Fitness is more important than weight loss for reducing the risk of kidney disease, according to a study.

Fitness is more important than weight loss for reducing the risk of kidney disease, according to a study.

The Importance of Physical Fitness in Preventing Chronic Kidney Disease


Oct. 2, 2023 – Do you need a better reason to work out than just losing weight? Well, here’s one: higher physical fitness and maintaining body weight have been found to lower the risk of chronic kidney disease in adults with obesity. In a fascinating study published recently in Obesity, researchers discovered that losing weight alone did not decrease the risk, emphasizing the significance of preventive measures.

Obesity is a well-established risk factor for kidney disease, which is one of the leading causes of death in the United States. Extra body fat leads to hormonal changes that increase body fluid volume, raise blood pressure, and promote insulin resistance. Consequently, your kidneys have to work harder to filter your blood, leading to damage and scarring. “The kidneys can only compensate so much before there is permanent damage,” explains Dr. Meera Harhay, an epidemiologist and a kidney transplant expert from Drexel University in Philadelphia.

Dr. Harhay and her colleagues conducted their study using data from the Multi-Ethnic Study of Atherosclerosis, an initiative by the National Institutes of Health. The study followed 6,814 middle-aged adults in six U.S. cities, monitoring their weight and other health measures over a span of 10 years. Among the 1,208 obese adults without kidney disease or diabetes at the beginning of the study, the researchers found that for every 11 pounds gained, the risk of developing kidney disease increased by 34%. Surprisingly, losing weight did not reduce the risk, implying that preventing weight gain is more important than weight loss itself.

To measure fitness levels, the researchers used the participants’ self-reported walking pace. They found that individuals who walked slower than 2 miles per hour were 57% more likely to develop kidney disease compared to faster walkers. This suggests that regular exercise, even in the presence of kidney damage, may help the body withstand the detrimental effects. The researchers believe that the anti-inflammatory effects of exercise and improved cardiovascular health contribute to this protective effect. However, they acknowledge that more research is needed to fully understand the mechanisms at play.

What makes this study truly intriguing is its departure from the conventional focus solely on body weight in obesity research. There has been a growing trend towards exploring other factors that may explain the link between obesity and disease. According to Matthew Ahmadi, a postdoctoral researcher at the University of Sydney in Australia, researchers have been investigating whether “fitness” or “fatness,” or a balanced combination of both, is the primary driver of longevity and disease risk.

In a 2022 study co-authored by Ahmadi, individuals who walked at a faster pace had a 36% lower risk of dying during the study period (7 years) than those who walked more slowly. Another study from the University of Arizona in 2021 found that starting a regular exercise routine, regardless of weight loss, counteracted the risk of early death associated with a high body mass index.

It’s important to note that intense workouts may pose complications for patients with existing kidney damage. Kidney disease is often accompanied by muscle loss (sarcopenia) and weakened muscle strength (dynapenia). For these individuals, resistance training can be a suitable option. Recent research even suggests that resistance training may be more effective in improving walking speed for patients with sarcopenia compared to programs that incorporate different types of training.

To ensure safety and effectiveness, individuals with kidney disease should consult their physicians about their exercise goals. Dr. Harhay, for instance, plans to explore strategies to help people with obesity and kidney disease lose weight while maintaining muscle mass.

In conclusion, this study sheds light on the importance of physical fitness and weight maintenance in preventing chronic kidney disease among adults with obesity. It highlights the need for a holistic approach to managing obesity-related health risks, moving beyond a narrow focus on body weight alone. Regular exercise, tailored to individual circumstances, holds the potential to mitigate the detrimental effects of obesity on kidney health. So, let’s get moving and protect our kidneys!