Sodium is an electrolyte that our body needs in order to survive, due to its role in regulating blood pressure and fluid balance. However, too much sodium, in the long term, can result in elevated blood pressure, also known as hypertension. This can increase the risk of developing other chronic conditions, such as type 2 diabetes and heart disease. Not enough (in the short term) can lead to hyponatraemia, also known as low levels of sodium in the blood. This can lead to nausea, vomiting, headache, and eventually seizures and coma in severe instances. So, how much sodium to we actually need?
Sodium is most commonly found as salt in the food supply. It is present both as a natural occurrence in many foods, including fruits, vegetables, lean meats, legumes and fish, but also as a preservative in many packaged foods. Additionally, you will find it in many sports foods, as some people do require a little extra, especially when exercising for long periods of time or in excessive heat.
Adequate daily intake of sodium is between 460-920mg per day, which equals 1.15-2.3g salt, or less than half a teaspoon. The safe upper limit for people participating in every day activity, including those who exercise is 2300mg of sodium per day, or 6g of salt. Most Australians consume more than 10g of salt per day!
However, as previously mentioned, there are some subgroups who do require extra sodium, this being endurance athletes. For sessions under 90 minutes in length, sodium requirements are usually able to be met simply through adequate fueling before and after the event, and do not need to add any additional sodium in on a daily basis. Above this, additional fuel during the event, through use of electrolyte containing sports drinks, gels and/or chews will suffice. Those who participate in ultra endurance events need to pay a little more attention, with sodium requirements often reaching 500-1000mg per hour during the event. The exact amount required is individual, and dependent on how much salt is excreted in your sweat. I will often ask my clients to train in a dark coloured t-shirt, and check for white marks once it is dry, along with pre and post weighing to ascertain how much fluid and salt has been lost.
Some people find use of salt tablet can help with avoiding cramps. The science behind this indicates it is more likely to help those who are susceptible to cramps avoid them, however sodium is unlikely to be the sole contributor to an individual being struck with cramps.
For those of you who do not require extra sodium, and who may need to actually cut back, following are some easy ways of doing this:
- Choosing reduced salt or no added salt products
- Avoiding adding salt to food when cooking, or once it is ready
- Limit intake of high salt options, such as chips, biscuits and sauces
- Include more plant based foods
- Choose products with less than 120mg sodium per 100g
Take home message? Most Australians consume too much sodium, and need to cut back on their daily consumption. However, there are specific sub groups who do require extra sodium in order to help them through their training and events. If you’re unsure, don’t hesitate to contact us for an individual assessment.
Chloe McLeod is a dietitian at BJC Health.
This blog focuses on diet & nutrition generally and diet & nutrition in relation to the treatment of arthritis and arthritis-related diseases. Contact us if you'd like our help in managing diet-related health issues.