an endurance athletes nutrition plan?

In no particular order (because they work in unison):

1. Carbs
2. Water
3. Electrolytes

So first let's talk about carbs! Carbs are your muscles preferred fuel source during exercise. The body can store around 400-600g of them in the form of glycogen within your muscles, and to a lesser extent in your liver. When riding in zones 2-5, you will be burning around 3-4g of carbs per minute. That means if you do not consume any carbs while you ride, you'll deplete those stores in about 2 hours. What happens then?... the dreaded BONK! This is why carbs are so important for cyclists! Now that you know you need carbs to perform, let's talk about how much of them you will need.

For a ride lasts about 1- 2 hours athletes should be aiming for around 30-60g of carbs per hour. If the ride is low intensity, athletes can aim for the lower end of the range and can opt for solid foods that are high in carbs such as homemade baked goods, bananas and bars. However once they start to hit high intensities (such as sweet spot and threshold), they should aim for the upper end of the range and fuel with easy to digest carbs such as gels, drink mixes and chews.

For rides longer than 2.5 hours athletes typically need ~60-90g of carbs per hour and it is at this point that the source of carbs really starts to matter. You see all carbs are composed of simple sugars, the two main ones being glucose and fructose. Note: galactose is the third type of simple sugar but it is derived from milk and is not a good choice during exercise as it is harder to digest and competes with glucose for absorption.

Glucose and Fructose are absorbed in the small intestine by different transporters (SGLT-1/GLUT2 and GLUT5, respectively for our biochem nerds out there). The one for glucose can take in about 60g per hour, whereas the transporter for fructose can absorb about 30g per hour though these rates can vary between individuals. Thus for longer rides, athletes need to ensure that their fueling strategy contains roughly a 2:1 ratio of glucose to fructose.

Good news is that while this sounds complicated, you won’t have to try too hard to achieve this as most sports nutrition products already contain that perfect ratio. Take Gu gels for example. They contain a mixture of maltodextrin (underlined in red on the nutrition label), which is a chain of glucose molecules linked together and fructose (also underlined). These gels can be combined with a drink mix that also contains a mixture of fructose and glucose to achieve carbohydrate intakes of >60g/hr. 

Now there are some instances where athletes have been shown to tolerate upwards of 120g per hour, which is why I made note of that on the chart above. An example of this is Sean Gardner who holds the current Everesting Record. He ate 120g of carbs per hour for 7 hours. That is equivalent to consuming a gu gel every 10 minutes! I was curious to know exactly how he managed that much food, so I reached out to him. He said that at the beginning of the ride he consumed mostly solid foods (pop tarts were the weapon of choice) and then he switched to a high carbohydrate drink mix with some gels. This is something ultra endurance athletes should make note of, which is that eating solid food at the beginning of a long event is a smart choice as the gut's ability to digest foods will decline over the course of your ride. 

After talking to Sean, I am now curious to know what and how much Fascat athlete Phil Gaimon will eat on his next attempt to break the Everesting Record. The obvious guess would be a lot of cookies, but something tells me that might lead to some gastrointestinal disturbances...

I digress, the point here is that just because some athletes can consume this amount of carbs, doesn't mean that it will work for you. You need to test out different amounts and types of carbs to see what works best for you based on the type of ride you are doing, what the conditions are like outside and how your stomach responds. Once you figure that out, practice, practice and practice some more so that come race day you aren't trying anything new. If you are unsure of how to apply these recommendations to your rides, check out these example fueling strategies for some inspiration!

Hydration and Electrolytes Now onto the final aspect of your fueling strategy, which is hydration and electrolytes. In moderate environments (around 65 °F/22 °C ), males typically need about 20-36 ounces of water and females about 14-30 oz.

As you can tell that is a pretty big variance and when in hotter environments, fluid needs can exceed this. So I encourage athletes to do a simple sweat rate test a few times a year to better understand their hydration needs in different conditions. To do this, the athlete weighs themselves without clothes on before training, measures how much fluids they consume durig their ride and then weighs themselves again without clothes on immediately after finishing their ride. Then they add up how much weight they lost and how much fluid they consumed and then divide that by duration of their ride and that will tell them how much fluids they should be taking in each hour to offset losses.

 Here is a quick example using lbs and ounces. Note: If you use the metric system, check out the pdf above where I have include this example using kg and milliliters.

Notice that the athlete was consuming less than 1/2 off the fluid that they needed for that ride! The athlete should take note of this and increase their fluid intake in the future so that their performance doesn't suffer. I could go on a rant here about how important hydration is, but I will just leave you with this chart which sums it all up. Moral of the story, dehydration is devastating to your performance!

This gets me into the next topic which is electrolytes, in particular sodium, which is the main electrolyte lost in sweat. Sodium is extremely important as it helps with fluid retention and the absorption of glucose. In colder environments, athletes can typically meet their sodium needs through food.

When riding in warm environments for longer than an hour though, athletes should consume at least 300-500mg of sodium from a drink mix in addition to the sodium from food. Again this is not too hard to achieve as most drink mixes contain that. For example Gu Roctane has 320mg of sodium per serving. Keeping with the theme here, each athlete is different and some may lose more sodium through sweat than others. If that is the case for you, you can opt for nutrition products that have more sodium in them. Gu’s Roctane line is a perfect example of this. All the Gu Roctane gels contain around twice as much sodium as their traditional gels.

Now many athletes find that using a drink mix is the easiest way to meet carb, fluid and electrolyte needs. And I would agree. But I want to emphasize how important it is to read the nutrition facts of each product and the instructions for preparing it so that you do not consume a mix that is too concentrated. For males, drink mixes with up to 10% carbohydrates are usually well tolerated, whereas females tend to do better with one that contains 3-6% carbohydrate.

To explain how you can easily adjust the percent of carbs in a drink mix, lets use Gu Roctane as an example. It contains 60g of carbs per 2 scoops and indicates to mix that with 21 oz of water. This comes out to about 10% carbohydrates with 320mg of sodium which is great for most male athletes. If you are a female and notice that you do not tolerate it when it is that concentrated, you can opt to mix 1 scoop of it with 16 oz of water which would come out to 6% carbohydrates. Since this will mean that your sodium intake will be lower, you can have a Gu Roctane gel and additional water to meet your sodium needs. If you are using a different drink mix or different amounts of fluids than indicated in the above example, you can use this equation to determine the % of carbohydrates in your bottles.

And with that, we have covered the 3 main components of your during ride nutrition. If you have any questions, feel free to leave them in the comments below!