Why Staying Physically Active Matters for Cancer Patients
Many cancer patients undergoing chemotherapy report experiencing “chemobrain,” a term commonly used to describe cancer-related cognitive impairment (CRCI). These symptoms can include difficulty concentrating, memory problems, slower thinking, and mental fatigue. Studies suggest that as many as 75% of cancer patients experience some level of cognitive impairment during treatment, and for some individuals these symptoms can persist for years after therapy ends.
CRCI is not just a minor inconvenience. Cognitive problems can interfere with daily life, making it harder for patients to manage medications, maintain employment, perform household tasks, or even drive safely. Unfortunately, there are currently no widely accepted medical treatments for chemotherapy-related cognitive impairment, leaving many patients searching for strategies that can help protect their brain function during treatment.
A new nationwide study offers encouraging news: exercise may help reduce cognitive decline during chemotherapy.
A Landmark Exercise Study in Cancer Patients
Researchers conducted a large multicenter Phase III randomized clinical trial involving 687 cancer patients treated at 20 community oncology practices across the United States. The study examined whether a structured exercise program could reduce cognitive impairment and mental fatigue during chemotherapy.
Participants were randomly assigned to either usual care or a structured exercise program called EXCAP (Exercise for Cancer Patients). The EXCAP program was designed to be practical and accessible. It included:
• Daily walking at low-to-moderate intensity
• Resistance band exercises performed several times per week
• A home-based program lasting six weeks, beginning at the start of chemotherapy
Importantly, patients received individualized exercise guidance and simple tools such as pedometers and resistance bands to help them stay active.
Exercise Reduced Cognitive Decline and Fatigue
The results were striking. Patients who followed the exercise program experienced less cognitive decline compared with patients who did not exercise, particularly among those receiving chemotherapy every two weeks. Participants in the exercise group also reported less mental fatigue, another common and debilitating symptom during treatment.
Researchers also discovered an important biological explanation. Exercise appeared to improve the body’s inflammatory and immune response, which is believed to play a role in chemotherapy-related cognitive impairment. A healthier balance of inflammatory markers was associated with better cognitive function during treatment.
Exercise Prevents the “Activity Crash” During Chemotherapy
Another key finding from the study highlights a challenge many cancer patients face. When patients were not given a structured exercise plan, their physical activity dropped dramatically during chemotherapy. On average, these patients reduced their walking by more than 50%, falling to fewer than 2,000 steps per day—less than one mile of walking.
In contrast, patients who followed the exercise program maintained their activity levels and incorporated strength training, helping preserve both physical and cognitive health during treatment.
What This Means for Cancer Survivors
The message from this research is clear: exercise can be a powerful tool during cancer treatment.
Even modest physical activity—such as walking and simple resistance exercises—may help:
• Protect brain function
• Reduce mental fatigue
• Maintain physical strength
• Improve quality of life during chemotherapy
Exercise is not a replacement for cancer treatment. However, it may be one of the most important supportive therapies available to patients undergoing chemotherapy.
A CancerFitness.org Call to Action
If you are undergoing cancer treatment, consider discussing physical activity with your oncology team. Many patients can safely begin low-to-moderate intensity exercise programs, even during chemotherapy.
At CancerFitness.org, we encourage cancer patients and survivors to view exercise as part of their survivorship strategy—not just for fitness, but for protecting the brain, body, and long-term health.
Start small. Walk daily if possible. Add light resistance exercises. Most importantly, stay consistent.
Your brain—and your body—may benefit more than you realize.
Reference: Effects of Exercise on Cognitive Impairmentin Patients Receiving Chemotherapy:A Multicenter Phase III Randomized ControlledTrial. Karen M. Mustian, PhD, MPH; Po-Ju Lin, PhD, MPH, RD; Alisha Chakrabarti, PhD; Lindsey J. Mattick, PhD, MPH; et al. J Natl Compr Canc Netw 2026;24(3):91–99 doi:10.6004/jnccn.2025.7118.
