Carbohydrate intake during cycling competition in combination with ample glycogen stores heading into competition, are key factors in preventing fatigue and optimizing performance. Falling short on energy can lead to hitting the wall and choosing the wrong foods can lead to gastrointestinal (GI) distress. Giving your sports nutrition the attention it deserves will pay dividends in your training and racing performances.
Training is the time to test the quantity, composition, and timing of your nutrition and increase your tolerance for absorbing higher amounts of carbohydrates should this be required.
The duration and intensity of your races will factor into your carbohydrate needs. Short and intense races can deplete glycogen quickly as carbohydrate is the main fuel source for high-intensity sport. However longer races also rely heavily on carbohydrates. Race-winning moves will be intense even later on during these events and finishing sprints will demand intensity and fatigue resistance.
30 minute -1 hour races
Short and intense races can deplete glycogen stores quickly as carbohydrate is the dominant fuel source for high-intensity sport.
Brian Truman - Road Cyclist - The RAAS
Water will likely suffice for most during short intense competitions. You’ll want to arrive at competition with good glycogen stores from the previous days’ nutrition and your breakfast. However there are other options beyond water which may positively improve your performance.
Carbohydrate Mouth Rinse
During a short even like this a carbohydrate mouth rinse, without swallowing, may improve mean power output. Although the mechanisms remain unclear it appears the performance effect is a result of communication between carbohydrate receptors in the mouth and our central nervous system. Essentially your brain is getting messages sent to it. A carbohydrate mouth rinse can lower our perception of pain and/or send messages to muscles leading to additional recruitment of muscle fibers.
Small portion of carbohydrate:
Although you’ll have good glycogen stores for an event of this duration based on your planned nutrition intake leading into the race, consuming a small bit of carbohydrate such as a gel with water or a few chews during the event is not detrimental to performance and may improve performance through similar mechanisms as a carbohydrate mouth rinse . Do what you’re comfortable with and what works best for you based on your training experience.
1-2 hour races
Once you’re competing in races lasting 60-120 minutes, carbohydrate intake during the race in combination with your glycogen stores leading into the event become more critical for preventing fatigue and improving performance. Examples of races that fall into this time frame include mountain bike races , circuit races, some cyclocross races and longer criteriums.
Gunnar Holmgren – U23 Mountain Bike World Championships 2020: Photo Credit Caroline Gautier
Aim to consume between 30 – 60 grams of carbohydrates per hour from either single carbohydrate sources (ex. glucose) or multiple transportable carbohydrate sources (ex. Glucose, sucrose and fructose) for events of this duration.
Sports drinks with 4-8% carbohydrate are recommended as a quick source of energy and hydration.
Most sports drinks have approximately 20-30g of carbohydrates per serving, while some newer ones on the market such as Maurten, have as high as 80g per serving and have been successfully used by well-trained athletes during competition.
Examples of easy-to-digest carbohydrate sources with 30-60g could include any of the following in different portions.
gels (25-30g)
sports drinks (20-40g)
bread and jelly
dates (too many may cause GI distress)
waffles
energy chews
home made cookies low in fat/fiber
rice crispy squares
home made rice bars
potatoes
Stick with low fat, protein and fiber carbohydrates which are easy for you to digest while racing.
Practical Tip: Races in this category often have very technical aspects. Make sure you pre-ride the course and figure out where you can eat/drink on each lap. Technical mountain bike races can be a challenge and often the feed/tech zone is the key location to fuel. For long criteriums or circuit races, you’ll get a sense of the flow once the race starts and find your best feeding spots.
2-5 hour races
Now we’re in the territory where your carbohydrate intake can make or break your performance. At a race pace of this duration, you’ll want to begin with ample glycogen stores and a game plan for carbohydrate intake during the race to prevent fatigue and maximize performance.
Miriam Brower - Professional Road Cyclist - The Cyclery Racing Team
The range of carbohydrate intake recommended for this duration of time is 60-90g/ hour, however, some well-trained athletes are successfully pushing beyond this to intakes as high as 100g/hour.
In these longer competitions consuming a blend of carbohydrate types becomes especially important as does palatability and gastrointestinal comfort. (More on this later)
Examples of 80g of carbohydrate per hour could be:
1 sports drink (30g) + 1 gel (25g) + 1 banana (25g)
1 sports drink (30) + 1 baked potato (30) + 1 gel (20g)
1 sports drink (20g) + 1 home made rice bar (30g) + Energy chews (30g)
Practical Tips: With this much carbohydrate intake, learning what you tolerate becomes increasingly important. Set up some “mock” race days on longer training sessions and test out different foods that you’ll actually bring to race. Often athletes train with one food and race with a totally different food. Eat the actual foods you’ll race with in the amounts you’ll race with to train your gut. You don’t have to do this for every ride, but it is important to know that you tolerate the quantity and type of food/drink.
