Back in 2023 I wrote two blogs on the 120 grams per hour question. The conclusion both times was the same. The evidence did not support it, the extra carbohydrate was not sparing glycogen, and for most triathletes it was not worth the gut risk.

That position has not changed. What has changed is the question.

Because the athletes at the front keep doing it. Aggressive fuelling has become standard across marathon, professional cycling and long course triathlon, and it has been associated with a run of record breaking performances. Worth being precise about that word. Associated. The trend is supported largely by anecdotal reports rather than by evidence, and nobody has shown these intakes caused those results. But it leaves two possibilities. Either those athletes are winning despite their nutrition strategy, or something is happening that our current models do not capture.

That is what we set out to explore in a new Current Opinion paper in Sports Medicine, written with Paul Booth, T...

It’s not what you can do for 5 minutes, it’s what you can do for 5 minutes after five hours. As endurance athletes, we know that our endurance – our physiological and psychological ability to endure, to keep going as the hours tick up in our event – is fundamental to our performance.

‘Durability’ is an emerging concept in exercise physiology, and, more importantly, we think, a critical factor in endurance training and performance. In our 2021 paper, we defined durability as an athlete’s resilience to the effects of prolonged exercise on their physiological profiling characteristics – the thresholds we use to inform pacing strategies, programme training sessions, and monitor training load (1). Subsequently, durability has been proposed as a crucial factor in endurance performance, as it defines, physiologically at least, our ability to stave off the upward creep in effort required at a given speed or power output as exercise progresses (2). As readers of our blogs, or our monthly Train...

I wrote a blog about the recent research assessing the effects of ingesting carbohydrates at very high rates, >120 grams per hour, during endurance exercise (1, 2). My view of the literature, as discussed in the blog, is that there isn’t yet any compelling evidence that ingesting carbohydrates at these super high rates will improve long-distance triathlon performance, or that it’s worth the logistical hassle and risk of gastrointestinal upset. Indeed, there’s even some evidence that carbohydrate ingestion at rates above 90 grams per hour accelerates muscle glycogen depletion and impairs performance (3, 4).

In this blog, inspired by an engaging Twitter thread authored by Prof. Tim Noakes and Iñigo San Millán, I'll delve into the metabolic outcome of ingesting 120 grams of carbohydrates per hour. Through this exploration, I aim to reinforce the perspective that such elevated carbohydrate intake rates might not justify the risk for Ironman triathletes.

Peak ...