Exercise and Hydration

Exercise and Hydration

Performance Coach Amy Nguyen, CF- L2, USAW L1
B.S. Foods & Nutrition, M.S. candidate Exercise Physiology & Nutritional Sciences 

Water is one of our body’s essential nutrients and we need to have adequate intake of fluids daily to hydrate the cells in our body. There are many benefits to proper hydration; assisting the body in thermoregulation via sweat, lubrication to joints, moistens tissues in eyes, nose, mouth, water is the medium for transportation of nutrients and waste products of the blood and across cells, and our muscles are made up of 75% water! 

Dehydration can negatively impact performance and lead to early fatigue. 
Signs and symptoms of dehydration to watch out for are: 

• Headaches post-training/working
  
• dizziness/light-headedness
  
• Fatigue
  
• moodiness/irritability
  
• Thirst
  
• Heat intolerance during exercise
  
• Decreased endurance performance
  
• Nausea
  
• Cramps
  
• Dark, low volume urine 
  

Overall the goal is to minimize dehydration without over-drinking. Ways to check you’re getting proper hydration for yourself are urine color and sweat loss. Dark colored urine (apple juiced colored) indicates dehydration. Light yellow or straw colored is considered well hydrated. Changes in your body weight before and after exercise can be used to estimate sweat loss. Dehydration that exceeds 2% body weight loss is harmful to exercise performance. Both overhydration and underhydration - if sufficiently severe - will impair performance and pose a risk to health. When evaluating your fluid requirements, there are two things to consider: the fluid required for your general body needs PLUS the additional fluid needed for your training.

Here are a few tips to stay hydrated and replenish any fluids and electrolytes lost from sweat!

• Focus on intake throughout the day, not just when you workout 
  
• Before exercise hydration: Begin exercise well hydrated. Drink 16-20 oz of water or a sports beverage at least 4 hours before exercise. Drink 8-12 oz of water 10-15 min before exercise. 
  
• During exercise hydration: drink water (or a sports beverage for longer duration workouts is helpful as it also replenishes electrolytes, just remember to steer clear of sports drinks containing high levels of sugar) every 15-20 minutes, 3-8 oz of water, for <60 min of exercise or 3-8 oz of sports beverage for exercise >60 min.  
  
• Post exercise hydration: make sure to rehydrate! 16-24 oz of fluid for every lb. lost within 2 hours post exercise. 
  

Sources: 

1. Lopez, Rebecca M. PhD, ATC, CSCS Exercise and Hydration, Strength and Conditioning Journal: August 2012 - Volume 34 - Issue 4 - p 49-54 doi: 10.1519/SSC.0b013e318262e1d2
   
2. Collegiate and Professional Sports Dietitians Association. The Science of Hydration. 
   
3. Ellis Esther, M.S., RDN. Hydrate Right. Academy of Nutrition and Dietetics. December 2020.