This is a first-person opinion piece. I'm an age-group triathlete and co-founder of AiTrainingPlan. I tested this myself, on my own rides, without a team nutritionist handing me product at kilometer markers. The numbers are real. The failures are real. The opinions are mine.
By Thomas Prommer · Updated April 2026
90 g/hr is the practical ceiling for most age-groupers. I tested 90, 105, and 120 over six long rides. 90 worked clean. 120 broke down at 2.5 hours with GI distress and gel-logistics failure. Pro protocols assume support infrastructure age-groupers don't have. The gap between where most of us fuel and where we could fuel is real — it's just 90g, not 120g.
The Scene That Started This
Earlier this year, a post from Jonas Vingegaard's nutrition team started circulating in the cycling communities I follow. The detail that lodged in my brain: the team was routinely hitting 120 grams of carbohydrate per hour on long Tour stages. Not as a ceiling. As a target.
Within 48 hours, a Slack channel I'm in had three separate threads about Vingegaard's plan, and predictably a wave of recreational athletes was concluding they should immediately double their gel intake on Saturday's long ride.
I've been in endurance sports long enough to know what usually happens next. Someone reads a protocol designed for a rider with a team dietitian, a soigneur handing up custom bottles every 20 minutes, and years of deliberate gut adaptation. And tries to replicate it alone on a 4-hour ride with gels stuffed in their jersey pocket. The resulting GI disaster gets filed under "high carb fueling doesn't work for me."
So I did what any sensible obsessive would do. I read the research, then I tested it myself, across six rides over six weeks, at three intake levels. This is what I found.
What the Pros Are Actually Doing
The 120g/hr number isn't new. Research from Jeukendrup's lab at Loughborough was showing trained athletes could oxidize above 90g/hr as far back as 2004, using mixed carb sources. What's changed is the infrastructure around it.
Vingegaard's Visma-Lease a Bike team partners with Neversecond, whose C30 gels (30g per sachet) are designed specifically to stack. Four gels per hour, 120g. Precise, consistent, tested during training over months. Their in-race support means bottles are handed at regular intervals with pre-calculated carb content. Nothing is improvised.
Tadej Pogacar's UAE Team Emirates setup is similar in ambition: high carb targets, race-day nutrition planned by sports scientists who know exactly what he ate at breakfast, what his sweat rate is on that specific climb, and how his gut responds under race stress. Maurten's hydrogel technology was developed partly in collaboration with this level of elite demand, with Kipchoge's team also in the mix.
Jakob Ingebrigtsen's approach is interesting because it crosses into running, where the GI environment is considerably more hostile than cycling. His team's collaboration with Dr. Asker Jeukendrup (now working with Neversecond) focuses on gut training as a systematic process, not a race-day choice but a daily training variable over months. The numbers they're targeting during hard track sessions were reported to be well above 60g/hr.
The common thread: none of these athletes arrived at 120g/hr overnight. They trained their guts methodically, with professional support, over extended periods. And they race in conditions where execution logistics are handled by a team.
Why 120g/hr Is Possible Now
My read of Jeukendrup's newer work and the underlying physiology: it requires understanding two transport systems.
Glucose is absorbed via SGLT1 transporters in the small intestine. These saturate at roughly 60g/hr. For decades that was treated as the ceiling. Then researchers noticed that fructose uses a completely different transporter, GLUT5, which operates independently. If you provide carbs in the right glucose-fructose ratio, you're running two absorption pathways simultaneously rather than one.
The optimal ratio for maximizing oxidation is approximately 2:1 glucose to fructose, or roughly 1:0.8 if you're going by maltodextrin-to-fructose numbers. At 90g/hr that means about 60g from glucose sources and 30g from fructose. At 120g/hr, it's 80g glucose and 40g fructose, give or take. Products that don't hit this ratio simply cannot deliver high carb rates without creating an osmotic backlog in the gut that eventually results in the kind of bathroom emergency that ends rides.
Maurten's hydrogel technology takes this further. The idea is that encapsulating the carbs in a gel matrix (formed by alginate and pectin reacting with stomach acid) slows gastric emptying in a controlled way, reducing osmotic stress in the small intestine. The research on whether hydrogel actually outperforms conventional high-carb mixes is still contested. The 2020 BJSM paper from Glasgow Caledonian showed advantages in GI comfort, though the performance delta was modest. What's clear is that many elite athletes feel more comfortable on Maurten at high doses, which is its own form of evidence.
