Why Nutrition Comes First

Joseph Marcavage • July 5, 2026

Why Nutrition Comes First

Eat meat and vegetables, nuts and seeds, some fruit, little starch, and no sugar. Keep intake to levels that will support exercise but not body fat.

Those are the opening words of CrossFit's famous Fitness in 100 Words, and they are no accident. Before strength, gymnastics, weightlifting, or conditioning, CrossFit places nutrition at the foundation of fitness. The Theoretical Hierarchy of Development illustrates this perfectly: every level of athletic performance is built upon the quality of what we eat. If the foundation is weak, everything above it becomes harder to develop and sustain.

CrossFit's Theoretical Hierarchy of Development, Nutrition is the Foundation

Hormones and Energy

Nutrition affects far more than the number on the scale. Every meal influences hormones like insulin and glucagon, which work together to regulate blood sugar and determine whether your body stores it or uses it immediately for fuel. When we consistently choose whole, nutrient-dense foods, these systems function as intended ("homeostasis") providing steady energy, improved recovery, and better performance. Poor food choices, however, can keep insulin elevated for prolonged periods, making it increasingly difficult for the body to efficiently access stored fat. Think of it like this, with constantly elevated insulin levels, your body is saying, "hey, we've got incoming energy (food you ate), so let's use that for energy first". Your body just doesn't have time to get back to a state of using stored fat for general processes (breathing, beating your heart, energy to stay focused at work, doing the dishes, etc.).

Insulin Resistance

Over time, consistently poor nutrition can contribute to insulin resistance, a condition in which the body's cells become less responsive to insulin and sugar stays in the blood stream. The effects extend well beyond weight gain. Many people experience chronic inflammation, low energy, brain fog, disrupted sleep, acne, slower recovery, and persistent cravings without realizing that nutrition may be the underlying cause. If your body stays under these conditions long enough, it can lead to a struggling pancreas, elevated blood sugar levels, Prediabetes, and Type 2 Diabetes. In summary, while exercise is a powerful tool for improving health, it is difficult to out-train a diet built on highly processed foods and excessive sugar.

Follow CrossFit's Prescription

Nutrition is one of the greatest investments you can make in your health and performance. Whether your goal is to lose body fat, build strength, improve your healthspan, or to prepare yourself for the unknown and unknowable, it all begins with a solid nutritional foundation. Build the base first, and everything above it becomes stronger.

I'm Coach Joe Marcavage. I've owned CrossFit Vertex since it opened in 2012 and I've been working on my own health and fitness for over 30 years. I'd love to meet up to discuss how CrossFit Vertex can help you achieve your health and fitness goals. Joe's Schedule.

Joe Marcavage

Owner, CrossFit Vertex