What the breakfast study actually tells cyclists

You’re getting ready for a long Sunday ride. You ate well yesterday, there’s breakfast on the table, and now you’ve seen a study suggesting that even a huge serving of carbohydrate barely changes what’s stored in your muscles and liver. It’s tempting to decide you can leave the food and get another hour in bed.

The finding deserves a closer look before you change the alarm.

Researchers at Maastricht studied 12 well-trained male cyclists, averaging 25 years old. They’d avoided strenuous exercise for two days, eaten their usual diet and had a standardised evening meal. After an overnight fast, they ate bread, jam and orange juice supplying 3 grams of carbohydrate per kilogram of body mass: about 219 grams on average. Then they rested for three hours.

Magnetic resonance measurements before and after breakfast found no significant increase in glycogen, the carbohydrate stored in the sampled thigh muscle or the liver.

The liver result is especially useful. Glycogen concentration rose by roughly 10%, but liver volume fell by about 6%. Once the researchers accounted for both, total liver glycogen was essentially unchanged: 53 grams before, 54 afterwards. Measuring concentration alone would have given a different impression.

But there’s a missing comparison. Nobody did the same morning without breakfast.

Liver glycogen can continue falling while you remain fasted. Breakfast may have helped maintain what was there. The authors raise that possibility themselves, but this study can’t measure the benefit against skipping the meal. Holding steady could still matter.

The muscles also started with high glycogen concentrations, which the authors interpreted as close to full. That makes the result much less surprising. It also leaves an obvious question unanswered: what happens when you arrive at breakfast after a hard training day with less carbohydrate stored?

And food has more than one route to being useful. Absorbed carbohydrate can be used for energy without first becoming a larger glycogen reserve. This experiment didn’t track where all the carbohydrate went, and nobody rode a performance test afterwards. We don’t know whether they would have ridden longer, harder or felt better. It certainly can’t tell someone who feels flat without breakfast that the problem is all in their head.

The useful correction is to the idea that a big breakfast automatically adds more stored fuel within a few hours. Turning that into advice to skip breakfast before a gran fondo goes well beyond what was measured.

What you do with this depends on which rider you are.

If you’re time-capped: keep your early-ride breakfast practical and familiar. You don’t need to copy a 219-gram laboratory meal, and this result gives you no reason to abandon food that helps you complete your key session.

If you’re over 50: these were young men, so there’s no age-specific breakfast rule here. Keep a routine you tolerate and judge it against the work you can do, rather than changing it because one glycogen measurement stayed level.

If you’re chasing a result, or it’s a new event for you: plan the previous day’s food, breakfast and on-bike fuelling together. Rehearse that sequence on a comparable training ride. This study didn’t test whether gels during a race can replace breakfast, either.

Prepare your fuel across the whole day. Don’t let one morning measurement make the whole decision.

Source. Fuchs CJ, Veeraiah P, Hermans WJH, et al. Breakfast consumption does not rapidly increase liver or muscle glycogen content in well-trained cyclists. American Journal of Physiology–Endocrinology and Metabolism. 2025;329:E774–E780. doi:10.1152/ajpendo.00400.2025.

On my mindThe conversation we owe our athletes

When an athlete falls short of a goal, I want to understand why. What didn’t work? What did we miss? What could we do better next time?

Sometimes that means raising something uncomfortable.

An athlete might have a big cycling goal while also doing another sport they love. There may be a point where taking a break from that sport would give the cycling preparation a better chance. As a coach, I owe them that conversation, even if I’m fairly sure they’ll say no.

They might have a very good reason to keep doing both. The choice belongs to them. My responsibility is to explain the trade-off clearly enough that it’s a real choice.

It’s easy to avoid the subject because you don’t want to push too hard or spoil something they enjoy. But staying quiet can leave both of you wondering afterwards whether there was an option you never properly considered.

I want an athlete on the start line knowing what they chose, why they chose it, and that we did everything we could within those choices. I want to know I did my part, too.

Before the next big block, name the conversation you’ve been putting off. Have it while there’s still time to act on the answer.

— Damian

PS. If you want a plan and regular feedback through winter, The Winter Block starts on 2 November. Sixteen weeks of structured training for riders 40+, indoors or outdoors, with weekly key-session feedback and a small group to train alongside. See The Winter Block →

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