Exercise and hydration in the heat
Each season and sport brings its own set of challenges — for spring and summer athletics, outside temperatures require careful thought about body temperature regulation and adequate fluids, in addition to the consideration of nutrition for peak athletic performance.
It’s not uncommon to lose up to four cups of fluid (or two pounds of body weight) per hour of exercise in hot, humid conditions. The resulting decrease in strength and endurance can be surprisingly dramatic. In fact, dehydration can be the biggest hindrance to optimizing both training and recovery — with the effects taking hours or even days to recuperate from. Not only performance can suffer, potentially life-threatening symptoms of heat illness can appear if thirst is ignored or fluids are limited.
Signs and symptoms of dehydration include:
- Increased thirst
- Headache
- Muscle cramps
- Lack of concentration
- High perceived exertion during activity
- Trouble tolerating the heat
- Delayed recovery
- Dark urine and decreased frequency of urination
Take a peek at your urine. What color is it? If it’s dark and there’s not much of it, you need to drink more. If it’s pale yellow (think lemonade), you’re probably close to proper hydration.
So how much should you drink?
To stay hydrated and perform at your best, follow these simple rules:
- Drink 1-2 cups of fluid with meals — water, milk and 100 percent juice all count. Carry a water bottle with you throughout the day and sip on it regularly.
- Take a break every 15 to 20 minutes during exercise and drink two to three big gulps of fluid.
What should you drink before, during and after exercise?
Individual preference, including taste and energy needs, affect what you choose to drink.
For exercise lasting less than 60 minutes, water is adequate. For activities longer than 60 minutes in duration, or for training camps or long competitions, choose a beverage with carbohydrate and electrolytes.
Many sports drinks are designed to replace fluid and provide needed energy in the form of carbohydrates; most also contain electrolytes such as sodium and potassium, which are lost in sweat. For more on sports drinks see Sports drinks, gels and bars – oh my! Milk, both white and chocolate, also provide a natural source of carbohydrate and electrolytes.
Refueling with fluid after exercise is important. Take advantage of the recovery benefits of milk by enjoying a glass of ice cold white or chocolate milk within 30 to 60 minutes of completing your activity. Both deliver sufficient carbohydrates to refuel muscle energy stores in addition to providing protein necessary to rebuild and repair muscles after activity.
One word of caution: While uncommon, it is possible to drink too much fluid, which can lead to a condition called hyponatremia — when excess fluid intake causes sodium levels in the body to become diluted.
Sodium is an electrolyte that regulates the amount of fluid in your body cells; too little sodium can cause cells to swell. Symptoms of hyponatremia may be similar to those which are seen with dehydration, so it’s important to monitor weight changes, with a resulting weight gain signaling problems with excess fluid intake.
Athletes can train harder and perform better with proper nutrition. Visit WesternDairyAssociation.org to read more about milk as an exercise recovery beverage and learn how to eat for peak athletic performance.
