Electrolytes Part 4: How Electrolytes Play a Role in Performance
To understand how electrolytes impact performance, we need to first understand what happens during exercise. When you exercise, your body uses various fuels to help provide energy to power working muscle. Muscle contraction requires energy and produces heat. The average human body temperature is approximately 98.6°F (37°C). However, the more energy you exert the more heat that is produced, which can cause body temperature to rise. The body prefers to stay near the norm and keep cool. Therefore, the nervous system can begin to sense that it’s overheating and will trigger the body to begin to take action to control body temperature.
Sweating is a normal response to exercise. The human body actually has millions of sweat glands, which are critical to help regulate body temperature. In order to prevent an excessive amount of heat from building up, the body will respond by increasing blood flow to skin and producing sweat. You’ll often hear that sweat contains toxins and sweating can help release those toxins. However, this is just another myth. Sweat is primarily made up of water and also contains variable amounts of electrolytes (minerals). Sodium can move out of cells and into the sweat glands where water quickly follows. The increased pressure within the sweat gland forces water and minerals to get pushed out through the pores of the skin. However, the body doesn’t just simply cool the body down when we sweat. Heat is only released when sweat evaporates from the skin into the air.
Electrolytes play a large role in hydration status. Electrolytes are not hydrating. It’s water that hydrates the body. However, electrolytes help to regulate fluid balance. Remember that fluid in the body and sweat are more than just water. Instead, they contain varying types and amounts of electrolytes depending on where found in the body. For example, sodium is the main mineral found outside of the cell (extracellular) whereas potassium is the main mineral found mostly inside the cell (intracellular). In all, maintaining fluid balance is essential for health and performance. Too much or too little of any nutrient can impact overall performance.
Dehydration (hypohydration) occurs when the body fluid falls below body’s needs. This can result from an inadequate intake of water or excessive water losses. Water can be lost through metabolism, breathing, skin, sweat, urine and bowel movements. If fluid levels get too low, then it can be hard to rehydrate and replenish electrolytes quickly. Moreover, performance can become impaired by dehydration. In fact, as little as 2% dehydration can result in a decrease in performance. Dehydration can cause cell function to become impaired, reduction is blood volume, decrease sweat rate, increased core temperature, increased rate of muscle glycogen use and can largely contribute to fatigue. Recognize early signs of dehydration which include thirst, flushed skin, premature fatigue and increased perception of effort.
Overhydration (hyperhydration) occurs when the body fluids are above body’s needs. This can result from an excessive water intake. Generally, this is only temporary, because the renal system can normally respond by increasing urine output. However, the renal system can be overwhelmed by excessive amounts of water too fast. Drinking too much water can dilute electrolytes in the body, which can potentially produce negative consequences on performance and overall health. In extreme cases, when there is a significant loss of electrolytes, consuming too much water, without also replacing electrolytes, may result in hyponatremia.
1. Have an individualized plan
2. Create a healthy hydration habits
3. Understand your sweat rate
4. Monitor hydration status
4. Track pre- and post-exercise bodyweight to assess water losses and replenish as needed
6. Hydrate with cool fluids around activity (before, during, after)
7. Hydrate before activity to top off fluid levels
8. Take breaks during activity to hydrate. Hydrate at regular intervals during activity to help replace water lost through sweat
9. Rehydrate following activity
10. If activity is greater than an hour or if sweat losses are excessive, then rehydrate with water plus electrolytes
It’s important to understand - water balance can never be perfectly matched. Hydration needs vary from person to person. It’s also important to understand that too much or too little can be consequential to performance. Understand your personal needs and understand how your body responds. Under normal conditions, fluid balance is tightly regulated, however exercise may pose a challenge for fluid balance. Remember, sweat is made up of both water and electrolytes. Rehydrating with electrolytes can help restore electrolyte balance. Moving forward, make hydration and electrolytes part of your training plan.