Hydration for Ultramarathon Mountain Cycling

At Saturday, our unwavering commitment lies in amplifying athletic performance via informed sports nutrition. The current discourse explores the critical role of hydration during training, highlighting essential elements like fluid intake, the function of sodium, and their cumulative impact on performance. For ultramarathon mountain cyclists, establishing and preserving optimal hydration levels are key components of peak performance.

The Impact of Dehydration on Performance

Even a slight decline in hydration, close to 2%, can initiate a decrease in cardiac output, defined as the amount of blood the heart pumps per minute. This decrease means the heart must exert additional effort to circulate blood, leading to a downturn in performance.

As dehydration becomes more severe, there can also be a loss in muscle power. This is tied to a decrease in blood volume, which affects the efficient transport of nutrients and oxygen to the muscles. Moreover, as the body loses more fluids, its capability to cool itself via sweating diminishes. This can result in a rise in the body's core temperature, with further detrimental effects on performance.

Striking the Balance: Hydration and Sodium Levels

During physical activity, maintaining the right balance of fluid and sodium levels is critical. Dehydration is a significant issue, but overconsumption of water without enough salts can lead to hyponatremia, characterized by low sodium levels in the blood plasma. It is important to note that symptoms of hyponatremia, such as headaches, confusion, fatigue, and muscle weakness, closely resemble those of dehydration.

To maintain appropriate sodium levels in the blood, consuming a hypotonic solution during training is recommended. However, athletes frequently do not consume enough, and a hypertonic solution may be necessary to compensate for the sodium lost through sweat.

Appropriate Fluid Consumption Rates and Concentrations

Most athletes can consume around 0.8-1.5L of fluid per hour of exercise without experiencing gastrointestinal discomfort, provided the concentration of sugars and electrolytes in the fluid is not considerably different from that of body fluids (10-14% concentrations are generally ideal). During shorter exercise durations, less than three hours, consuming high-concentration carbohydrate solutions can prove beneficial as the requirement for carbohydrate fuel outweighs the need for ideal water replacement.

Tailored Electrolyte Intake

Electrolyte intake during training must be customized to individual needs. Sodium needs generally range between 500-1500mg/L and are dependent on factors such as sweat rate, sweat composition, temperature, and humidity. As a general rule, if you perspire more, you will likely need to consume more sodium per litre to balance out sweat losses.

Options for Sodium Replacement

There's a plethora of options available for sodium replacement, encompassing sports beverages, gels, and tabs. However, a more economical option is standard table salt. Sodium citrate is another effective choice, as it provides a greater number of sodium ions compared to table salt. Sodium citrate splits into three sodium ions and one citrate ion, while table salt dissociates into one sodium ion and one chloride ion. This makes sodium citrate a more potent source of sodium, causing less gastrointestinal strain.

Conclusion

For ultramarathon mountain cyclists, effective hydration is at the heart of achieving top performance. It is essential to balance hydration and sodium levels to prevent dehydration and hyponatremia. Adjust your fluid and electrolyte intake to match your unique physiological needs and environmental conditions. Understand that recognizing and addressing your individual needs is the cornerstone of a successful hydration strategy.