For endurance athletes, carbs are vital for maximum performance. If you want to go fast, you’ve got to have sugar onboard. Whether you’ve got a big training day or event, these carbohydrate nutrition tips will help.
For more information on nutrition and recovery check out Ask A Cycling Coach Ep 244
Carbohydrates and Glucose
It is hard to overstate the importance of glucose for aerobic performance. This simple sugar is used by the mitochondria to produce ATP, which is the energy source for aerobic activity. All forms of carbohydrates you ingest are eventually converted to glucose. When your body has more glucose than it needs, it is converted to glycogen and stored in the muscles and liver.
When glycogen stores are full, the liver converts the glucose to triglycerides, which goes to fat storage. The good news is that through training, you can increase the amount of glycogen your muscles can store. Peak endurance performance is all about managing these energy stores, which highlights the importance of the amount and timing of your nutrition.
Carbs Before Your Ride
Ingesting carbs before your workout or event is crucial for peak performance. The goal is to ensure sufficient glycogen stores are in the liver and muscles for the work that you are going to do. Fortunately, it’s easier to fully stock your glycogen stores if you’re eating well in advance of your event because it can be accomplished by eating regular meals.
Aside from fueling your ride, multiple benefits stem from eating hours, if not days, beforehand. There is less chance of GI distress because you are consuming the carbs incrementally. That is, you are getting them the usual way, with conventional foods. By utilizing regular meals to top off glycogen stores, you can emphasize nutritional content like minerals and vitamins. Additionally, you can carb load for a big training day or event.
Time of Absorption
Before your ride, carbohydrate absorption is mostly reliant on your level of glycogen depletion, rate of ingestion, and the type of carb. The lower your glycogen stores, the faster carbs will be absorbed.
What and When Should I Eat
The more complex the carbohydrate, the longer it takes to be digested and absorbed. Whole grains and beans take a couple of hours, while potatoes are a bit quicker at an hour. Fruit and vegetable absorption times are mostly dependent on fiber content. More fiber means longer times, but 20-40 minutes is usually sufficient. It’s important to remember that ingesting protein and fat will lengthen this timeline. A good rule of thumb leading into an event is to eat a carb-centric meal 3-4 hours beforehand. The timeframe can be shorter depending on the complexity of the carbs in your meal. This gives your body ample time to digest and absorb the carbohydrates.
Carbs During Your Ride
Eating during your ride is all about fueling the muscles for the work you are doing. Because you need these carbohydrates to get to work quicker, a simple carbohydrate is best. These narrow timeframes reinforce the need for fast absorption. The simpler a carb is, the quicker it will get to work.
Time of Absorption
During the ride, the rate at which you absorb carbs depends on the intensity. The higher the intensity of the work, the slower the absorption. But generally, simple sugars like glucose and fructose are taken up in 15-20 minutes.
Glucose and fructose are interesting because they use different pathways in the body. In simple terms, glucose is sent into the bloodstream, and fructose is sent to the liver to be converted to glucose. For a long time, the standard advice has been 60-90g of carbs per hour using a 2:1 glucose to fructose ratio. However, research is emerging that shows that upwards of 140g/hr can be absorbed using a 1:1 ratio.
What and When Should I Eat
Sports drinks and other products like gels are exceptionally effective for fueling during a ride. For events longer than an hour, a good starting point is 60-90 grams of carbs per hour. Try to ingest some carbs every 15 to 30 minutes. Before the start, you can consume a gel to stay on top of your nutrition. Just be careful to do this with less than 15 minutes to go, avoid a hypoglycemic rebound.
A word of caution; what and when to eat is highly subjective and varies significantly between athletes. This is something that you need to train and experiment during your training. Taking in more carbs than you can absorb leads to excessive gas and, eventually, diarrhea. Your tolerance for carbs during exercise is highly unique, so practice and take notes.
Carbs After Your Ride
After your event or workout is over, you’ll want to onboard carbs to replenish glycogen stores. That way, you can be ready to ride again. Depending on your situation, you can do this with recovery drinks and regular meals.
Time of Absorption
For about 30-40 minutes after, you can process carbohydrates and store glycogen at a high rate. This higher absorption rate trails off over time but stays elevated for about 48 hours. Additionally, the more glycogen depleted you are; the faster replenishment will occur. Adding some protein (3:1 carb to protein ratio) stimulates rapid glycogenesis as well as other recovery benefits like muscle repair.
What and When Should I Eat
Ideally, you’ll want to ingest some carbs as soon are you are finished. How you get them is flexible. A best-case scenario would be to finish your ride, then sit down to a nutrient-dense meal. In the real world, this is easier said than done. Typically, you can take in some drink mix or specific recovery drink to kickstart your refueling. Then when possible, sit down to a healthy meal.
With these tips, you can ensure that you have the fuel your body needs. Just remember, your body is unique. With training and experimentation over time, you can nail your nutrition.
For more cycling training knowledge, listen to Ask a Cycling Coach — the only podcast dedicated to making you a faster cyclist. New episodes are released weekly.
