Age-group triathletes are some of the most motivated amateur athletes in the world - when it comes to training. Diet is a different story. Coming from the weightlifting world, where even hobbyists tend to have their nutrition dialled in, the gap in endurance sport is striking.
The Two Camps Most Triathletes Fall Into
Most amateur triathletes sit in one of two categories. The first group eats extremely clean and healthy but does not eat enough. The second group eats enough total calories but with poor nutritional quality.
Here is the uncomfortable truth: the second group will almost always outperform the first. Calories are the basis of energy production. If you do not have enough fuel, you are going nowhere - and you risk under-recovering from your training - regardless of how clean your diet looks on paper.
A Simple Nutrition Framework That Works
The approach is straightforward: cover your foundational nutritional requirements first, then backfill calories as needed.
That is it. No complicated meal plans, no restrictive diets, no guilt about food choices. Just two steps done consistently.
Step One: Cover Your Foundations
Protein first. Ensure you are getting at least 1.5 to 2 grams per kilogram of body weight per day. This is non-negotiable for recovery and adaptation. Most endurance athletes chronically under-eat protein, which can contribute to hormonal disruption and overtraining symptoms.
Then address your micronutrients. The easiest way to do this is to log your food in an app like Cronometer, which will show you exactly where your diet is falling short. From there, add foods that fill those gaps. Cronometer will even suggest which foods are rich in the nutrients you are lacking.
If there are still gaps after adjusting your diet, supplement the remaining micronutrients. But food first, supplements second.
Step Two: Backfill Your Calories
Once your protein and micronutrients are covered, fill in the remaining calories however you need to meet your energy demands. This is where flexibility matters more than perfection.
Some days that might be beef mince and basmati rice. Other days, after a big training session, it might be fast food - because hyper-palatable, calorie-dense meals are sometimes the most practical way to meet your energy needs after a four-hour ride.
The point is not to eat junk all the time. The point is that once your nutritional foundations are covered, the source of your remaining calories matters far less than most athletes think.
Cover your foundations first. Then eat enough to support your training. It really is that simple.
Where to Learn More
If you want to dive deeper into this approach, look into Stan Efferding and his Vertical Diet. It is technically a paid resource, but there is a significant amount of free content online covering the core principles. The framework aligns well with what endurance athletes need - high-quality nutrition with enough total energy to support serious training loads.