by Coach Matt Russ

I recently had an athlete ask me if he could load his body with water prior to an event just as someone would load carbohydrate. The answer to this question is no and yes. Your body stores carbohydrates in the muscles and liver as glycogen. This stored energy awaits utilization on race day. Water, however, moves through the body very quickly, as you probably have experienced. Once your body senses it has reached a point of hydration, it triggers the kidneys to move the excess fluid through your system. Any water you try to load would be quickly eliminated; if it was not, you would blow up like a balloon.

Although your blood volume can increase rapidly with fluid intake, your cells hydrate much more slowly. It can take up to several days to fully hydrate on the cellular level after being dehydrated. The implication is that, although you have been drinking plenty of water the day before a race, you could reach the start line still slightly dehydrated on the cellular level.

The solution to this is to pay particular attention to your hydration several days before an event. Hydrate often, especially during and after training. Clear urine is a good indicator although it may be affected by vitamin intake.

By Coach Matt Russ

I recently had an athlete ask me whether he could load his body with water before an endurance event the same way an athlete carbohydrate-loads before a race.

The answer is both yes and no.

Your body has a well-developed system for storing carbohydrates. When you consume carbohydrates, your muscles and liver store them as glycogen. That stored fuel remains available for use when you need it on race day.

Water works differently.

Your body does not have the same ability to store large amounts of excess water for later use. Fluid moves through the body relatively quickly, as anyone who has tried to drink large quantities of water at once has probably experienced. Once your body senses that it has reached an adequate level of hydration, the kidneys begin eliminating excess fluid.

In other words, you can't simply drink gallons of water the night before a race and expect to start with a massive reserve of fluid. Your body will generally get rid of what it doesn't need. If it didn't, you'd eventually look—and feel—like a balloon.

Can You Increase Hydration Before a Race?

There is an important distinction between increasing blood volume through fluid intake and fully hydrating the body's cells.

Fluid intake can increase blood volume relatively quickly. Cellular hydration, however, is a slower process. If you have become dehydrated, restoring normal hydration throughout the body can take considerably longer than simply drinking a large amount of water.

This is why drinking plenty of water the day before an event isn't necessarily a guarantee that you are starting the race fully hydrated.

You may feel like you have done everything right, but your hydration status is influenced by what you have done over the previous several days, not just the previous several hours.

Start Hydrating Several Days Before Your Event

The better strategy is to make hydration part of your race preparation several days before the event.

Drink consistently throughout the day and pay particular attention to hydration during and after training. Rather than attempting to force large quantities of water into your system immediately before a race, establish good hydration habits well in advance.

This is particularly important for endurance athletes preparing for events such as triathlons, Ironman races, cycling events, and long-distance running races, where maintaining adequate fluid balance can become increasingly challenging as the event progresses.

One simple way to monitor hydration is to pay attention to urine color. Pale or light-colored urine is generally a useful indication that you are adequately hydrated, although urine color can be influenced by factors such as vitamins, supplements, medications, and certain foods.

The lesson is simple: don't try to water-load at the last minute. Just as successful carbohydrate loading is a process rather than a single meal, effective hydration should be approached as part of your preparation in the days leading up to an event.

Arriving at the starting line properly hydrated begins well before race morning.