Food Composition for 10km Open Water Swimmers

At Saturday, our goal is to boost athletic performance by strategically optimizing nutrition. This process involves a profound understanding of food composition, considering factors like digestibility, bioavailability, and the concentration of fundamental nutrients. While food composition may not be the primary determinant of athletic performance, it undeniably has a significant effect on an athlete's nutritional well-being and metabolic efficacy.

Proteins: Grading Quality and Digestibility

One major area of protein analysis centers on their quality and digestibility. Protein quality is largely defined by the variety and ratio of amino acids it encompasses. Among the 20 amino acids, 11 can be internally produced (non-essential), while the rest, the 9 essential ones, must be provided through our diet. Proteins are categorized as either complete or incomplete, depending on whether they contain all the essential amino acids or not. However, by thoughtfully combining various incomplete proteins, a complementary protein that satisfies the essential amino acid requirement can be formulated. Foods like chicken, beef, and fish are sources of complete proteins, carrying all essential amino acids. Conversely, beans and nuts are incomplete proteins individually, but when combined, they can yield a complete amino acid profile.

Digestibility of a protein, the fraction of consumed protein that is absorbed and used by the body, is another essential aspect. The Protein Digestibility Corrected Amino Acid Score (PDCAAS) offers an unbiased evaluation of protein digestibility, assessed on a scale from 0 to 1.0. Animal-sourced proteins often secure high PDCAAS scores, indicating excellent digestibility and quality. In contrast, plant-based proteins tend to display lesser digestibility, largely due to the presence of cellulose—an indigestible component of plant cell walls—that obstructs total protein absorption. Given these insights, we recommend that a substantial part of protein intake for 10km open water swimmers should be derived from animal sources due to their superior quality and digestibility.

Carbohydrates: Gauging Digestion Speed and Nutrient Density

Carbohydrates' assessment primarily revolves around two factors: digestion speed and nutrient density. The Glycemic Index (GI), which ranges from 0 (lowest) to 100 (highest), serves as the benchmark. It measures the rate at which carbohydrates are digested and absorbed into the bloodstream. Rapidly digesting sources lead to an immediate increase in blood sugar, hence higher GI values, while slower-digesting sources result in a more moderated rise, thus lower GI values.

The GI is relevant to both health and athletic performance. Lower GI carbohydrates, like whole grains and legumes, are often packed with additional health benefits such as fiber, micronutrients, and phytochemicals. However, for athletic performance, particularly for 10km open water swimming, consuming high-GI carbohydrates like sugar during training ensures a fast glucose supply to the bloodstream while reducing gastrointestinal discomfort. While your carbohydrate intake's GI can be influenced by various factors, a helpful rule of thumb is that the further from training you are, the lower the GI of your carbohydrates should be.

Fats: Differentiating the Classes

Fat quality is primarily determined by its classification: monounsaturated, polyunsaturated (including omega-3 and omega-6), saturated, and trans fats. Even though fats are an essential component of macronutrients, their contribution to athletic performance is relatively minor, with their main role being health support. 10km open water swimmers should prioritize the inclusion of monounsaturated, polyunsaturated, and saturated fats while minimizing or completely eliminating trans fats due to their potential negative health effects. Foods such as avocados, nuts, and olive oil are rich in monounsaturated fats, while fatty fish and flaxseeds are excellent sources of polyunsaturated fats. Animal-based products like butter and cheese provide saturated fats.

Conclusion

In conclusion, although food composition might not be the primary driver of athletic performance, its contribution cannot be dismissed. A thorough understanding of protein quality and digestibility, strategic carbohydrate selection and timing based on nutrient density, and the capacity to differentiate between various fat types collectively enable 10km open water swimmers to make informed dietary choices. These choices not only enhance performance but also significantly contribute to an athlete's overall health and wellness.