Potassium is a buzzword at the gym recently, as more active people realize the mineral comes with a myriad of recovery benefits. Recent research found that a surprising amount of the world’s population don’t hit their recommended daily potassium intake. On top of that, exercise naturally alters your potassium—even a brisk walk is enough to shift your levels. So if you’re looking to make your recovery, and by association, your life, a lot easier, you'll want to fine-tune your intake.
Thankfully, for the average person, with the right foods and enough electrolytes, this is an easy box to tick. We spoke to experts to explain precisely what potassium can do for your recovery and why you should care.
“Potassium is a critical mineral and electrolyte that plays a vital role in maintaining fluid balance, nerve transmission, muscle contraction and cardiovascular health and function,” says Dr. Pupinder Ghatora, an award-winning pharmacist and co-founder of Ingenious. As it is not readily produced by our bodies, we must get it through diet, or supplementation.
Adult men over the age of 19 need roughly 3.4 grams of potassium daily. For context, a banana contains around 0.4 mg.
Potassium is regulated by our kidneys but a few things like illness (vomiting, diarrhea, some hormonal or kidney disorders), potassium-retaining medications, excessive sweating and simply not consuming enough can throw things off kilter. “Low potassium, also known as Hypokalemia, is typically when a blood potassium level is below ~3.5 [millimoles per liter],” says Dr. Ghatora. “This can lead to muscle weakness and cramps, muscle twitching and can even lead to paralysis or rhabdomyolysis in severe cases.”
The opposite can happen, too. If you have low kidney function, potassium will quickly build up in your bloodstream as it can't be easily passed through urine. “High levels of potassium, also known as Hyperkalemia, is typically described as levels above ~5.0 mmol/L," says Dr. Ghatora. "It can be caused by kidney disease, excessive potassium supplementation, particular medications (such as ACE inhibitors), severe muscle breakdown, or uncontrolled diabetes. It can cause muscle weakness, nerve tingling, slow or irregular heartbeat, ventricular arrhythmias and even cardiac arrest in severe cases.”
Like other bodily salts, you will lose potassium through sweat when you workout. However, during a particularly intense workout, your potassium levels will actually see a temporary spike. This is totally normal and just your muscles doing their job. “The effect is transient as potassium is then reabsorbed post-exercise, so blood serum may show an increase and then a decrease back to baseline following on from high-intensity exercise (assuming you have not lost more due to sweating),” says Dr. Ghatora. This undulation means you should keep your potassium levels in mind when you're working hard at the gym, whether through your diet or supplement.
Reduces muscle cramps
In very simple terms, potassium helps your muscles move properly. More specifically, it helps with muscle contraction. “I think of it as the spark that helps nerves communicate with muscle fibers,” says personal trainer Penny Weston. "Without enough potassium, your muscles can’t fire efficiently, which can make movements feel sluggish and reduce your strength and coordination.” This is because, as Dr. Ghatora says, when your muscles contract, “potassium shifts out of muscle cells while sodium moves in.” So, without enough of it in your system, this process ceases to work as effectively, which causes cramping. He adds that continuous low levels of potassium can lead to “muscle weakness, cramps, twitching, or even paralysis in severe cases”.
Supports nerve function
“Potassium is essential for generating and transmitting electrical impulses in nerves,” says Dr. Ghatora. “Correct potassium levels allow nerves to fire efficiently, which means that your coordination, reaction time and muscle activation are working appropriately. With those who exercise regularly, this can be critical to prevent injury."
Delays fatigue
Potassium can help with maintaining and restoring energy. “Potassium helps regulate fluid balance and nerve signals, which are key for maintaining energy throughout a workout,” says Weston. “When your potassium levels dip, your cells struggle to communicate effectively, and that's when you feel heavy mid-session. Staying topped up on potassium helps your body maintain endurance and keep going for longer, whether you’re running, cycling, or doing circuits.”
Better cardio and heart function
“A very important role that potassium plays is in cardiovascular function and maintaining regular heart rhythm,” says Dr. Ghatora. “Potassium regulates electrical conduction in cardiac muscle, and when you have abnormal levels, this can cause irregular rhythms.”
Dr. Ghatora recommends the following foods: “Lentils, beans, fruits and vegetables, potatoes or other starchy veg, dairy or whole grains.” Unless you suffer with kidney conditions, are someone who sweats excessively through exercise, or takes medication that might reduce potassium levels, Dr. Ghatora says that hitting your daily goal through diet is easy. Those who fall into any of the former categories may want to consider supplementation.
Let's just preface by saying you should always check with your doctor before testing new supplements—particularly in this case where dietary fuel is the optimal way to consume potassium. “Potassium supplementation is a good idea when you have low levels confirmed by blood tests, Dr. Ghatora says. "However, there are certain people who should avoid them, unless, of course, told otherwise by their healthcare provider.” This includes and is not limited to, people with kidney disease, heart rhythm disorders or people over the age of 65.
This story originally appeared in British GQ.