Electrolytes and Staying Hydrated

What are Electrolytes?

Electrolytes are molecules with an electric charge that increase fluid absorption and retention which can influence muscle and nerve function. When we sweat, we lose electrolytes, particularly sodium and chloride (“NaCl”, or salt) and lesser amounts of potassium, calcium, magnesium, and other minerals.

Electrolyte Replacement

Determining when, how much, and if you need to replace electrolytes varies between people and can depend on a host of factors, particularly how much sweat you are losing and if you are a “salty” sweater. Electrolyte replacement generally becomes important if exercise takes place for more than 2 hours.

Since sodium is the electrolyte most commonly lost, it is recommended in endurance events to consume up to 1 gram of sodium (Na) per hour. That equates to approximately 2.5 grams of salt, or just under ½ tsp of salt.

For the “average” person not training at a competitive level, fluid replacement is likely more important than electrolyte replacement. Making your own rehydrating drink or consuming commercial sports drinks are typically suitable. In addition, if you consume foods before or during exercise, these contain electrolytes (especially salt), so additional supplementing becomes less important in these cases.

The Importance of Hydration in Sport

Sweating causes an increase in core body temperature and heart rate with accompanying fluid and electrolyte loss that can lead to dehydration. Dehydration can lead to a number of compromises in performance:

Decreased cardiovascular function
Decreased ability to regulate body temperature
Increased perception of effort
Increased risk of heat illness
Impaired skill and concentration

Even mild dehydration (the loss of < or = 2% of body mass) can affect core temperature, perceived exertion, and impair performance.

Determining Your Hydration Needs

It is impossible to ‘train’ your body to handle dehydration, which is why it is important to learn what your specific hydration needs are when exercising.

There are a few ways to determine your hydration status:

Take your weight before and after 1-hour exercise sessions, particularly during extreme heat. This will tell you how much fluid you have lost and help you develop a hydration protocol for yourself. 1 kg of weight lost is equivalent to approximately 1 L of fluid loss. You will also want to limit your fluid loss ideally to less than 1% of your body weight, but note that this may vary among individuals. For example, a 150-pound athlete should aim
to lose less than 1.5 pounds after one hour of activity.
Monitor the color of your urine – it should be a pale yellow or clear.
Take a urine dipstick test before training sessions to measure the ‘specific gravity,’ which indicates hydration status.

On average, the body needs approximately 600-1000 ml for every hour of exercise, depending on sweat rate, air temperature, humidity, gender, body size, fitness level, and training intensity. Intake of 400-800 ml/hour is a good starting point.

Staying hydrated

One of the most effective ways to stay hydrated for sport is to be fully hydrated before beginning the activity. Fluid may take up to 60 minutes from the time of ingestion to be transported around the body’s circulation and become useful for physiological processes. Therefore, attempting to offset fluid losses during prolonged exercise can be difficult.

During prolonged activity, there should be frequent (every 5-20 minutes) ingestion of small amounts of fluid (150-200 ml). Fluid intake should be increased in hot and humid environments.

Re-hydration Summer Drink Recipe

The following is a re-hydration drink recommended for use only in adults engaging in exercise in which there is significant sweat loss, particularly in endurance activities lasting ~2 hours or more.

950 ml water
½ tsp baking soda
½ tsp table salt
2 tbsp sugar (in the form of maple syrup or honey)*
A splash of lemon and lime juice to taste

*Sugar helps with absorption of electrolytes. The amount of sugar can vary depending on taste and duration of activity. Typically, 2 tbsp of sugar = 30g of carbohydrates, which is recommended when engaging in activities over 2 hours in duration. This amount can be decreased if the activity is of shorter duration or decreased intensity.

Looking For More Guidance With Your Nutrition?

If you have more questions or need help creating a nutrition plan for yourself, Dr. Parsi, Naturopathic Doctor, offers in-person and virtual consultations. Call 416-306-1111 or book online with Dr. Parsi today.

Disclaimer: This blog is for general informational purposes only and does not constitute the practice of medicine or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this blog is at the user’s own risk. The content of this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard, or delay in obtaining, medical advice for any medical condition they may have, and should seek the assistance of their health care professionals for any such conditions.