Researchers wanted to know if eating well and exercising during chemotherapy could help breast cancer patients feel better. They studied 173 women with breast cancer—some got help with nutrition and exercise for a year, while others received regular care. Both groups struggled with fatigue, weakness, and mood changes during treatment, but surprisingly, the exercise and nutrition group didn’t feel significantly better than the regular care group. However, everyone’s quality of life improved after treatment ended. This study shows that while healthy habits are important, we still need to find better ways to help patients feel good during chemotherapy itself.
The Quick Take
- What they studied: Whether eating healthy and exercising during chemotherapy helps breast cancer patients feel better physically and mentally compared to regular care
- Who participated: 173 women with early-stage breast cancer (average age 53), about half with stage I cancer, who were starting chemotherapy treatment
- Key finding: Both groups experienced similar declines in energy, physical strength, and mood during chemotherapy. The nutrition and exercise group did not recover faster or feel significantly better than the regular care group during treatment, though both groups improved after chemotherapy ended.
- What it means for you: If you’re undergoing chemotherapy, eating well and exercising may not prevent the tough side effects during treatment, but they’re still worth doing for overall health. Don’t expect them to be a magic fix during active treatment, but recovery afterward appears similar whether you follow these habits or not.
The Research Details
This was a randomized controlled trial, which is considered one of the strongest types of research. Researchers randomly assigned 173 women with breast cancer into two groups: one group received a year-long program focused on nutrition counseling and exercise guidance (87 women), while the other group received standard medical care without the special program (86 women). The women answered detailed questionnaires about their physical abilities, energy levels, mood, thinking skills, and overall well-being at four different time points: when they started treatment, right after chemotherapy finished, one year later, and two years later.
The researchers used standardized measurement tools called PROMIS scales, which are trusted questionnaires that ask patients to rate their own health and well-being. These same tools are used to measure health in the general U.S. population, so researchers could compare how the cancer patients were doing compared to healthy people. This approach allowed them to track whether the intervention group’s quality of life stayed better than the usual care group throughout the study.
This research design is important because it directly compares two groups of similar people treated differently, which helps prove whether the intervention actually caused any differences. By measuring patients at multiple time points, researchers could see not just the final outcome, but how people changed over time during and after treatment. This matters because it shows us what really happens to patients’ well-being during the difficult chemotherapy period, not just afterward.
This study has several strengths: it randomly assigned participants to groups (reducing bias), it followed people for two years (giving a complete picture), it used validated measurement tools (trusted questionnaires), and it had a reasonable number of participants. However, the study was published in 2025 and represents current research standards. The main limitation is that both groups knew they were in a study, which might have influenced their behavior. Additionally, the study population was mostly white and educated, so results might not apply equally to all women with breast cancer.
What the Results Show
During chemotherapy, both groups experienced similar declines in quality of life. Physical function decreased by about 5 points in both groups, fatigue increased by 5-6 points, and the ability to do social activities dropped by 5-7 points. Mental health scores also declined by about 10-11 points during treatment. Interestingly, anxiety actually improved during chemotherapy in both groups, dropping by about 4-5 points.
The key finding was that the nutrition and exercise intervention group did not experience better outcomes than the usual care group during chemotherapy. The differences between groups were very small and not statistically significant, meaning they could have happened by chance. This was surprising to researchers because they expected the intervention group to maintain better quality of life during treatment.
After chemotherapy ended, both groups recovered remarkably well. By one year after treatment started, most quality of life scores returned to the levels they were at before treatment began. These improvements stayed stable through the two-year mark. The only exception was anxiety, which remained improved compared to baseline levels.
Cognitive function (thinking and memory) declined slightly during chemotherapy in both groups (by about 4-5 points), but this also recovered by one year. Social role function—the ability to do work and social activities—showed one of the larger declines during treatment (5-7 points) but also recovered well afterward. Global physical and mental health scores showed the largest declines during chemotherapy (about 10-11 points) but returned to baseline by one year. The fact that anxiety improved during treatment in both groups is noteworthy and suggests that patients may have felt relief or hope once active treatment began.
