Does Carbohydrate Type Really Matter? Fixing the Two Things That Matter More

Spend ten minutes in any endurance forum and you will find an argument about carbohydrate type. Maltodextrin versus glucose versus fructose versus "real" sugar, with everyone certain that their pick is the secret. So does carbohydrate type matter? Yes, but far less than most people think, and only once you have sorted out two bigger issues first.

Most athletes who bonk, cramp up or end up grey-faced in the portaloo do not have a carbohydrate type problem. They have a dose problem or a gut problem. Get those right and the type becomes a fine-tuning decision. Get them wrong and no clever ingredient list will save your race.

What Carbohydrate Type Actually Changes

Different sugars use different doors to get from your gut into your blood. Glucose (and the glucose chains in maltodextrin) is absorbed mainly through a transporter called SGLT1, which tops out at roughly 60g per hour. Fructose uses a separate transporter, GLUT5. Because the two routes do not compete, taking both lets you absorb more carbohydrate per hour than glucose alone can manage.

That is the real reason carbohydrate type matters. Research on multiple transportable carbohydrates has shown that a glucose and fructose blend can support intakes of 90g per hour and above, with higher rates of exogenous carbohydrate oxidation than glucose alone. A 1:0.8 to 1:1 glucose to fructose ratio is the common recommendation for that bracket.

Below about 60g per hour, though, the argument largely falls away. If you are sipping 40g an hour on a steady two-hour run, a single carbohydrate source will do the job and your gut will not know the difference. Type only becomes decisive when you push past the single-transporter ceiling.

The First Thing That Matters More: Total Dose

The biggest performance lever in fuelling is how much carbohydrate actually goes in per hour. A rough guide:

• Under 60 minutes: little or nothing needed, a mouth rinse at most.
• 1 to 2.5 hours: 30 to 60g per hour.
• Over 2.5 hours: 60 to 90g per hour, with the higher end only if you have trained for it.

I see athletes obsess over the sugar blend in a gel and then eat 30g an hour on a five-hour ride. The ingredient list is irrelevant when the quantity is half of what the session demands. Write down what you really consume in your next long session. Count the grams, not the products. Most people discover they are well short.

Timing matters as much as the total. Small, regular intakes every 15 to 20 minutes keep blood glucose steady and are easier on the stomach than a big hit once an hour. Set a watch alarm and treat eating as part of the session, not an afterthought.

The Second Thing That Matters More: Gut Training

Your gut adapts to carbohydrate in much the same way your legs adapt to hills. If you only ever eat 30g an hour in training and then try 90g on race day, expect trouble: bloating, cramps and sometimes worse. Studies on gut training suggest that repeatedly practising high carbohydrate intakes can improve tolerance and absorption over a couple of weeks.

A simple approach is to raise your intake by 10g per hour every week or two on your long sessions until you reach your target. Keep fluid intake sensible and avoid high-fibre, high-fat food in the hours before. If something upsets you, drop back a step rather than abandoning the plan.

This is also why unfamiliar race-day products are a gamble. A fuel that sits well in a 90-minute test might behave differently at hour four when you are dehydrated and tired. Rehearse your exact plan, in the same conditions, more than once.

A Worked Example: Five Hours in the Saddle

Say you are riding a five-hour sportive and want to take in 75g of carbohydrate per hour. That is 375g across the day, or roughly one carbohydrate unit every 15 minutes if you break it into 18 to 19g portions. Use a timer, eat on the timer, and do not wait until you feel hungry, because by then you are already behind. Wait until the second hour to judge how your stomach is coping and adjust from there, rather than panicking in the first twenty minutes.

Add fluid at roughly 500 to 750ml per hour depending on heat and sweat rate, plus sodium if you are a heavy sweater. Concentrated carbohydrate drunk with too little water is another common route to a sloshing, uncomfortable stomach, and it is entirely unrelated to the type of sugar involved. Sort the plumbing before you blame the ingredients.

Keep a simple log after every long session: grams per hour, how your stomach felt, and how the final hour went. After four or five entries the pattern is usually obvious, and it tells you far more than any ingredient debate ever will.

So When Should You Care About Carbohydrate Type?

Once you have the dose dialled and your gut trained, type becomes worth a look in three situations. First, if you are aiming above 60g per hour, choose a glucose and fructose blend rather than a single sugar. Second, if you have a sensitive stomach, check that the fructose content is not too high, since excess fructose without enough glucose is a classic cause of GI distress. Third, if you struggle with sweetness or flavour fatigue late in an event, variety and format matter more than the molecule.

It is also worth noting that "natural" does not automatically mean better. Honey, dates and fruit juice are perfectly good fuel, but their glucose to fructose ratios are unpredictable, so they are harder to dose precisely. Predictability is the main attraction of a formulated product.

What We Use at FTP Endurance Fuel

We built our energy pastilles around exactly this thinking. Each one delivers a measured glucose and fructose blend, so you can count carbohydrate in simple units and hit 60g or 90g an hour without guesswork. They are firm, easy to portion and easy to eat on the move, which makes the regular small intakes much less of a chore than fumbling with sticky sachets.

If you are new to the format, the Taster Pack is a low-risk way to test them in training before you commit. For bigger weeks and race prep, the Mixed Fruit Pastilles 1kg bag gives you plenty of runway to practise your plan.

The takeaway is simple. Stop agonising over whether your carbohydrate is maltodextrin, glucose or fructose until you have nailed your hourly grams and trained your gut to cope with them. Then pick a sensible blend and stick with it. Ready to put it into practice? Start with the bundles and build a fuelling plan you can trust on race day.