It was a hot September day...over 90 degrees. I was with some friends doing an adventure/obstacle course race. Because there were so many people, there were lines at the obstacles and we wound up being on the course for over 3 hours.
I felt awful — headachy, confused and sluggish. I assumed I was dehydrated and kept drinking more and more water. As soon as we crossed the finish line, I collapsed and my arms and legs seized up.
In the medical tent I told the doctor I was dehydrated and he said, “No, you’re OVER HYDRATED. It is a very serious difference.”
I had drank TOO MUCH water and diluted the sodium concentration in my blood. After I was rehydrated appropriately and released from the tent, the doctor told me to be sure that in the future when exercising for extended periods of time and (or) in the extreme heat that I should always be sure to take in electrolytes.
Mine was an extreme case for sure, due to the heat and the extended period of time we were exerting ourselves. Luckily, most athletes can avoid dehydration simply by consuming water before, during and after exercise.
So when is a sports drink necessary and when will water do the job?
Unlike water, sports drinks contain carbohydrates (in the form of simple sugars) and electrolytes. Electrolytes are minerals such as sodium, calcium, potassium and magnesium. They help to keep the body’s balance of fluids at proper levels.
Common grocery store sports drinks usually contain just two of these vital electrolytes — sodium and potassium. These elements help to pull water into cells and keep it there. Potassium also helps to regulate muscle contractions, while carbohydrates are used for energy during exercise.
So why not just consume sports drinks during warm weather exercise to be on the safe side? There are a few downsides:
- One 20-oz sports drink has 9 teaspoons of sugar.
- 135 calories in a 20-oz beverage are from just sugar. Many 30-minute activities will burn just slightly over that.
- Athletes often have a hard time breaking down sugar during endurance events and can experience stomach upset; although recent changes to the ratios of carbohydrates and electrolytes have led to improvement in this area.
- Calorie cost and financial cost can add up for frequent exercisers.
Plain water is sufficient for hydration for activities such as walking, weight lifting, casual bike rides and any activity that takes less than 60 minutes outside.
It is suggested that being hydrated before you begin to work out in the heat is as important as consuming beverages during your routine. A suggested ratio is 2 cups of water before, 20-24 oz per hour and some water or other liquids upon completion.
A clear, yellow, odorless urine stream is a sign of adequate hydration, while a headache and or a decrease in sweating is an indication that dehydration could be occurring and should be addressed.
Sports drinks should be used for extended periods of continuous exercise or in extreme heat and humidity. Continuous exercise would be defined as running, cycling, or other aerobic events lasting 1-4 hours or more.
Of course, water and sports drinks are not your only choices. Vitamin waters, caffeinated drinks such as coffee and tea, and even soda all contribute to hydration.
According The Hydration Index, milk beats all other beverages, including sports drinks, in preventing post exercise fluid loss. Milk also includes protein, fat and many nutrients that promote post exercise recovery.
Taste, availability and preference will determine which works for you. Experiment with different beverages and combinations to see what gives you the best results.
As a distance cyclist, I spend 3-4 or more hours on my bike every Sunday, along with shorter rides during the week. I have found a diluted sports drink in one bottle, water in the other and a halfway stop for cold coffee to be the magic combination that works for me. I make sure to consume one bottle every hour, alternating between the sports drink and the water.
On very hot days I also eat a salty snack when I stop. I keep my experience of 5 years ago and the lessons that I learned in the back of my mind and have never had another bad experience.
As always if you have any questions about this column, related issues or any fitness related concerns please do not hesitate to contact me.
Megan Leipholtz CPT