Food Composition for Spartathlon Ultramarathon Runners

At Saturday, our aim is on heightening athletic performance through a strategic refinement of nutrition. An integral part of this refinement involves an in-depth comprehension of food composition, encompassing elements such as digestibility, bioavailability, and the levels of essential nutrients. While food composition may not be the pivotal instigator of athletic performance, it plays a substantial role in setting an ultrarunner's nutritional landscape and metabolic efficiency.

Proteins: Evaluating Quality and Digestibility

A close examination of proteins involves focusing on their quality and digestibility. The standard of a protein is primarily gauged by the mix and ratios of amino acids it possesses. Of the 20 amino acids, 11 are produced internally (non-essential), while the other 9 (essential) need to be provided through dietary means. Proteins are categorized as either complete or incomplete, based on the presence or absence of all essential amino acids. Nevertheless, the strategic combination of several incomplete proteins can lead to a comprehensive protein that adequately meets the essential amino acid demand. Foods such as poultry, venison, and seafood are examples of complete proteins delivering all essential amino acids. On the other hand, lentils and grains are incomplete proteins, but when combined, they can provide a comprehensive amino acid profile.

Digestibility of a protein, which indicates the amount of ingested protein absorbed and used by the body, is another key consideration. The Protein Digestibility Corrected Amino Acid Score (PDCAAS) offers an authoritative evaluation of protein digestibility, scored on a scale from 0 to 1.0. Animal-based products usually achieve high PDCAAS scores, reflecting excellent digestibility and quality. In contrast, plant-derived proteins exhibit lesser digestibility, primarily due to cellulose—an indigestible component of plant cells—that hinders total protein uptake. In light of these observations, we advocate for a considerable share of protein to come from animal-based foods due to their superior quality and digestibility.

Carbohydrates: Grasping Digestion Speed and Nutrient Density

The quality of carbohydrates relies on two factors: digestion rate and nutrient density. The Glycemic Index (GI), a scale from 0 (lowest) to 100 (highest), acts as a reference point. It measures the digestion pace and absorption of carbohydrates into the bloodstream, with fast-digesting sources leading to a speedy spike in blood sugar and hence higher GI values. Conversely, slow-digesting sources lead to a more measured increase, yielding lower GI values.

The GI is important for both health and athletic performance. Lower GI carbohydrates, like whole grains and legumes, typically offer additional health benefits such as fiber, micronutrients, and phytochemicals. Conversely, for athletic performance, consuming high-GI carbohydrates, like glucose, during exercise assures a rapid supply of glucose to the bloodstream while minimizing gastrointestinal issues. The GI of your carbohydrate intake can be influenced by several factors, but a useful guideline is that the further from exercise you are, the lower the GI of your carbohydrate should be.

Fats: Classifying the Types

Fat quality is primarily determined by its category: monounsaturated, polyunsaturated (including omega-3 and omega-6), saturated, and trans fats. Despite being crucial macronutrients, fats contribute relatively little to athletic performance, their main role being health sustenance. Ultrarunners should focus on monounsaturated, polyunsaturated, and saturated fats while limiting or completely excluding trans fats due to their potential harmful effects on health. Foods like avocados, nuts, and extra virgin olive oil are rich in monounsaturated fats, while oily fish and chia seeds provide polyunsaturated fats. Animal products like butter and full-fat milk serve as sources of saturated fats.

Conclusion

To conclude, while food composition might not be the dominant determinant in Spartathlon ultramarathon performance, it has a role that is anything but trivial. A comprehensive understanding of protein quality and digestibility, strategic choice and timing of carbohydrates based on their nutrient density, and the skill to distinguish between different types of fats empower athletes to make educated dietary choices. These decisions not only enhance performance but also contribute significantly to an ultrarunner's overall health and well-being.