Beat the Heat!

Amy Goodson, MS, RD, CSSD, LD
Christina Strudwick, MS, RD, CSSD, LD

As the weather warms up in Texas, paying attention to your hydration is essential! Just a two-percent level of dehydration in the body can equate to an approximate 10-percent decrease in athletic performance. The key is not to over-drink, but to drink smart and stay well-hydrated! Check out these pre-, during- and post-exercise hydration tips:

Pre-Exercise
• Check urine color before beginning exercise
• 2-4 hours pre-exercise: 5-7 mL fluid per kg body weight
      - 1 oz per 10 lb of body weight
      - Generalized: 16-20 oz fluid (approximately one bottle water or sports drink)
• 2 hours pre-exercise: If profuse sweating is expected, drink another 3-5 mL fluid per kg body weight
      - 0.6 oz per 10 lb of body weight
      - Generalized: 7-12 oz fluid
• 10 minutes before workout/game: 5-10 oz fluid (water or sports drink)
• No pre-exercise electrolyte recommendations
      - Encourage salty food intake like pretzels, tomato juice, pickles, soups, and other salty snacks

During Exercise
• Very individualized to athlete’s sweat rate, but a general rule is 5-10 oz (water or sports drink)
  every 15-20 minutes
      - One medium mouthful = about 1 oz
• After one hour of exercise, make sure you are consuming some sports drink for carbohydrate
  and electrolytes
      - 30-60 gm carbohydrate per hour
      - Upon practice, it is possible to consume up to 1 gm carbohydrate per kg body weight per hour
      - General electrolyte recommendation: 1 gm salt/1 L fluid
• If it is extremely hot and humid, rely more on a sports drink such as Gatorade or Powerade
  to ensure adequate carbohydrate and electrolytes (sodium, chloride, potassium); you may also
  need to drink a greater quantity.
• The purpose of a sports drink is to provide carbohydrate during exercise for energy
  and maintenance of blood-sugar levels, provide electrolytes (sodium, potassium, chloride) to aid
  in hydration, and provide fluid to prevent or minimize dehydration.
• Choose a sports drink that is 14-17g carbohydrate per 8 ounces, which is optimal for athletic
  performance/training and gastric emptying during training.
• Sports drinks should be used if exercising longer than one hour or exercising in extremely hot and
  humid conditions!

Post-Exercise
• Consume 16-24 oz of fluid (water or sports drink) for every pound lost during exercise
• If needing rapid rehydration due to multiple matches, two-a-day practices, or other sporting events,
  consume 24 oz of fluid for every pound lost (150%)
• Including sodium post-exercise (sports drinks and/or salty foods) can help retain ingested fluids
  and stimulate thirst
• Sweat rate
      • Pre-exercise weight – post-exercise weight = lbs lost
      • Multiply lbs lost by 16 to get into ounces
      • Add fluid consumed during exercise
      • Result = how many total ounces of fluid were lost during exercise
      • Take total number of exercise minutes and divide into 15-20 minute segments
      • Divide total ounces needed by 15 or 20 to get how many ounces should be consumed
        at each drinking interval