Today I’ve got a long run of 15 miles planned so my topic of water & electrolytes is especially important. Today, I am bringing back my series of Nutrient Requirements for Active People. If you missed my previous articles in this series check them out:
Today’s topic will focus on water & electrolytes.
Water and electrolytes are important for all active people but I’m going to focus particularly on endurance sports because that’s really where these nutrients are critical.
For runners the term electrolyte might be second nature but I realize not everyone knows what an electrolyte is. And truthfully a lot of runners probably use the term electrolytes without truly knowing what it is.
This is a term to describe sodium, potassium & chloride. Electrolytes work to regulate our fluid status. During exercise, we lose electrolytes through our sweat. Potassium & chloride losses are moderate but sodium losses can be substantial. That is why sweat often tastes salty or you even find salt crystallizing on your body post workout.
How much do we need?
Sodium & chloride are critical electrolytes for endurance athletes. Generally sodium and chloride are found together. Sodium chloride = salt
Endurance athletes often require higher amounts of sodium and chloride than the recommended adequate intake of 1500mg and sometimes even higher than the upper intake level of 2300mg. How much? It really depends on the runner’s sweat losses and ideally should be individualized based on water weight lost.
Now does this mean an endurance runner should be adding salt to all their foods and eating processed foods all the time? No! The excess sodium and chloride intake can be found in sport beverages taken during the activity itself. Higher sodium or chloride intakes outside of exercise are not necessary.
As for potassium, while it also plays an important role in fluid balance the levels don’t drop near as much during activity and generally the amount of potassium consumed in the diet is sufficient to support fluid balance during activity. However, most sport beverage contain potassium anyways.
Water – why is it important?
Water is vital to life. It maintains our blood volume, temperature and muscle contraction. Severe dehydration during sport can be life threatening. Mild dehydration can lead to cognitive impairment and decreased performance.
How much do we need?
The American College of Sports Medicine recommends 2-3mL water per pound body weight at least 4 hours before exercise. So for example a 130lb person should take 260-390mL water prior to exercise.
The answer to this gets pretty complicated. It’s difficult to give an exact amount to drink because it varies highly on the temperature, intensity of exercise and individual sweat rates. But a general guideline is 400-800mL/hour of exercise.
After exercise consuming regular meals & water should adequately rehydrate the body. But if you are participating in multiple sporting events or training with limited recovery time the ideal is to weigh yourself before and after activity and consume about 2.5L water per pound of body weight lost to rehydrate.
On a day to day basis urine colour is always a good indicator of hydration status. Urine should be a pale yellow if you are properly hydrated. A dark colour indicates dehydration and you should consume more water immediately.