Trails Collective

The Aid Station: Hydration and Endurance Performance

Hydration and Endurance Performance

Author: Lauren Burdick

Miles and Macros

Hydration plays an important role in your body’s functions – during exercise and day-to-day. Water is needed to maintain adequate blood pressure and it delivers blood to the brain, liver, and kidneys. If fluids are restricted your exercise performance can be negatively affected.

During exercise fluid demands are higher so that oxygen and blood flow can be delivered to its working muscles. Water is a critical component in this process because approximately half of your blood volume is water.

The first training adaptations your body makes is the increase in blood volume. An increase in blood volume is accomplished by water retention. Your body becomes thirsty, and your urine output decreases, trying to store as much fluid as possible. These adaptations are set to increase maximal cardiac output and your aerobic fitness.

Proper hydration is important for cooling down your body appropriately while exercising. The extra blood flow increases sweating, and the evaporation of this sweat decreases your skin’s temperature and cools your blood before it returns to your core. Dehydration would cause the body to overheat, and your cardiac output would decline.

Here are some tips with hydration while you are covering your miles.

• How can you maintain hydration during your long runs?
  Both overconsuming and under consuming fluids during exercise can carry certain risks and each athlete may need to use trial and error to find the sweet “spot”. For races up to two hours, it may be safe to use the “drink when thirsty method” to maintain proper hydration. When you are out running for longer periods of time it is suggested that you consume 30 ounces of water an hour on a hot day or 20 ounces on a cooler day. This measurement does not consider the
  sweat rate of the individual and, again, it is best to practice your hydration during your training runs to find out how much hydration is right for you.

• Watch Electrolyte Balances to Avoid Over-Hydration
  To maintain hydration, athletes usually turn to sports drinks (Gatorade, Nuun, Rocktane, etc.). Ingesting loads of plain water isn’t an effective method of increasing your water storages. Consuming just water lacks the electrolytes that your body needs to hold onto fluids longer and can lead to hypoatraemia (low blood sodium). Excessive water consumption, dilutes sodium and the body excretes it, making you become dehydrated. It is suggested that you train with both water and an electrolyte drink of your choice. Once again, the exact quantity is individual based and experimented with on the athlete’s training run.

• Post Run
  The goal of hydration post run is to replace any fluid deficit you lost during your event. Replacing these fluids after your run will restore hydration, improve recovery, reduce hypo-hydration symptoms, and decrease post-exercise fatigue. To know how much you need to hydrate post event, it is best to keep a eye on your body weight to help monitor how much sweat you have lost. Hydration is something that can often be dismissed. Staying hydrated adds tremendous value and importance to the everyday functions of our bodies. Staying hydrated helps maintain blood, improves circulation, helps with delivery of oxygen and nutrients to your working muscles and enhances performance.