The Fundamentals of Nutrition – Part Four: An Athlete’s Need For Fluids

Did you know that losing as little as two percent of body weight through sweat can impair a rider’s ability to perform due to a low blood volume and less than optimal utilization of nutrients and oxygen?

Water (fluids) comprises about 60 per cent of the body and is the most important nutrient. It is crucial for various chemical reactions in the body, which is why hydration is imperative for optimal performance for the equestrian athlete. Riders who stay hydrated have better recovery time and higher energy levels. When a rider is adequately hydrated, their body is able to transport nutrients and oxygen to working muscles and aid in muscle repair and regulate body temperature.

The importance of fluids for the equestrian athlete

  • In sweat it dissipates heat through the skin
  • Lubricates joints and cushions the organs and tissues
  • In blood it transports glucose, oxygen and fats to working muscles
  • During exercise water absorbs heat from your muscles, dissipates it through sweat and regulates body temperatures


Dehydration occurs when you use or lose more fluid than you take in, and your body doesn’t have enough water and other fluids to carry out its normal functions. If you don’t replace lost fluids, you will get dehydrated. Your body simply dries up.

You lose water when you sweat. If you do vigorous activity such as horseback riding and don’t replace fluids throughout the day, you can become dehydrated. Hot, humid weather increases the amount you sweat and the amount of fluid you lose, but you can also become dehydrated in winter if you don’t replace lost fluids.

Unfortunately, thirst isn’t always a reliable gauge of the body’s need for water, especially in children and older adults. A better indicator is the color of your urine: Clear or light-colored urine means you’re well hydrated, whereas a dark yellow or amber color usually signals dehydration.

Symptoms of Mild to Moderate and Severe Dehydration

Mild to moderate dehydration is likely to cause:

  • Thirst
  • Fatigue
  • Headache
  • Constipation
  • Dry, brittle hair
  • Muscle cramping
  • Dry, sticky mouth
  • Decreased urine output
  • Decreased coordination
  • Sleepiness and/or tiredness
  • Few or no tears when crying
  • Dizziness or light headedness
  • Dry skin, dry mouth or dry lips

You can usually reverse mild to moderate dehydration by drinking more fluids, but severe dehydration needs immediate medical treatment. The safest approach is preventing dehydration in the first place. Keep an eye on how much fluid you lose during hot weather, illness or exercise, and drink enough liquids to replace what you’ve lost.

Severe dehydration, a medical emergency, can cause:

  • Fever
  • Sunken eyes
  • Extreme thirst
  • Rapid heartbeat
  • Rapid breathing
  • Low blood pressure
  • Very dry mouth, skin and mucous membranes
  • Extreme fussiness or sleepiness in children, irritability and confusion in adults
  • Little or no urination – any urine that is produced will be darker than normal
  • Shrivelled and dry skin that lacks elasticity and doesn’t “bounce back” when pinched into a fold

Anyone can become dehydrated if they lose too many fluids. But certain people are at greater risk than others. They include:

  • Teenagers or younger are especially vulnerable because of their relatively small body weight and high turnover of water and electrolytes. They’re also the group most likely to experience diarrhea.
  • As you age, you become more susceptible to dehydration; your body’s ability to conserve water is reduced, your thirst sense becomes less acute, and you’re less able to respond to changes in temperature.
  • Having uncontrolled or untreated diabetes puts you at high risk of dehydration. Even having a cold or sore throat makes you more susceptible to dehydration because you’re less likely to feel like eating or drinking when you’re sick. A fever can also cause dehydration.
  • Exercising outside in hot, humid weather increases your risk of dehydration and heat illness. That’s because when the air is humid, sweat can’t evaporate and cool you as quickly as it normally does, and this can lead to an increased body temperature and the need for more fluids.

So how much do we really need?

Your needs will vary widely based on age, gender, body size, health status and physical activity levels. Numerous environmental factors, such as high temperature and humidity levels, also influence water needs.

Additionally, the eight cups a day recommendation typically does not account for the water content of food, which could account for approximately two to four cups per day. Therefore, if your diet is full of water-rich fruits, vegetables, and animal products, you may not need as much water as you think. And if you’re eating soups or broths, that volume should certainly be counted towards your daily fluid intake.

Drinks to Replace Fluid Loss

Although sports drinks have been thought to replace the loss of fluids through sweating, sports drinks can cause an imbalance in your electrolytes. Sports drinks are useful only at times when exertion is heavy and the duration is in excess of 60 minutes.

Water can certainly replace fluids lost. However, water contains no nutrients or electrolytes. The best post-riding drink would be low-fat chocolate milk because it contains the perfect balance of carbohydrates, protein, fat, sugar and sodium. Chocolate milk has also been proven to increase recovery time.

Please check back next week where I will expand on the need for micronutrients, vitamins and minerals.

Ian can be reached at You can also follow his nutrition tips on Facebook or visit