Most of us think of surgery as something you prepare for the night before. A packed bag, a fast after midnight, a ride to the hospital. The hard work, we assume, starts in the recovery room.
A new study points in a different direction. Cancer surgery patients who exercised at least seven times a week before their operation had a 50 percent lower risk of developing postoperative delirium.
The findings came from research presented at the American Society of Anesthesiologists ANESTHESIOLOGY 2026 annual meeting in San Diego.
Delirium is one of the most common complications after major surgery, yet many patients have never heard of it. It brings sudden confusion, trouble focusing and memory lapses in the hours or days after an operation.
Also read: Think more sleep is better? New research suggests otherwise
About 20 percent of surgical patients experience it. The condition is especially common in older adults.
What the researchers actually found
The team from Moffitt Cancer Center and the University of South Florida looked back at records from 258 cancer surgery patients treated in 2024 and 2025. Sixty-four had developed delirium after their operation, and 194 had not.
Researchers measured how often each patient walked and did moderate or vigorous activity in a week, rather than just counting active days. They used the Confusion Assessment Method, a standard screening tool, to identify delirium cases.
Patients who hit at least seven exercise sessions a week had half the delirium risk of less active patients. The study is observational, so it cannot prove that exercise itself was what protected the brain.
Also read: 'Forever chemicals' are everywhere: Here's what they could do to your body
Lead author Melody Haratian said patients often know pre-surgery exercise speeds physical recovery, but the new data suggests it may also protect the brain.
The direction fits a wider body of work on prehabilitation, meaning preparing the body for surgery through exercise, nutrition and other steps.
Why delirium matters more than many patients know
Postoperative delirium is more than a passing fog. A 2024 review in the Journal of Neurosurgical Anesthesiology called it one of the most prevalent complications in older surgical patients. Rates reach up to 65 percent in some populations.
The condition is linked to longer hospital stays, higher death rates and faster long-term cognitive decline. For some patients, an episode of delirium is tied to a measurable rise in the risk of later dementia.
Also read: Older adults ate blueberries daily for three months, and something quietly shifted in the gut
What this means before your surgery
Senior author Jeffrey Huang said patients should ask their care team about safe ways to stay active in the weeks before an operation. A formal prehabilitation program may also be worth asking about.
For many patients, that does not require a gym. Walking around the neighborhood, taking the stairs or using a stationary bike at a brisk pace can count, as long as the activity is comfortable and cleared by a doctor.
Anyone with a planned surgery coming up can ask their surgeon or anesthesiologist which activities are safe during the weeks before the procedure.
Also read: Experts reveal: Why honey is particularly beneficial during the colder months
Also read: The unseen damage a lack of deep sleep does to your synapses
This article is made and published by Jesper Bengtson, who may have used AI in the preparation.