What Does Science Even Mean?
When Personal Experience Challenges the Consensus
As far as I can remember, since I was a kid, I never liked following the path that was dictated to me. I wanted to do things my own way, and in some areas—like school—it worked out quite well. But when I started cycling in secondary school, I knew I had some catching up to do compared to my peers, so I handed over the reins of my training to my coach(es).
Following the advice of older, more experienced people is comforting—you don't have to question whether the decisions being made are right for you. But it also means moving forward blindly, and in my case, it led to do silly things, like losing around 10 kilograms in about three months, at age 17, in an effort to climb faster.
The behaviors I developed during that period (a strong desire to overtrain and underfuel) forced me to acquire knowledge to dig myself out of the hole I was in. Not wanting to be fooled a second time, I turned to science and trusted people to help me discern what was true and what wasn’t. It was rough—I hated science in school—but slowly, I began to understand the principles I hadn't paid attention to in class.
A scientific method is an empirical one—meaning it’s based on observation or experience rather than theory. In fields such as nutrition or athletics, where conclusions can't be drawn from a single person’s experience, we often rely on scientific studies (or at least on those who can interpret them) to be more objective. Typically, they test an intervention on one group (the test group) and compare the results to another group who didn’t change anything (the control group). This helps provide a more accurate and unbiased view of how effective the intervention is.
The thing is, studies are built to validate or invalidate a hypothesis within the walls of a lab. But in the real world, external factors often come into play and affect the results.
Let’s look at the Low Carb High Fat (LCHF) versus High Carb Low Fat (HCLF) debate as an example:
Starting in the 70s or 80s, scientists in endurance sports started exploring whether a high-fat or high-carb diet better improved endurance performance. Since endurance events are mostly performed at submaximal intensities (fueled by fat stores), the idea was that training in a carb-restricted state would enhance fat oxidation, allowing athletes to go longer and faster without needing carbs (since fat stores are virtually unlimited).
...And that’s what they found! Athletes training in a carb-deprived state increased their fat oxidation. The “fasted training” concept quickly spread in the endurance world—only for researchers to realize, a few years later, that improved fat oxidation didn’t translate to better race-day performance. This shift in understanding has led to where we are today: carbohydrate intake is now seen as a competitive advantage. The winner isn’t necessarily the one who trained the most, but the one who can ingest the most carbs during the event.
My point isn’t to dismiss scientific evidence or claim that the studies were flawed. I just want to show that "real science" is complicated and constantly evolving. In Thinking, Fast and Slow, psychologist Daniel Kahneman explores major cognitive biases—one of the strongest being overconfidence.
He writes:
“Declarations of high confidence mainly tell you that an individual has constructed a coherent story in his mind, not necessarily that the story is true.”
While it might be frustrating to hear experts respond with “it depends” to questions about training or nutrition, it’s actually a sign of wisdom. The more expertise someone has, the fewer certainties they hold.
That said, you still need to hold on to some beliefs to move forward—otherwise you risk questioning everything, all the time. To stick with the topic of nutrition: given that I once restricted myself to the point of developing eating disorders, and that carbs are reportedly essential for endurance performance, I’ve always prioritized them in my diet. Science-based, right?
Still, I have to acknowledge a few things:
I frequently experience GI distress while running (which could be linked to my ED/RED-S history).
I struggle to feel “full,” even when consuming large amounts of carbs.
My bloodwork shows deficiencies, despite a diet supposedly tailored to my athletic needs.
I don’t think anyone should restrict a food group without a good reason, but I have to say that I stuck to the super high-carb approach long enough to say that it’s not all sunshine and rainbows. I think it's important to recognize that individual reality can sometimes fall outside the general consensus Studies focus on large populations and report results based on averages. But every study includes outliers—people who don’t respond like the majority. And they matter too.
I recently listened to an episode of the Training Science Podcast, hosted by Paul Laursen and Martin Buchheit—two respected sports scientists. The title struck me as both intriguing and potentially triggering for someone recovering from RED-S: A Man Fueling His Rides with ONLY Salt and Water.
I already knew of the guest, Sean Sako, an endurance cyclist. And since I’d heard plenty of content supporting high-carb diets over the years, I thought I’d give this one a listen. Sean shares his story about cycling, nutrition, and how the death of a loved one led him to adopt a ketogenic diet—for health reasons. Seeing someone close pass away from cancer, possibly linked to diet, made him reevaluate how he approached food and life. Today, he’s able to do long bike rides while staying in a ketogenic state, and apparently feels better than he ever did on a carb-rich diet. He and the hosts explored some of the potential scientific support for his approach—and who else might benefit from it.
I’m not saying I’ll go keto anytime soon, nor am I reversing my belief that carbs are usually beneficial for endurance athletes. But I think it’s crucial to stay open-minded and acknowledge that sports and nutrition science is evolving. It’s too early to claim that a high-carb approach is the only effective way to fuel endurance, or that it comes without any downsides. The only thing I’m sure of is this: no one should be blamed for seeking what’s best for their health and sharing their experience (with nuance) along the way. In my case, that episode sparked curiosity. It encouraged me to explore new ways of fueling (without restriction!) and to stop ignoring the downsides I was experiencing.
I hope my message came through clearly: I’m not saying that science or carbs are bad—at all. I just want to highlight that science isn’t clear-cut, and that it’s okay to ask questions and be skeptical of those who present easy answers.
Remember: if you give your mind the fuel it needs—nutrients, knowledge, movement—you’ll likely find what works for you.
Thank you for reading.
C