Say [Na] to Low-Sodium!

Grab Your Salt Shaker

Sodium, in particular salt, is one of those terms which has been particularly vilified by food marketing over the last few decades. With many food companies jumping on the bandwagon of low-sodium product releases after the discovery of higher dividends being associated with the term. Similar to the low-fat movement the claims of reduced sodium in products leading to increased health are led by the increase in product sales by health conscious consumers rather than any scientific facts.


Effects of Sodium In and Around Training

While responsible for many functions in the body, from the lens of the athlete sodium is responsible for regulating blood volume and blood pressure. Undertaking high-intensity training requires a higher blood volume to best deliver oxygen and nutrient delivery into the cells. While also more efficiently removing fatigue toxins during high intensity exertion and muscle contractions.

On the other hand, low blood volume caused by low sodium can be disastrous to both athletes and the general population. Studies have concluded that a low-sodium diet reduces the level of oxygen and nutrients able to be delivered into the muscles. Long term effects of this sodium depletion translated to severely diminished recovery and overall muscle weakness.

Further to this, sodium as an electrolyte has an impact on electrolyte metabolism. Including potassium which primary roles include regulation of the cardiac and skeletal muscles and vagus nerve innervation; controlling our heartbeat. Potassium is both reliant on sodium to maintain cell integrity and for its delivery into the muscle cells.

Looking on from potassium there are significant effects on Aldosterone production. Aldosterone is a hormone released within the body in response to metabolic stress. With the main effect of aldosterone secretion being a reabsorption of sodium through the kidneys. Meaning that sodium initially intended to be excreted from the body is retained due to the presence of Aldosterone hormone.

While it is normal to have low levels of aldosterone circulating through the body. For an Athlete, who is regularly losing sodium through sweat and exertion it can be increasingly detrimental to eliminate sodium from their diet. As increased Aldosterone causes sodium retention there is no sodium in the urine at all. Resulting in diminishing water leaving the body as water, a negatively charged molecule, follows sodium which is positively charged. Overall, leading to water retention.

Secondary to this, the hormone increases urinary excretion of potassium. Up to fifty times the amount of regularly excreted potassium is present in the urinary output when Aldosterone levels are high. Leading to muscular weakness, cramping, diminished performance and flat muscular appearance. On top of the already present water retention.

Leading to muscular weakness, cramping, diminished performance and flat muscular appearance. On top of the already present water retention.

It is worth noting that an Athlete who has been trying to avoid sodium for a prolonged period may experience some osmotic imbalance when returning or starting a high-sodium diet. This is temporary, the water retention caused by the osmotic imbalance will dissipate with consistent high water and sodium intake. As the body returns to the new equilibrium the Athlete will notice higher urinary output, increased sweating, increased ‘pump’ in training, fuller muscles in the gym and increased performance.

Optimal Sodium Intake

Depending on the source you read the daily recommended sodium intake for an average adult will vary between 2000-3000mg per day. Those recommendations for Athletes, however, will generally sit somewhere between 3000-5500mg per day across all food sources. While there is no current standard diary recommended intake in the Strength & Conditioning world, it is safe to assume a diet higher in sodium will reap far greater better benefits for the Athlete; Both aesthetic and performance aspects than that of a low-sodium diet.

Ruby Cooke
Sports Nutritionist | Lifters League

References

  1. Abel, S. (2008). Sodium, Your Secret Weapon [Blog]. Retrieved from www.t-nation.com/lean-build-eating/sodium-your-secret-weapon/
  2. Efferding, S., & McCune, D. (2019). The Vertical Diet & Peak Performance 3.0 (pp. 70-72).
  3. Israetel, D., Davis, D., Case, D. and Hoffmann, D., n.d. The Renaissance Diet 2.0. 1st ed.

Archives