Food Composition for 25km Open Water Swimmers

At Saturday, our mission is to amplify athletic performance through strategic nutrition optimization. This strategy involves an in-depth comprehension of food composition, taking into account factors like digestibility, bioavailability, and the concentration of vital nutrients. Although food composition may not be the primary determinant of athletic performance, it significantly contributes to an athlete's nutritional health and metabolic proficiency.

Proteins: Evaluating Quality and Digestibility

The assessment of proteins requires a concentration on their quality and digestibility. Protein quality is mainly defined by the range and balance of amino acids it contains. Of the 20 amino acids, 11 can be produced internally (non-essential), while the other 9 (essential) must be obtained through dietary intake. Proteins are categorized as either complete or incomplete, based on whether they contain all the essential amino acids. However, by judiciously combining various incomplete proteins, a complementary protein that fulfills the essential amino acid requirement can be created. Foods such as chicken, beef, and fish are examples of complete proteins that contain all essential amino acids. Conversely, beans and nuts, though incomplete proteins individually, can form a complete amino acid profile when combined.

The digestibility of a protein, the percentage of consumed protein that is absorbed and utilized by the body, is another critical aspect. The Protein Digestibility Corrected Amino Acid Score (PDCAAS) offers an objective evaluation of protein digestibility, measured on a scale from 0 to 1.0. Proteins derived from animals typically achieve high PDCAAS scores, indicating excellent digestibility and quality. On the other hand, plant-based proteins often have lower digestibility, mainly due to the presence of cellulose—an indigestible component of plant cell walls—that hinders total protein absorption. Given these observations, we advise that a substantial portion of protein intake for 25km open water swimmers should originate from animal sources due to their superior quality and digestibility.

Carbohydrates: Determining Digestion Rate and Nutrient Density

The evaluation of carbohydrates primarily depends on two aspects: digestion rate and nutrient density. The Glycemic Index (GI), ranging from 0 (lowest) to 100 (highest), serves as the reference point. It measures the rate at which carbohydrates are digested and absorbed into the bloodstream. Fast-digesting sources lead to a sudden increase in blood sugar levels, thus higher GI values, while slower-digesting sources result in a more gradual increase, thus lower GI values.

The GI is relevant to both health and athletic performance. Lower GI carbohydrates, such as whole grains and legumes, often provide additional health benefits like fiber content, micronutrients, and phytochemicals. However, for athletic performance, particularly for 25km open water swimming, consuming high-GI carbohydrates like sugar during training ensures a quick supply of glucose to the bloodstream, minimizing gastrointestinal discomfort. While the GI of your carbohydrate intake is influenced by many variables, a helpful rule of thumb is the further away from training you are, the lower the GI of your carbohydrates should be.

Fats: Understanding the Types

Fat quality is primarily defined by its category: monounsaturated, polyunsaturated (including omega-3 and omega-6), saturated, and trans fats. Even though fats are a fundamental part of macronutrients, their contribution to athletic performance is relatively small, with their main role being health maintenance. 25km open water swimmers should prioritize the inclusion of monounsaturated, polyunsaturated, and saturated fats while reducing or completely avoiding trans fats due to their potential adverse health effects. Foods like avocados, nuts, and olive oil are high in monounsaturated fats, while fatty fish and flaxseeds provide polyunsaturated fats. Animal products like butter and cheese are rich in saturated fats.

Conclusion

In conclusion, while food composition might not be the key driver in athletic performance, its contribution is far from insignificant. A detailed understanding of protein quality and digestibility, the strategic selection and timing of carbohydrates based on nutrient density, and the capability to distinguish between various types of fats collectively equip 25km open water swimmers to make informed dietary decisions. These choices not only augment performance but also make a substantial contribution to an athlete's overall health and well-being.