The mineral potassium plays an essential role in many biological processes, including exercise and reaching peak physical performance. But if you have hyperkalemia, or high levels of potassium in the blood, that has its own challenges, especially when it comes to exercise.
Read on to see what happens to potassium levels when you exercise and for tips on how to exercise safely if you have hyperkalemia.
Potassium is an essential mineral and electrolyte that your body needs to survive. Healthy cell, nerve, and muscle function all rely on potassium.
Your body needs just the right amount of potassium in your blood for good health. Either too little (hypokalemia) or too much potassium (hyperkalemia) can interfere with nerve and muscle function, and can even be dangerous.
Normal blood potassium levels should fall in a range from about 3.6 to 5 millimoles per liter (mmol/L), though some labs use slightly different values.
When the kidneys are working properly, they flush surplus potassium out of the body through urine. Health conditions like kidney disease, heart disease, or diabetes can affect your kidney’s ability to regulate potassium levels in the body and increase your risk of hyperkalemia.
When blood potassium levels go well above the normal range, it may trigger sudden, severe symptoms like heart palpitations, shortness of breath, chest pain, nausea, or vomiting. This can be life threatening and requires emergency medical care.
If your heart is doing well and your potassium level is mildly elevated, you can take other measures to manage hyperkalemia.
When you exercise, your muscles lose potassium. This creates a substantial rise in blood potassium levels. For most people, the kidneys filter out the extra potassium fairly quickly, and potassium levels return to normal within a few minutes of rest.
When you have a health condition like hyperkalemia or heart disease, a spike in potassium can lead to a serious heart rhythm problem known as exercise-induced arrhythmia.
But regular exercise is important for a healthy lifestyle and may help you:
- maintain a healthy weight for your body size
- strengthen muscles
- increase flexibility
- boost mood and mental health
- improve overall health
Research suggests that physical conditioning or training may help reduce the increase in potassium levels during exercise.
High potassium can be dangerous, so talk with your doctor before starting a new exercise routine. They can assess your risk factors and recommend an exercise plan that’s safe for you. Some of these risk factors are:
- chronic versus acute hyperkalemia
- extent of kidney disease or heart damage
- other coexisting health conditions and medications
- age and overall health
With that in mind, here are a few tips to get started:
Generally speaking, it’s important to stay hydrated when you work out. Just be sure to follow your doctor’s guidelines for restricting fluids if you have kidney disease.
Whatever your previous level of activity, walking is a good choice. You can slowly increase the length and speed of your walks and get some fresh air in the process.
Move more throughout the day
When possible, add more movement to your day. For example, if you’re stationary most of the time, make it a point to move around for a few minutes every hour. Running errands? Choose stairs over elevators and park farther from entrances. Have a dog? Take more short walks and play breaks throughout the day.
Start your day with some stretching exercises to increase flexibility and get you going. Make sure you stretch before and after exercising, too.
Start small and build up gradually
Begin with a low intensity workout. If it seems like you’re overdoing it, don’t push yourself. Pull back and try again later. Increase your level of activity slowly.
With your doctor’s approval, you can add more rigorous activities to your workout routine over time.
Don’t push yourself too hard. Take time to rest and recover after exercising.
Time it right
Making time to exercise every day is ideal. If possible, try to schedule physical activity for earlier in the day. Exercising too close to bedtime can interfere with a good night’s sleep.
Work with your doctor
Keep up with doctor visits, take your medications as prescribed, and continue to manage your other health conditions. Talk with your doctor if you have any concerns about exercise.
Need a little extra motivation to keep moving? Try these tips:
- Use a fitness app or step counter to track your progress and remind you to move.
- Join a walking group or invite a friend to walk with you.
- Invest in a treadmill or exercise bike. You can use them while listening to music or watching your favorite show. They’re also a convenient backup to outdoor workouts in inclement weather.
- Choose a physical activity you enjoy, such as tennis, golf, gardening, or swimming, so you’re more likely to stick with it.
- Try something new, like yoga or tai chi.
- Set a small, achievable goal, then when you meet it, set another.
Potassium is actually a widely under consumed nutrient in the American diet. But if you have hyperkalemia, you might benefit from following a low potassium diet. According to the National Institutes of Health (NIH), the top dietary sources of potassium for adults in the United States are:
If you have hyperkalemia, work with your doctor or a dietitian to reduce your intake of these and other high potassium foods, such as:
- fruits, such as apricots, oranges, and bananas
- vegetables, such as squash, spinach, and broccoli
- legumes, such as lentils, soybeans, and kidney beans
- dairy, such as milk and yogurt
- animal proteins, such as chicken, salmon, and beef
While cutting down on these foods, be sure to get all the nutrients your body needs from other sources. If you’re on a low sodium diet, avoid salt substitutes that contain potassium. Some multivitamins may also contain potassium, so be sure to check the labels.
Your doctor or a dietitian can help you tailor a diet specific to your needs. Take all of your medications as prescribed, and be sure to tell your doctor if you take any dietary supplements.
Sleep is also important. Try to get 7 to 9 hours of sleep every night.
Work with your doctor to manage your other health conditions, especially those that are linked to hyperkalemia, such as kidney disease. Discuss any other medications you may be taking that can increase your risk for hyperkalemia, including commonly prescribed medications for heart disease or hypertension such as ACE inhibitors and many types of diuretics.
Report any symptoms like muscle fatigue. Seek emergency care if you experience a sudden onset of heart palpitations, chest pain, shortness of breath, nausea, or vomiting.
Your body needs potassium to function properly, but when levels become too high, it can be dangerous. There are several steps you can take to manage high potassium, from taking prescribed medications to following a low potassium diet.
Exercise is also important to your overall health and well-being. Physical activity can affect blood potassium levels, so speak with your doctor before you start exercising and while you’re engaging in an exercise routine if you have hyperkalemia.
When you get the green light, start with low intensity workouts and follow up with your doctor as recommended.