Staying Hydrated in High Humidity
This time of year, I have a daily conversation about staying hydrated in high humidity and the loss of energy as the heat begins to rise in our area. Fortunately, both topics go together and they are easy to manage with a small about of attention. As the weather heats up, most runners find that they feel more fatigued after shorter runs and that they must work harder than they did just a few weeks ago.
So, how much water should you drink each day? It’s a simple question with no easy answers. Studies have produced varying recommendations over the years, but in truth, your water needs depend on many factors, including your health, how active you are and where you live. Every day you lose water through your breath, perspiration, urine, and bowel movements. For our bodies to function properly, we must replenish its water supply by consuming beverages and foods that contain water.
There are so many different thoughts on this topic after researching the specific recommendation, but I could find one key measurement that most people seem to agree with. The Institute of Medicine determined that an adequate intake (AI) for men is roughly about 13 cups (3 liters) of total beverages a day. The AI for women is about 9 cups (2.2 liters) of total beverages a day. This number is for all fluid consumption including what we get from our food. The “socially” accepted practice of eight 8oz glasses of water does not include the fluid intake we get from our food.
If we are doing nothing but living, these numbers above will keep our bodies balanced and properly hydrate. However, for most of you reading this now, we run and we run a lot. That means that we need to do more than these minimum requirements. Further research from the American College of Sports Medicine outlines the following guidelines for optimal fluid replacement for adults during exercise.
The following outline comes directly from the ACSM as a recommendation for minimum fluid intake and hydration during excessive exercise and competition:
- Individuals should consume a nutritionally balanced diet and drink adequate fluids during the 24-hour period before an event to promote proper hydration before exercise or competition.
- Individuals should drink about 500 mL (about 17 oz) of fluid about 2 hours before exercise to promote adequate hydration and allow time for excretion of excess ingested water.
- During exercise, athletes should start drinking early and at regular intervals in an attempt to consume fluids at a rate sufficient to replace all the water lost through sweating (i.e., body weight loss), or consume the maximal amount that can be tolerated.
- Ingested fluids should be cooler than ambient temperature (between 15 degrees and 22 degrees C [59 degrees and 72 degrees F]) and flavored to enhance palatability and promote fluid replacement. Fluids should be readily available and served in containers that allow adequate volumes to be ingested with ease and with minimal interruption of exercise.
- Addition of proper amounts of carbohydrates and/or electrolytes to a fluid replacement solution is recommended for exercise events of duration greater than 1 hour since it does not significantly impair water delivery to the body and may enhance performance. During exercise lasting less than 1 hour, there is little evidence of physiological or physical performance differences between consuming a carbohydrate-electrolyte drink and plain water.
- During intense exercise lasting longer than 1 hour, it is recommended that carbohydrates be ingested at a rate of 30-60 g per hour to maintain oxidation of carbohydrates and delay fatigue. This rate of carbohydrate intake can be achieved without compromising fluid delivery by drinking 600-1200 mL per hour of solutions containing 4 to 8 percent carbohydrates (g/100 mL). The carbohydrates can be sugars (glucose or sucrose) or starch (e.g., maltodextrin).
- Inclusion of sodium (0.5-0.7 g/L of water) in the rehydration solution ingested during exercise lasting longer than 1 hour is recommended since it may be advantageous in enhancing palatability and promoting fluid retention, while possibly preventing hyponatremia.
Most runners know about sodium, but sweat also contains magnesium and potassium, which play a huge role in maintaining fluid balance and muscle function. It is recommended that you 400 mg of magnesium and 4,700 mg of potassium each day and most of us do not come anywhere close to those numbers. A deficiency in either mineral can increase the symptoms of dehydration and cause extreme muscle cramps.
A well-balanced diet, rich in fruits, vegetables, grains, and legumes will ensure you get enough of these nutrients. These sources are particularly good choices.
Magnesium: Leafy greens, almonds, pumpkin seeds, tofu, flaxseeds, broccoli, lentils
Potassium: Bananas, sweet potatoes, beets, tomatoes, oranges, pomegranate juice
The above guidelines are the basic rules of thumb, but it’s important to remember that everyone’s fluid needs vary. Some people sweat more than others. To determine how much liquid to take during a run or race, you need to know your sweat rate, and that can vary between 1 to 4 quarts per hour. Keeping track of your urine during exercise is important as it is a good scale of where your body currently stands, but isn’t the only indicator.
Weigh yourself nude before a timed training run, and then again after. One pound of weight loss equals 1 pint of water loss. Calculate your sweat rate and use this to determine your fluid needs during a run or race. For example, if you lose 2 pounds during an hour run, that’s 2 pints or 32 ounces. Thus, you need 8 ounces of water or sports beverage every 15 minutes. Note the weather conditions on that day, and keep in mind that you may need to adjust your consumption if the conditions are different. You can do the sweat rate test on another day to see how different conditions affect your sweat rate.
What about sports drinks?
For most people, water is all that is needed to stay hydrated. However, if you will be exercising at a high intensity for longer than an hour, a sports drink can extremely be helpful. The calories, potassium, and other nutrients in sports drinks can provide energy and electrolytes to help you perform for a longer period of time.
Choose a sports drink wisely. They are often high in calories from added sugar and may contain high levels of sodium. Also, check the serving size. One bottle may contain several servings. If you drink the entire bottle, you may need to double or triple the amounts given on the nutrition fact label. Some sports drinks contain caffeine. If you consume a sports drink that contains caffeine, be careful not to add too much caffeine to your diet. Caffeine may cause a diuretic effect on your body. This means that you may have to urinate more often.
Personally, I recommend and use Tailwind, Nuun, Glukos and GU hydration products as they are specifically designed with the needs of runners in mind and help to balance out the sodium, potassium and magnesium lost during exercise. The table below reflects the nutritional fact label for each of these products.
If nothing else, remember that dehydration happens when you lose more fluid than you drink. When your body doesn’t have enough water, it can’t work properly. Dehydration can range from mild to severe. Symptoms of dehydration can include the following:
- dizziness or lightheaded feeling
- nausea or vomiting
- muscle cramps
- dry mouth
- lack of sweating
- hard, fast heartbeat.
Symptoms of severe dehydration can include mental confusion, weakness, and loss of consciousness. You should get emergency medical attention immediately if you have any of these symptoms.
Our goal is to help our local runners meet their training goals and help keep you running longer. Be smart this time of year and you’ll stay on track. Please let us know if you have any questions and how we can help!
Grounded Running Beaufort
864 Parris Island Gateway Unit B – Beaufort, SC 29906 – 843-986.4523