Then there's gut training. Jeukendrup's group showed that consistent exposure to high carb intake during training upregulates SGLT1 expression and increases the gut's fructose oxidation capacity over 4-6 weeks. The intestine adapts. Not in one ride. Across a training block of regular practice.
My Experiment: Six Long Rides at 90, 105, and 120g/hr
I'm an age-group triathlete, training for Challenge Roth (full Ironman, July 2026). My long rides run 3.5-4.5 hours. I had been fueling at around 70-80g/hr for months, using a combination of gels and bottles. Comfortable, consistent, no GI issues.
The protocol: two rides at each level, with a week between each tier to allow gut recovery and assess the pattern. Same route, same rough intensity (zone 2 with 15-20 minutes of threshold work midway), same morning nutrition before the ride. I tracked everything in my athlete tracking system: power, heart rate, perceived exertion, and GI symptoms rated 1-5 at each hour.
Products used:
- Maurten Drink Mix 320 (80g carbs per 500ml, 0.8:1 glucose-fructose ratio)
- Neversecond C30 gels (30g each)
- Styrkr MIX 90 for one ride at the 105g tier
90g/hr — Rides 1 and 2
One bottle of Maurten 320 (80g) plus one C30 gel (30g) over 60 minutes, targeting 90g, landing somewhere around 85-90g depending on how aggressively I drank. Both rides: GI symptoms rated 1/5. No bloating, no stomach turning, no regrets at the turnaround. Power was good on the threshold section. The 4-hour ride finished clean.
This is probably where I should have stopped the experiment and called it a day, because this is the outcome I wanted: more fuel in, same GI comfort. But I kept going.
105g/hr — Rides 3 and 4
One Maurten 320 bottle (80g) plus two C30 gels (60g) divided across the hour, targeting 105-110g. Ride 3: manageable. Some bloating in hour 2, resolved by hour 3. GI rating: 2/5 for about 40 minutes. Ride 4 with Styrkr MIX 90: heavier stomach feel from the start, more consistent 3/5 GI noise across hours 2-3, nothing that forced me to slow down or stop, but present enough that I was thinking about it during the threshold interval instead of focusing on the effort.
Power output looked the same in the data. The glycogen feel at hour 4 was noticeably better than my baseline 75g/hr rides. So the fuel was getting in. My gut just wanted me to know it wasn't thrilled about the quantity.
120g/hr — Rides 5 and 6
This is where things got honest.
Ride 5: I hit 115g in the first hour (ran out of one gel earlier than planned), then pushed to 120g in hour 2. By hour 2.5 I was dealing with a 4/5 GI situation. Not "pull over" bad. Bad enough that I backed off to zone 1, sipped water, and dropped intake to zero for 25 minutes while my gut caught up. Power cratered. The threshold interval at the midpoint was laughable. I soft-pedaled through it rather than push into a GI event at 45 km from home.
Ride 6 went better because I was more deliberate about spreading intake and drinking enough water to prevent concentration buildup. GI rating: 3/5 sustained across hours 2-3. I got through it without stopping. But the cognitive overhead was significant: constant monitoring of how my stomach felt, adjusting gel timing, managing hydration against intake. During Ironman racing, that cognitive bandwidth is already occupied by pacing, position, wind, other riders. I can't also be running a real-time gut health assessment every 15 minutes.
Also: carrying the product is harder than it sounds. To reliably hit 120g/hr for 5-6 Ironman bike hours with multiple gel flavors (flavor fatigue at hour 3 is very real), you are bringing 25-30 gels plus several bottles of mix. The jersey pocket logistics alone are a training project.
What Actually Broke at 120g/hr
Let me be specific, because vague claims about "GI distress" don't help anyone plan their fueling.
Bloating in hour 2, every time. The carbs that don't clear the stomach fast enough start fermenting. You feel it as pressure and sloshing. At 90g/hr this window is short. At 120g/hr it lasted 40-60 minutes on my better rides and didn't really resolve on the bad ones.
Flavor fatigue by hour 3. Even rotating between two products, the sweetness became actively aversive around 3 hours. I started avoiding gels I had planned to take. Which means my actual intake dropped below target, defeating the whole exercise.
