Do runners need to add salt to their diet or take salt tablets before a race? - By Tara Postnikoff
Salt continues to be a hot topic in endurance sports. Should runners add or avoid salt in their diets? As with most things, the answer is: it depends.
Sodium is a key electrolyte that the body needs to function properly; having either too much or too little in the system can lead to problems. Sodium helps maintain fluid balance in your body's cells and impacts the function of nerves and muscles, including the heart.
Our individual sodium concentration level is partly genetic and these levels are tightly monitored by aldosterone, a hormone produced in the adrenal gland. Excess sodium is excreted through urine and sweat.
If you are training for an hour or less and consuming under one litre of water, then you probably don't need salt. Under these conditions it is unlikely that you will disrupt your blood sodium levels sufficiently through exercise under normal environmental conditions.
If you are training for two to four hours and consuming approximately 500 to 1000 mL water per hour, then you should take in some salt. A general recommendation of 500 mg of sodium per litre of water consumed is a good starting point to maintain sodium balance over longer training efforts. Salt can be added to your water, taken in pill format or from your fuel (such as sports drinks and gels). Check the labels, as all products are different.
With extreme heat and humidity or high intensity, your needs may change. It is important to get a good handle on your sweat volume during different training conditions to help determine how your fluid intake needs change. Additionally, women in the second half of their menstrual cycle (high hormone phase) are more at risk for needing extra sodium during exercise as a result of increased loss of sodium due to a decrease in plasma volume at this time.
In your daily diet, make sure you consume some salt, but avoid overdoing it. If you eat out frequently or you eat a lot of packaged or processed foods, you might be consuming more sodium than you think. It's important to ask about the nutrient content or check the labels. If you drink a lot of water, cook most of your meals at home and tend to shy away from the salt shaker, you might need to evaluate if you need to add a bit of sodium to your daily meals. Keep in mind that little salt goes a long way: one teaspoon of salt has roughly 3000 mg of sodium.
A final important note: If you are on medications to control blood pressure or other medications that may affect fluid balance, or if you are on a specific salt-reduced diet, your needs may be different.