Sodium is essentially the most talked about electrolyte… it’s usually talked about in relation to hydration however what precisely is it and what precisely does it do?
Sodium performs a job in fluid steadiness, absorption of water, regulation of blood stress and muscle contraction. Sodium, because the principal electrolyte (cation) within the extracellular fluids, serves primarily to take care of regular physique water quantity, the steadiness of water between the within and outdoors of cells, and blood stress. Regular physique fluid ranges of sodium are essential for nerve impulse transmission and muscle contraction. The physique has efficient hormonal management mechanisms for coping with broad variations in dietary sodium consumption (1).
Sodium and fluid steadiness
Sodium helps with water absorption from the intestine. Drinks that comprise carbohydrate and sodium can have elevated absorption of water and as soon as it’s absorbed the water will even be higher retained (lowered urine output). That is the primary motive why sodium will be present in so many sports activities drinks. We are going to focus on this subject in additional element in one of many future blogs as effectively.
As a result of sodium is a very powerful cation within the extracellular fluids it serves primarily to take care of regular physique fluid steadiness and osmotic stress (the quantity of fluids inside and outdoors the cells in addition to general quantity within the physique). Modifications in sodium concentrations in a single compartment will often end in a motion of water between compartments. For instance, if sodium focus within the blood drops, water will transfer into tissues (and one in every of these tissues will be the mind which may have severe penalties).
Sodium and blood stress
Elevated consumption of high-sodium meals regularly will increase your blood stress. If blood stress is chronically excessive this places a pressure in your cardiovascular system, which may ultimately result in worse heart problems outcomes over time. For many years it was assumed that sodium did this by inflicting your physique to carry onto extra water, nonetheless it’s now believed that the reason being far more complicated and never totally understood (2).
That stated, people with hypertension can profit from sodium restriction and this will cut back each systolic and diastolic blood stress. However this impact is principally seen in people with a pre-existing situation of hypertension. Though there will be small advantages amongst individuals with regular blood stress, these results are often not clinically related (or probably non-existent). In different phrases, within the context of blood stress, sodium is just some extent of concern for some people in some conditions.
Sodium and muscle cramping
Sodium is usually related to muscle cramping. There is no such thing as a query a couple of function for sodium in muscle contraction. Nonetheless, there’s little proof that sodium is linked to train induced muscle cramping. This might partly be as a result of the truth that muscle cramps are very troublesome to check. However present research have been removed from convincing and it’s seemingly that within the overwhelming majority of circumstances there are different causes for train induced cramping that aren’t sodium associated. Muscle cramps throughout train at the moment are believed to be a fancy phenomenon with many doable causes and contributing elements, which sadly are nonetheless not effectively understood. Having stated this, it’s clear that train induced muscle cramping happens extra in scorching circumstances particularly later in train when dehydration additionally happens. However it’s a stretch that the event of cramps is thus associated to lack of sodium, as the warmth itself, the fatigue of train and dehydration may all play a job in its growth. Clearly extra analysis must be finished earlier than we are able to say with confidence how train induced cramps are brought on, and what function, if any, diet has of their prevention.
Regulation of sodium within the physique
Our physique regulates the quantity of sodium within the physique. As soon as your physique takes in sufficient sodium, the kidneys eliminate the remaining in your urine, cleverly adjusting for any that has already been misplaced from sweating. The sodium focus within the blood is managed inside a really slim vary between 135 and 145 milliequivalents per liter (mmol/L). Hyponatremia, a probably life-threatening situation, happens when the sodium in your blood falls beneath 135 mmol/L (though signs will not be all the time current when this occurs). Kidneys play an important function in controlling the sodium focus in blood. In case your sodium focus within the blood is just too excessive or too low, it could imply that you’ve got an issue along with your kidneys, with hydration (perhaps too dehydrated or overhydrated), or one other medical situation. Inadequate sodium consumption is a extremely unlikely reason for low sodium within the blood (this will even be defined in additional element in future blogs).
So now we’ve mentioned what electrolytes are, what salt is and what sodium is, we are going to focus on the next questions within the subsequent blogs:
What function does sodium have throughout train?
How a lot sodium can we lose and does this trigger issues?
What’s the proof that sodium can assist efficiency?
Is sodium in sweat merely a mirrored image of the salt you could have in your eating regimen?
Sweat measuring instruments? Does it matter how exact you measure? What instruments do we’ve out there?
Electrolytes and muscle cramping what’s the proof?
How do you establish how a lot sodium you want?
1. Jeukendrup and Gleeson. Sport Vitamin. Human Kinetics Champaign IL 2018
2. Titze and Luft Kidney Worldwide 91(6): 1324–1335, 2017