The single-point-of-failure problem. At 75g/hr, if I miss a gel or a bottle runs out early, I'm slightly undertargeting for 20 minutes. No real consequence. At 120g/hr, missing one product unit in an hour means I'm at 90g, still fine. But the logistics of maintaining that intake precisely for 5-6 hours creates constant small failure opportunities: a dropped gel, a bottle cage that doesn't seat cleanly, a flavour I can't force down. Each one costs me maybe 15-30g of planned intake. Those add up.
Gut adaptation debt. I had been at 70-80g/hr for months before this experiment. Six weeks is not enough gut training to go to 120g comfortably. Jeukendrup's research suggests 4-6 weeks of consistent practice at a target level before it feels routine. I was essentially ramping too fast and paying the price.
The 90g/hr Sweet Spot
Here's the frustrating truth: 90g/hr worked so well it almost made me angry about the weeks I spent at lower intake levels.
Coming from 70-80g/hr, jumping to 90g felt like turning on a light. Hour 3 on long rides stopped feeling like a negotiation with my legs. The glycogen feel at hour 4 was different. Not the subtle increasing heaviness I was used to, but something flatter, more sustained. I finished rides with more left.
And it's executable. One Maurten 320 bottle (80g) plus one C30 gel (30g) per hour is manageable in terms of product volume, easy to carry, and the flavour doesn't destroy me at hour 3 because the Maurten is fairly neutral. GI symptoms stayed at 1/5 across both rides. I could run a threshold interval without thinking about my stomach.
For the Ironman bike leg at Challenge Roth, I'm targeting 85-90g/hr for the first 4 hours, with the option to push to 95-100g in the final 60 minutes if I'm feeling strong. That's the plan. Not 120g. Not because 120g is impossible, but because 90g is reliable, and reliability is what actually matters in a race you've been training for 18 months.
For reference specs and per-product carb calculations, AiTrainingPlan has a detailed carbs per hour reference page covering different sports, body weights, and intake targets.
When 120g Might Be Worth It
I don't want to be the guy who tested something insufficiently and declared it doesn't work. There are scenarios where 120g/hr makes sense for age-groupers, and I want to be honest about those.
The final 90 minutes of an Ironman bike leg. If you've been at 85-90g/hr for hours 1-4.5 and your gut is warm, experienced, and handling it, pushing to 100-110g in the final stretch before T2 is a legitimate strategy. You're not asking your gut to adapt from cold since you're pushing an already-running system. The Ironman run is going to hurt regardless; you might as well arrive at T2 with maximal glycogen stores.
After 4-6 weeks of true gut training at 100g+. If you actually do the work, hitting a high target in every long ride for 6 weeks, not just one ambitious session, your baseline will shift. Some people tolerate 120g comfortably after that process. I didn't have the time to find out properly within my experiment window.
Truly sub-threshold intensity for 2-3 hours. Lower-intensity rides create a friendlier GI environment because blood flow isn't being aggressively rerouted from the gut to working muscle. If you're doing a long slow base ride and not pushing intensity, 120g/hr is more feasible. The practical relevance here is low for most age-groupers' race contexts, but it's a valid training scenario.
On the bike, not the run. Cycling posture is GI-friendly compared to running. The jostling, the compressed-core mechanics, the bouncing: running multiplies every GI issue. 120g/hr on the bike in ideal conditions. 70-80g/hr running in a triathlon is already ambitious. The research Ingebrigtsen's team is doing in running is genuinely impressive, but they're not starting from scratch and they're not working alone.
How to Actually Practice It
If you want to get to 100g/hr or above, here's the protocol that reflects both Jeukendrup's published research and what actually worked for me:
- Find your current comfortable ceiling. If you've been fueling at 60g/hr and have no GI issues, start there. If you're already at 80g, start there. Don't leapfrog.
- Fix your carb ratio first. If you're using products with pure maltodextrin or pure glucose, you're already capped. Switch to dual-source products (Maurten, Neversecond, Styrkr) before increasing volume.
- Add 10-15g/hr every 2-3 weeks, in training only. Gut training only works if you do it consistently, not just on big days. Every long ride, hit the target. Your gut needs repetition to adapt, not one heroic session.
- Drink enough water. High carb concentration in the gut creates osmotic stress. More carbs means more fluid needed to keep gastric emptying on track. I was drinking roughly 750ml/hr at 90g and needed to push closer to 900ml at 105g.
