Chronic Kidney Disease:
Impact on Exercise and Fitness Ability
The kidneys filter most of your body’s fluids and, as a result, have impact across all
organs and systems of the body. Chronic kidney disease (CKD) occurs when the kidney’s
ability to function and filter properly starts to decrease, as measured by blood and urine
tests.
The primary functional measurement of the kidney is its glomerular filtration rate (GFR).
Normal results range from 90–120 milliliters (mL)/minute/1.73 square meters (m²).
Stages 1 and 2 CKD (60–90 mL/minute/1.73 m²) are represented by lower GFR rates and
slightly abnormal urine or blood tests, but usually do not result in significant symptoms.
Symptoms typically start at Stages 3 or 4 (15–60 mL/minute/1.73 m²), which reflects the
significant compromise of the kidneys’ ability to properly function.
The final stage of CKD, also known as end-stage renal disease (ESRD), occurs when the
kidneys can no longer adequately filter the body’s fluids (<15 mL/minute/1.73 m²).
ESRD typically results in the need for dialysis, which involves external machines playing
the role of the kidneys.
Symptoms and conditions progress based on the stage of CKD, and they can negatively
impact your ability to stay physically active.
Common side effects and diseases associated with kidney dysfunction include:
 Anemia (decreased red blood cell production and erythrocyte survival)
 Weakened bones (secondary hyperparathyroidism)
 Dyslipidemia
 Cardiovascular disease
 Diabetes
 Hypertension
Long-term ESRD and dialysis can lead to:
 Congestive heart failure
 Effusions
 Dysrhythmias
 Renal osteodystrophy (avulsion risk)
 Peritonitis (dialysis-related catheter infections)
The more progressed CKD becomes, the harder it is to fight, so the sooner you can do
something about it, the better!
Furthermore, CKD can lead to muscle wasting because of both increased catabolic
factors (inflammation, uremic myopathy, and metabolic acidosis) and decreased anabolic
factors (impaired protein synthesis associated with insulin or insulin growth factor
resistance). In other words, CKD causes your body to break down your muscle faster,
while also making it harder for your body to rebuild it. For individuals with ESRD,
hemodialysis is another factor that increases inflammation, leading to further muscle
breakdown.
Taken together, these issues lead to muscle weakness, fatigue, low functional capacity,
and as a result, lower rates of physical activity. Studies show that individuals with CKD
have functional capacities of only 50%–80%, compared to similar aged individuals
without CKD. People with ESRD or those on dialysis usually are at the low end of that
range (50%–60%).
This discrepancy is caused by a number of physiological changes that occur with CKD:
 Blunted heart rate response
 Lower cardiac output
 Excessive blood pressure increase
 Faster muscular fatigue from reduced oxygen capacity (anemia—fewer red blood cells)
and impaired oxygen extraction by muscles
 Lower blood flow increase for both submaximal and maximal bouts of exercise
 Impaired activation of motor neurons by the central nervous system (neuropathy)
 Advanced CKD or dialysis can potentially lead to altered energy metabolism and
electrolyte deficits, which lead to faster muscle fatigue and slower exercise recovery
rates
It sometimes is hard to feel motivated to stay active when staying active feels so hard!
Unfortunately, inactivity as a result of kidney failure, the side effects of dialysis, and
worsening comorbidities leads to further muscle breakdown, weakness, fatigue, and
reduced physical functioning. This negative spiral is associated with increased risk of
mortality. Yet, the most frail and incapacitated are most in need and benefit the most by
appropriate levels of physical activity.
In summary, CKD is a progressive disease that impacts many areas of the body and is
often associated with other chronic diseases. The symptoms and conditions of CKD can
make exercising more challenging. However, the sooner you can commit to becoming
more active, the more you can do to fight the progression of CKD and its related
conditions. Becoming more active at any stage of CKD is beneficial, even if you are on
dialysis. The key is creating a personal physical activity plan that is appropriate for your
needs and conditions.
References and recommended readings
Clyne N. Exercise training in chronic kidney disease. US Nephrology. 2010;5:15-17.
Johansen KL, Painter P. Exercise in individuals with CKD. Am J Kidney Dis.
2012;59(1):126-134.
Kosmadakis GC, Bevington A, Smith AC, et al. Physical exercise in patients with severe
kidney disease. Nephron Clin Pract. 2010;115(1);c7-c16.
MedlinePlus. Glomerular filtration rate. Available at:
http://www.nlm.nih.gov/medlineplus/ency/article/007305.htm. Accessed December 5,
2012.
Painter P. Exercise: A Guide for People on Dialysis. Available at:
http://www.lifeoptions.org/catalog/pdfs/booklets/exercise.pdf. Accessed December 5,
2012.
Painter PL, Krasnoff JB. ACSM’s Exercise Management for Persons with Chronic
Diseases and Disabilities. Champaign, IL: Human Kinetics; 2009.
Contributed by Jason Machowsky, MS, RD, CSCS, CDN
Review Date 12/12
R-0624