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Jesse, thanks for this great article. Could you please add more detail regarding the glucose:fructose part of the article?
“For a long time, the standard advice has been 60-90g of carbs per hour using a 2:1 glucose to fructose ratio. However, research is emerging that shows that upwards of 140g/hr can be absorbed using a 1:1 ratio”.
For example, if I am eating a Clif Bar, bread with jam, or most anything else for that matter, how do I know the ratio of glucose to fructose in that food item? I do not see this ratio on the food labels.
Thanks a lot,
Steve
Hi Steve,
Unfortunately, the standard US food label doesn’t help much when trying to find out what the ratios of sugar are in a product. Companies aren’t required to list the amounts of the ingredients they use. The good news is that some sports nutrition companies (like Science in Sport and Maurten do) publish that information for drink mixes and gels on their websites.
Thanks Jesse, that clarifies it!
Hi Jesse, I have a follow up question. The Maurten drink mix is very specific, mixing one serving with 500ml water, and instructions say to be exact when mixing. I often ride with 1 bottle of sports drink and 1 bottle of plain water. During a ride, is it advisable to drink ONLY one of these types of drinks until it is finished, then switch over to the other drink? In other words, if sipping back and forth between Maurten and plain water, does that adversely change the ratio and intended purpose of the sports drink? Thanks.
Hello TR,
As a TR user I’ve been listening to podcast no 244 and have been reading about ‘what and when to eat during a ride’. I found the insights by Chad very helpfull (thanks!) and have been searching the internet for a sportnutritionbrand that suppllies products complying these recommodations. That’s were I get lost.
Not all brands are clear about the 2:1 glucose to fructose ratio on productlabels (like gels).
Are there any brands who you guys recommend?
I would like to hear from you guys.
Kind regards,
Melle Plat – From Holland
Jonathan is a fan of Maurtens, but there are certainly other options out there if you do a bit of digging 🙂
Thanks!
hey TR
in your opinion, does it make any sense to target carbo intake intra-workout vs the TSS? E.G. Yday I’ve had Geiger+2, 104 TSS. My nutrition was as follows:
– 1hr before: energy bar 40g CHO
– during: 20 g CHO + electrolytes
– after: EEA + dinner/real food 80g CHO
How can I get a sense that this kind of intake is adequate and I’m not depleting reserves?
Hi, Stefano. Our recommendation is to look at the kilojoules expended during the workout instead of TSS. That will allow you to zero in on the caloric demands of each workout!
Thanks for replying. Looking at calories only doesn’t necessarily ensure you’re fuelling the right proportion of macros though. e.g. I can recover all calories burnt during a workout by just eating FATS and not rebuilding my carbs reserves. The aim was rather to have an objective parameter to be used for setting the right amount of carbs. On a day with a SweetSpot or Vo2max workout I can accept having a partial deficit in calories as long as over the week this balances off. I wouldn’t accept to create deficits in carbs instead.
Happy to expand upon that! Amber helped point us in the right direction here regarding that explanation:
In terms of fueling your training efforts, the actual number of kJs for a workout is a better metric for energy needs than TSS. You can estimate caloric needs for a workout based on kJs, which as a result of metabolic efficiency, can be understood as a 1:1 ratio (see for example trainerroad.com/blog/calories-and-power). A good rule of thumb is to make sure what you eat before and during your workout (in terms of CHO) equals the total kJ (kcal) you burn during the workout. You’re right that it’s important your nutrition includes all macros, but you can ensure your off-the-bike meals have plenty of protein and fats. In terms of performance, CHO will make the biggest difference to the quality of the workout, and toward recovering for the next day’s workout. It’s true we burn both CHO and fats during exercise, but for interval training, it’s mostly CHO. In terms of exogenous fuel, CHO is also far more easily and efficiently used to fuel your effort. To ensure you’re not depleting energy reserves, focus on CHO for before/during training (in addition to hydration of course), then on nutritional density/macros for other meals during the day. For this, look to kJs and kcal rather than TSS.
I can see your point. That’s feasible only for short indoor workouts though. e.g. yday I did 1 hour of sweet spot/threshold intervals and I’ve burnt 500 Kcal. If I had to assume the equivalent kcal in CHO that would’ve been 135 gr of maltodextrins over 90/120 minutes. Doable at home, albeit a bit close to the the boundaries of gastric tolerance, not outside.
I tried adding fructose to my regular maltodextrin mix (2:1 malto:fructose) in a 750ml bidon. While the malto drink alone is fine, adding the half-scoop of fructose made the drink too sweet. Is this something I just adapt to? or is there some other way of adding fructose that isn’t quite so nasty?
thanks for all the great work!
Hi, Ed! Good question, everyone is different and has a different ‘tolerance’ to sweetness and fructose additives. Maybe try a different brand of drink mix that has more fructose, but then getting fructose from a different source like gels, blocks, or even just candy so that you arent making your drink mixes so sweet! Cheers.