Intestinal Absorption and Training Your Gut
Carbohydrates enter the intestines through different transport pathways. Our GI tract is able to absorb anywhere between 1-1.2g/min of single carbohydrate sources such as glucose which equates to 60-72g per hour.
Since different carbohydrates use different transport pathways, when you combine two different carbohydrates, glucose and fructose for example, you are able to increase the amount of carbohydrate that can be taken up by the GI tract as you are now depending on two different transport pathways. This in turn helps us to increase the amount of carbohydrate we can oxidize or utilize during longer exercise durations.
If you’re consuming more than 60-70g of carbohydrates per hour, you’re depending on multiple transportable carbohydrates. With the addition of fructose for example, you can increase uptake to 1.7g/min or 102g/hour. As you increase your carbohydrate intake you run the risk of gastrointestinal upset, however evidence shows that your guts can likely be trained to improve tolerance to these higher intakes.
YES PLEASE!!!!!!!!!!
World record marathon holder and Breaking Two phenom Eliud Kipchoge has competed successfully while consuming 100g of carbohydrates per hour. As a well-trained athlete consuming a high carbohydrate diet, you can train your gut to absorb and utilize more carbohydrate, however these are tactics you’ll want to experiment with during training. More on training the gut here.
A recent study involving mountain runners who consumed as much as 120g/hour of carbohydrates found that intakes of this magnitude could limit metabolic fatigue and improve recovery. This is a newer territory that exceeds the current recommendations of 90g/hour for events over 3 hours in duration. However it does appear possible you can train your gut and as we know, science is always evolving.
Take-Home Message
There’s a lot of fear in the sporting community about carbohydrate consumption, but the data are clear that it does improve performance in endurance sports such as competitive cycling, which includes a wide range of disciplines.
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Learn what works for you. Remember, training is testing time and race day is the day you put all of your learned experiences together to execute your best performance. It’s satisfying to know you put in the work and paid attention to the details and it’s also empowering and builds confidence. Do the work.
You don’t leave your training to chance, so why leave your sports nutrition to chance? Line up with every tool you can to give yourself the greatest opportunity to have your best performance when it matters most, on race day.
Need help with your sports nutrition this season? Start paying attention now to maximize your training plan. Contact me here and arrange a consult with one of our sports nutritionists today!
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Wind at your back, eyes up the road, KEEP ON MOVING MY FRIENDS!
References:
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3. Stellingwerff T, Cox GR. Systematic review: Carbohydrate supplementation on exercise performance or capacity of varying durations. Appl Physiol Nutr Metab. 2014;39(9):998-1011. doi:10.1139/apnm-2014-0027
4. Sjukhus E. Diet, Muscle Glycogen. Acta Physiol Scandanavia. 1967;1967(71):140-150.
5. Vigh-Larsen JF, Ermidis G, Rago V, et al. Muscle Metabolism and Fatigue during Simulated Ice Hockey Match-Play in Elite Players. Med Sci Sports Exerc. 2020;52(10):2162-2171. doi:10.1249/MSS.0000000000002370
6. Brietzke C, Franco-Alvarenga PE, Coelho-Júnior HJ, Silveira R, Asano RY, Pires FO. Effects of Carbohydrate Mouth Rinse on Cycling Time Trial Performance: A Systematic Review and Meta-Analysis. Sport Med. 2019;49(1):57-66. doi:10.1007/s40279-018-1029-7
7. Turner CE, Byblow WD, Stinear CM, Gant N. Carbohydrate in the mouth enhances activation of brain circuitry involved in motor performance and sensory perception. Appetite. 2014;80:212-219. doi:10.1016/j.appet.2014.05.020
8. Viribay A, Arribalzaga S, Mielgo-ayuso J, Castañeda-babarro A. E ff ects of 120 g / h of Carbohydrates Intake during a Mountain Marathon on Exercise-Induced Muscle.
9. Costa RJS, Miall A, Khoo A, et al. Gut-training: the impact of two weeks repetitive gut-challenge during exercise on gastrointestinal status, glucose availability, fuel kinetics, and running performance. Appl Physiol Nutr Metab. 2017;42(5):547-557. doi:10.1139/apnm-2016-0453
10. Miall A, Khoo A, Rauch C, et al. Two weeks of repetitive gut-challenge reduce exercise associated gastrointestinal symptoms and malabsorption. Scand J Med Sci Sport. 2018;28(2):630-640. doi:10.1111/sms.12912
11. https://runningmagazine.ca/health-nutrition/kipchoges-berlin-nutrition-plan/
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