120 grams per hour. What it actually means.

Listen to this issue as a podcast

A new review from Morton and colleagues in the Journal of Nutrition centres on the "crossover point," the moment during sustained exercise where carbohydrate stops being your predominant fuel source and your body shifts toward burning more fat. In practice, that means lower power output and less capacity to respond when the race demands it.

Here's what the review reports: with zero carb intake, that crossover happens at roughly two hours. At 45 to 90 grams per hour, it's delayed by 30 to 60 minutes. At 120 grams per hour and above, the crossover doesn't appear to occur at all.

That 120-gram finding is the headline. But before we run with it: most of this research comes from young, well-trained male athletes in controlled lab conditions. The direct applicability to a 48-year-old riding a sportive isn't automatic. Gut tolerance is a real limiter. Plenty of riders who jump to high intake rates end up with GI distress that costs them more than the extra carbs would have saved.

The headline number needs a coaching filter before it becomes a personal fuelling plan.

What to do with this

If you race or do hard rides over 2.5 hours: If you're at 60 grams per hour, push higher. But do it gradually. Start practising 70 to 80 in training before chasing 120 on race day.

If you do big endurance rides (4+ hours): You don't need 120, but you do need to eat consistently and early. A steady 60 to 80 grams per hour from the start will do more for your last two hours than a heroic intake you can't absorb.

If you're a masters rider: Be cautious about the "more is better" train. GI tolerance and absorption rates can shift with age. Start conservative, practise in training, find your own ceiling.

Morton et al. (2026). From Metabolism to Medals. Journal of Nutrition, 156(5), 101442.

On my mindWhen the schedule clears, don't waste it

The weeks that go to plan are rare. Something always comes up. The unexpected is basically the expected at this point.

So when you do get a clear week, that's not a normal week. That's an opportunity. I don't mean smash yourself. I mean use that space to tighten something up. Nail your fuelling on the long ride. Do the strength session you've been skipping. Go to bed earlier and see what that does to your Thursday intervals.

Most riders treat a good week as a chance to add volume. The riders who improve fastest do something different. They raise the quality of what's already there, not pile more on top.

The busy weeks will come back. So when the window opens, don't just ride more. Tighten something up.

Damian