This study fills an important gap in cancer research. While previous studies showed that nutrition and exercise help cancer patients feel better after treatment ends, very few studies had looked at whether these interventions help during chemotherapy itself. This research confirms that the post-treatment benefits are real, but it suggests that the mechanisms helping patients recover after treatment may be different from what helps them during treatment. The finding that both groups recovered similarly suggests that the body’s natural healing process after chemotherapy may be more important than lifestyle interventions during the treatment phase.
The study has several important limitations. First, participants knew they were in a study, which might have caused the usual care group to also improve their nutrition and exercise habits on their own. Second, the study population was mostly white, college-educated women, so results might not apply equally to women of other races or educational backgrounds. Third, the study couldn’t determine which specific aspects of the intervention (nutrition advice, exercise, or both) might have been most helpful. Fourth, the researchers couldn’t measure whether participants actually followed the nutrition and exercise recommendations, so we don’t know if lack of benefit was due to the intervention itself or poor adherence. Finally, the study was relatively small, so larger studies might find different results.
The Bottom Line
Based on this research, we can say with moderate confidence that eating well and exercising during chemotherapy won’t prevent the side effects that most patients experience. However, these habits are still recommended because they support overall health and may help with recovery after treatment. The evidence suggests that patients should focus on managing chemotherapy side effects with their medical team during treatment, and then use nutrition and exercise to support recovery afterward. High confidence: Everyone should maintain basic nutrition and physical activity during chemotherapy as tolerated. Moderate confidence: Don’t expect these habits to prevent chemotherapy side effects, but they may help with overall recovery.
This research is most relevant to women with early-stage breast cancer (stages I-III) who are about to start chemotherapy. It’s also important for their doctors, nurses, and family members who want to know realistic expectations about quality of life during treatment. Women with other types of cancer or more advanced cancer should talk to their doctors about whether these findings apply to them. This research is less relevant to people who have already finished chemotherapy, though the recovery patterns described might still be helpful to know.
Most patients experienced the worst quality of life during chemotherapy itself, with declines in energy, physical strength, and mood. These effects typically peaked at the end of chemotherapy. Recovery began immediately after treatment ended, with most patients returning to their pre-treatment quality of life within about one year. Full stabilization of improvements occurred by two years. Realistic expectations: expect 3-6 months of significant side effects during chemotherapy, gradual improvement over the next 6 months, and return to baseline by one year.
Want to Apply This Research?
- Track daily energy levels (1-10 scale) and ability to do normal activities (work, social events, exercise) during and after chemotherapy. This allows users to see their personal recovery pattern and compare it to the study findings. Record weekly: fatigue level, physical activity minutes completed, mood rating, and ability to perform usual roles.
- Set realistic, flexible goals for nutrition and exercise that adjust based on how you feel each day. During chemotherapy, the goal should be ‘do what you can’ rather than strict targets. After chemotherapy ends, gradually increase exercise duration and intensity. Use the app to celebrate small wins like ‘ate a healthy meal today’ or ’took a 10-minute walk’ rather than focusing on preventing side effects.
- Create a personal recovery timeline in the app showing expected quality of life changes. Track the same measures (energy, mood, physical function) at the same time points as the study (at treatment start, end, 1 year, and 2 years) to see how your recovery compares to the study group. This helps set realistic expectations and identify when recovery is on track.
This research describes what happened in one study of 173 women with early-stage breast cancer. Individual experiences vary greatly, and your own quality of life during and after chemotherapy may be different. This information is not medical advice and should not replace conversations with your cancer care team. Before starting any new exercise or nutrition program during chemotherapy, discuss it with your oncologist or medical team to ensure it’s safe for your specific situation. If you’re experiencing severe side effects from chemotherapy, contact your healthcare provider immediately rather than relying on lifestyle changes alone.