If you’re one of the 37 million adults in the U.S. with kidney disease, exercise can help you manage your condition. While exercise can’t “heal” kidney damage, it can make you stronger, both physically and mentally.
Physical activity is also a great way to help control the underlying conditions that may have led to your reduced kidney function.
“It’s all about your activity goals,” says UPMC nephrologist Hunter Huston, MD. “We don’t want to let disease or illness make you feel limited.”
Here is what to know about exercise for kidney disease.
What Causes Kidney Disease?
Your kidneys are busy organs. Their biggest job is clearing toxins from the bloodstream. They also help make red blood cells, keep bones strong, and help control blood pressure.
Doctors check your kidney function through a blood test. They are looking for how well your kidneys can clear creatinine, a waste product that comes from your muscles. “When creatinine can’t get out of the body, it’s a tip that your kidneys are struggling to keep up,” Dr. Huston says.
Doctors use a calculation called the glomerular filtration rate (GFR) to look at how well your kidneys are clearing creatinine. Ultimately, this is an estimate of your kidney function.
Above 90 is a good guideline for GFR, and roughly correlates with 90 to 100% kidney function. A number down into the 30s and 40s means greatly reduced kidney function and a later stage of kidney disease.
Your risk for kidney disease goes up with age. Kidney stones, auto-immune disorders, diabetes, and cancer treatment can also impact your kidneys.
“In adults, the two main causes of kidney disease are diabetes and high blood pressure,” Dr. Huston says, noting they represent the majority of patients he sees.
Lifestyle Changes and Exercise for Kidney Disease
“The food you eat becomes waste your kidneys have to get rid of,” Dr. Huston says. “That’s why, as people have increasing severity of kidney disease, diet becomes a huge component of their care.” (Learn more about the renal diet.)
The four key lifestyle changes that can help combat the underlying causes of kidney disease for most people are:
- Avoiding salt.
- Exercising.
- Keeping blood sugar in check.
- Losing weight.
Exercising gets triple-billing. It not only has its own set of benefits, it can also help you control blood sugar and lose weight.
“Some of the medicines that treat high blood pressure and diabetes have a risk of making your kidney function worse,” Dr. Huston says.
Regular exercise may help you reduce the number of daily pills you need for these conditions. This means less impact on your kidneys.
What Type of Exercise Is Best for People With Kidney Disease?
The type of exercise you do, and how much of it you do, depends entirely on your goals. If your goal is simply to live a healthy life, perhaps a vigorous running program wouldn’t be right for you. You might get what you need from walking and some simple strength training exercises.
“But if you are competitive and your goal is to get back to racing, we can find a way to do that safely,” Dr. Huston says. “There are unique risks we’ll need to manage.”
For example, he notes that there was a woman receiving dialysis who found a way to run the Boston Marathon some years back.
People who have kidney disease due to an auto-immune disorder, like lupus, will have unique considerations, too. Too much exercise can sometimes lead to a lupus flare-up.
The Importance of Hydration When Exercising with Kidney Disease
“Our thirst mechanism is our most sensitive trigger for how much fluid to drink,” Dr. Huston says. Hence, for most people, drinking to quench thirst is perfectly adequate as a guide for how much to water to drink.
But people with kidney disease have to be more careful, because they’re at risk for an acute kidney injury. Dehydration can cause this sudden worsening of kidney disease.
Dr. Huston tells his patients who have kidney disease to stop exercising if they become thirsty, since you’ve already lost fluid by the time you feel thirst. “Rehydrate and rest, and make sure you’re not sweating. Then you might be able to resume exercise,” he says.
He advises anyone with kidney disease to work with their nephrologist to figure out the right exercise and hydration plan. This can include a plan for replenishing electrolytes, as well as when to take blood pressure medication. (Blood pressure medication can increase the risk of dehydration while exercising.)
“We can always find the right hydration strategy,” he says.
Learn more about kidney disease care at UPMC.