- Keep race-day nutrition conservative until you've genuinely adapted. The worst place to test a new intake level is a race you've been training for six months. Train high, race at a level you've proven you can execute without incident.
- Log every session. You need to know whether week 4 at 100g/hr feels better than week 2, or whether your symptoms are flat-lining and you need to back off and let the gut catch up. Without data you're guessing.
Jeukendrup's full review of carbohydrate recommendations is published in Sports Medicine (2011) and updated in the MySportScience blog if you want the mechanistic detail on SGLT1 and GLUT5 transport capacity.
The Verdict
120g/hr works. The science is solid. The elite athletes doing it are doing it for real, not as a marketing exercise.
But there's a gap between "120g/hr works for Vingegaard during a Tour de France stage with a team of eight people supporting his nutrition" and "120g/hr is what you should aim for on Saturday's long ride based on something you read on Reddit."
I'm not Vingegaard. You're probably not either. The translation from pro to age-group isn't zero, but it requires honest answers to some uncomfortable questions: Have you spent 6 weeks gut training at progressively higher intakes? Are your products actually dual-source with the right ratio? Can you carry and execute 25 gels and 4 bottles of mix cleanly for 5 hours while also pacing, drafting, and managing a race?
My practical recommendation: get to 90g/hr with reliable execution before you chase 120g. Nail the basics. Train your gut systematically. Then push the ceiling if you have a specific reason to and the time to do it properly.
The arms race is real. The 30g/hr gap between where most age-groupers are fueling and where they could be fueling is worth chasing. Closing that gap costs less than a pair of aero socks. But start at 90, not 120. Close the low-hanging gap first, and don't let the pro protocols make you skip the steps that actually get you there.
If you're thinking about how this connects to body composition and weight management during heavy training, my GLP-1 journey article covers the fuel-appetite interaction in detail: GLP-1 for Athletes: My Journey to Race Weight.
Frequently Asked Questions
Is 120g of carbs per hour realistic for amateur athletes?
For most age-group athletes, 120g/hr is technically possible but logistically difficult and GI-risky without months of dedicated gut training. Precision Hydration's research shows trained athletes can exceed 90g/hr, but the practical ceiling for most amateurs without a team soignée handing them product is lower than for pros. I found 90-105g/hr was the realistic ceiling for consistent execution on self-supported rides.
What carb ratio is needed for 120g/hr?
You need a glucose-to-fructose ratio of approximately 1:0.8 (roughly 2:1 glucose to fructose) to use multiple intestinal transporters simultaneously. At 120g/hr, glucose transporters (SGLT1) saturate around 60g/hr, so all additional carbs must come via fructose through GLUT5 transporters. Products like Maurten (0.8:1 ratio) and Styrkr (2:1 ratio) are formulated specifically for this. Standard gels with pure maltodextrin hit a ceiling at 60g/hr regardless of dose.
What did Jakob Ingebrigtsen eat for carbs during training?
Ingebrigtsen's team (working with Dr. Asker Jeukendrup and Neversecond) reported carb intakes during hard training sessions well above the old 60g/hr ceiling, citing gut adaptation protocols. The specific numbers aren't publicly disclosed, but the approach aligns with the general move in elite running toward higher fueling rates during quality sessions, not just races.
How do you train your gut to absorb more carbs?
Dr. Asker Jeukendrup's gut training research shows the intestine adapts like a muscle: regular exposure to high carb intake during training gradually upregulates SGLT1 transporter expression and increases fructose oxidation. The protocol is straightforward: pick a carb target, hit it consistently in training (not just races), start at a manageable level and increase by 10-15g/hr every 2-3 weeks. Takes 4-6 weeks to see meaningful adaptation.
What products work at 90g/hr or above?
You need products with optimized glucose-fructose ratios. Maurten Drink Mix 320 (80g carbs, 0.8:1 ratio) is the most widely used at high doses. Styrkr MIX 90 delivers 90g per serving with 2:1 ratio. Neversecond C30 gels (30g each, used by Jumbo-Visma/Visma-Lease a Bike) stack cleanly. Carbs Fuel's 80g drink mix is the budget option. For solid fuel, the Styrkr SF 90 bar at 90g is an interesting approach for longer low-intensity sections.
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