Your Guide to Carbohydrate Loading for Peak Performance
Today’s blog delves into the science and practice of carbohydrate loading (carb loading) for optimal performance. Whether you're an endurance athlete or just engaging in functional fitness, it’s one a few important nutrition strategies, and understanding carb loading can significantly enhance your performance.
By maximising your muscle glycogen stores through strategic carbohydrate consumption, you can sustain energy levels for longer, boost your athletic output, and smash more personal bests.
Let's explore what exactly carb loading is, why it’s so essential, and how to effectively implement it into your nutrition plan for any event, be it a triathlon, marathon, or even an ultra. We’ve got you covered.
What is Carbohydrate Loading?
Simply put, carb loading is the strategic consumption of a high carbohydrate diet in the day or days leading up to a competition or race. By increasing your intake of carbohydrates, you can aim to saturate your muscle glycogen stores, which are crucial for sustaining energy during high intensity and endurance activities.
Why Carbohydrate Loading Matters
The main reason so many people partake in carbohydrate loading is to, quite simply improve performance.
Glycogen, stored in muscles and the liver, is the body’s predominant fuel source during intense exercise. Athletes with higher glycogen stores can sustain their energy levels longer and perform better, in fact carb loading has been shown to improve time to exhaustion by about 20% and has been able to enhance performance in time trials by 2-3%.
This is particularly significant for endurance events when those percentages can add up to large chunks of time taken out of your race.
How to Carb Load: The Science Behind It all
Historical Perspective: The Supercompensation Protocol
In 1967, sports science researchers Bergstrom and Holtman proposed the "supercompensation" protocol, which involved glycogen depletion through a period of intense training followed by a low carb, high fat, high protein diet for three days. This was then followed by a high-carb diet for three days, and it resulted in super high muscle glycogen concentrations.
Despite its effectiveness, this method is impractical due to the difficulty in adhering to extreme dietary changes and the risk of hypoglycemia. Because of this it’s rarely used today and instead athletes take a more realistic approach to carbohydrate loading.
Modern Approach: Practical Recommendations
Diagram taken from the BRILLIANT Asker Jeukendrup at www.mysportscience.com
Based on the latest guidelines from the International Society of Sports Nutrition and leaders such as Louise Burke and Asker Jeukendrup, here are some practical recommendations for carb loading:
Carb Loading For Events Less Than 90 Minutes
Consume 7-12 grams of carbohydrates per kilogram of body weight in the 24 hours leading up to the event. For example, a 75kg athlete should consume between 525 and 900 grams of carbohydrates. Choose an amount that is manageable and comfortable for your body, so if you’ve never carb loaded in this way then perhaps aiming for the lower window of 7 grams per kilo to start with. It’s also worth prioritising carbohydrates that are relatively easy to consume so low in fibre and potentially even liquid carbs.
Carb Loading For Events Longer Than 90 Minutes
Consume 10-12 grams of carbs per kilogram of body weight for 36-48 hours before the event. For a 75kg athlete, this means 750-900 grams of carbohydrates each day for two days. To really maximise glycogen storage, opt for high glycemic index carbohydrates that are low in fibre to avoid gut stress.
It could also be useful to ramp your intake up across this period so as to limit the potential for gut upset, for example you may consume 10 grams of carbs per kg 2 days out from an event and then up it to 12 grams per kg the day before. It’s also worth noting that these are simply guidelines and different athletes will be able to tolerate different amounts of carbs pre event.
Again because the amount of intake is so large some liquid carbohydrates may be needed! With both of these protocols it should be noted that practicing this level of intake before hand will help make sure the athlete can take it on and won’t be thrown off by guy issues or a potential disruption to sleep.
Refuelling During Events
Carbohydrates Between Events
In competitions with multiple events in a day, refuelling is crucial. Post-event, consume 1-1.2 grams of carbohydrates per kilogram of body weight per hour for four hours. For a 75kg athlete, this translates to 75-90 grams of carbohydrates every hour, totalling 300-360 grams in four hours. This amount of carbs might seem like a lot, so again it’s important to go for sources of carbohydrates that are relatively easy to consume and low in fibre!
If this amount is impossible to take on in that time frame then finding a compromise that still ensures some carbohydrates are taken on is worth trialling. Even if it’s just a case of some easy to consume carbs immediately after and doing what you can in between.
During Events
For events lasting 1-2.5 hours, aim for 30-60 grams of carbohydrates per hour. For longer events such as marathons or Ironman competitions, aim for 90 grams per hour or more. High glycemic index options like sports drinks, gels, or sweets are ideal. As with carb loading itself, different athletes will be able to tolerate different levels of intake. It’s also always worth trialling the carbohydrate intake you’ll be aiming for on the day before the event to mitigate ant issues. Never try anything new on race day.
For some events it may even be worth pushing intake further still to 120g/hour. This will be particular useful in events that don’t result in much jostling. For example ultra endurance sessions on a bike, it’s easier to tolerate more carbs than when running.
You should also look to mix up the type of carbohydrates your consuming, looking for products that have both glucose and fructose to increase absorption, and altering between solids, liquids and gels. It’s also worth having some savoury options in case the sweetness becomes too much to take!
Personalisation: The Key to Effective Carb Loading
While the above recommendations provide a general framework, individualisation is essential. Each athlete's body responds differently to carbohydrate intake. Working with a nutritionist can help tailor these guidelines to your specific needs, ensuring optimal performance and comfort.
Some athletes may prefer to take on liquid carbs, others solids, and some may tolerate large amounts well whilst others poorly. Some of this may be trial and error but a nutritionist can help guide the way to ensure that your carbohydrate loading and fuelling is tailored entirely to you, the athlete.
Practicing Your Carb Load
Practice your nutrition plan during training to find what works best for you, competition/race day simulation sessions and training the gut are incredibly important to ensure the event goes smoothly on the day.
Experiment with different types and amounts of carbohydrates to determine what your body can handle without adverse effects. This preparation is crucial for avoiding surprises on race day, so you should always practice your carb intake.
Never try anything new on race weekend! You need to be confident that you have the fuel you need to perform and that it’s well tolerated. Any changes on race/competition day can throw you off both physically and mentally, as the old adage goes, fail to prepare, prepare to fail!
Conclusion
Carb loading is a powerful strategy to enhance athletic performance, particularly for endurance events. By understanding the science and applying practical recommendations, you can maximise your glycogen stores and boost your performance.
Remember, personalisation is key—work with a nutritionist to tailor your carb loading plan to your individual needs and practice it in advance to ensure that you’ll never bonk again.
Need Help Prepping For a Race?!
At Luke Hall Nutrition, we are committed to providing evidence-based, personalised nutrition plans to help you reach your full potential. Whether you're preparing for a marathon, triathlon, or any other competitive event, our expertise in performance nutrition will guide you to success. Contact us today to start optimising your nutrition and crushing your goals!
