Staying Active Before Surgery May Halve the Risk of Postoperative Delirium

For millions of patients facing surgery each year, the operating room is only the beginning of a long and uncertain recovery. Among the most feared complications is one that many people have never heard of: postoperative delirium, a sudden and disorienting state of confusion that strikes roughly one in five surgical patients, most often older adults. Now, new research presented at the ANESTHESIOLOGY® 2026 annual meeting in San Diego suggests that one of the simplest and cheapest defenses against this condition may already be within reach of nearly every patient — regular physical activity in the weeks before surgery.

The study, led by researchers at the University of South Florida Morsani College of Medicine and Moffitt Cancer Center in Tampa, focused on patients undergoing cancer tumor removal surgery. Its central finding was striking: patients who reported walking or engaging in moderate or vigorous physical activity at least seven times per week had a 50 percent lower risk of developing postoperative delirium compared with their less active counterparts. In a field where interventions to protect the brain during and after surgery have remained elusive, a finding this strong — drawn from something as accessible as walking — has captured the attention of anesthesiologists and oncologists alike.

Postoperative delirium is far more than a fleeting moment of disorientation. It is a temporary but serious disturbance of attention, memory, and thinking that can leave patients unable to recognize where they are, why they are in a hospital, or who is caring for them. Episodes typically emerge in the hours or days following surgery, and their consequences ripple outward: longer hospital stays, delayed recovery, extended rehabilitation, and, most alarmingly, an increased risk of death. For older adults, whose brains are more vulnerable to the stress of anesthesia and surgical trauma, the condition represents one of the most common and costly complications of modern surgical care.

“People may realize that exercise before surgery can help their bodies recover more quickly, but our study also shows that it may protect the brain,” said Melody Haratian, B.S., lead author of the study and a medical student at the University of South Florida Morsani College of Medicine in Tampa. Her comment captures the conceptual shift that the research embodies. For decades, surgical preparation has centered on the body — building strength, optimizing nutrition, managing chronic disease. The idea that the brain, too, can be trained and fortified before the first incision is made marks an important evolution in how clinicians think about perioperative care.

The research team designed their investigation as a retrospective, matched, case-control study, a method that allows researchers to compare patients who experienced an outcome of interest with those who did not. The analysis included 258 patients who underwent cancer tumor removal surgery between 2024 and 2025. Of these, 64 developed postoperative delirium, while 194 did not. Rather than relying on subjective impressions, the researchers identified delirium cases using a positive Confusion Assessment Method test, a widely validated screening tool that helps clinicians detect delirium with reasonable reliability in busy hospital settings. The team also reviewed surgery reports to confirm the clinical context of each case.

One of the study’s most distinctive methodological choices was how it measured physical activity. Instead of counting the number of active days per week — the approach used in many exercise guidelines — the researchers tallied instances of physical activity per week. Participants self-reported how often they walked, engaged in moderate physical activity, or engaged in vigorous physical activity for at least 10 minutes at a time, and also estimated how many hours they spent sitting on a typical day. This frequency-based framing matters because it captures the cumulative rhythm of movement rather than treating exercise as an all-or-nothing habit confined to designated workout days.

The results painted a consistent picture. Patients who went on to develop delirium reported less walking, less moderate activity, less vigorous activity, and less total physical activity on average than those who remained clear-minded after surgery. They also reported more sitting time. When the researchers combined all forms of activity into a single weekly frequency, the pattern became statistically compelling: patients who reported a combined activity frequency of at least seven times per week were significantly less likely to experience postoperative delirium, with the risk reduced by half compared with less active patients. In practical terms, this means that spreading movement throughout the week — a morning walk one day, a brisk errand the next, a moderate workout later in the week — may offer meaningful protection for the brain.

“Preparing for surgery starts before the day of the operation,” said Jeffrey Huang, M.D., FASA, senior author of the study and professor of oncological science and senior member of anesthesiology at Moffitt Cancer Center in Tampa. “Patients should ask their care team about safe ways to stay active and whether a prehabilitation program could help them prepare for surgery and recover faster.” Huang’s advice reflects a growing movement in surgical medicine known as prehabilitation — the practice of preparing patients for surgery through exercise, nutrition, and other strategies in the weeks before the operation. The concept builds on accumulating evidence that patients who enter surgery in better physical condition tend to recover faster, experience fewer complications, and achieve better overall results. The new findings extend this framework to brain health, suggesting that prehabilitation may do more than strengthen muscles and cardiovascular reserves; it may also prime the nervous system to withstand the stress of anesthesia and surgical trauma.

The biological plausibility of this connection is supported by a growing body of research on exercise and the brain. Regular physical activity is known to enhance cerebral blood flow, support vascular health, reduce systemic inflammation, and promote neuroplasticity — the brain’s ability to adapt and reorganize. Delirium is thought to arise when the brain’s reserves are overwhelmed by perioperative stressors, including anesthesia, pain, inflammation, and metabolic disruption. A brain accustomed to the rhythmic stimulation of regular movement may simply have more resilience to draw upon when those stressors arrive. While the current study cannot establish causation — its retrospective, case-control design identifies associations rather than proving that activity directly prevents delirium — the strength and consistency of the association, combined with well-understood mechanisms, make the hypothesis biologically credible and clinically important.

The researchers themselves are careful to note that larger studies are needed before definitive clinical recommendations can be made. The study population was limited to cancer surgery patients at a single institution, and self-reported activity levels, while practical for large-scale research, introduce the possibility of recall bias. Nevertheless, the implications are hard to ignore. Postoperative delirium affects about 20 percent of surgical patients, and no pharmacological intervention has reliably prevented it. If something as simple, safe, and inexpensive as regular walking and moderate exercise in the weeks before surgery can meaningfully reduce that risk, the potential public health impact is enormous — particularly for the growing population of older adults undergoing major operations. For patients, the study authors say the takeaway is practical: people preparing for major surgery should talk with their healthcare team about safe ways to be active or participate in a prehabilitation program. The message from San Diego is clear — the road to a clear-minded recovery may begin long before the hospital, one step at a time.

Subject of Research: Postoperative delirium and preoperative physical activity in cancer surgery patients

Article Title: Could staying active before surgery help prevent postoperative delirium?

Article References: Could staying active before surgery help prevent postoperative delirium?. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: postoperative delirium, prehabilitation, cancer surgery, physical activity, anesthesiology, brain health, surgical recovery, ANESTHESIOLOGY 2026, staying, active, surgery, help