Gerald Atwell has spent seven years making adults wear ankle monitors, and he would like the record to show that the hardest part was not the science. It was the Velcro.

Atwell is the physical-activity coordinator for a long-running Parkinson’s study out of the United States, the kind of position that exists in the acknowledgments section of a paper and nowhere else in public life. His job, from the first enrollment to the final data pull, was to fit accelerometers to the ankles of 294 adults with mild-to-moderate Parkinson’s disease, keep them wearing them, and count.

The study, published this fall in the journal Neurology, produced a result that made the rounds this week: the participants who exercised the most — more than eight hours a week — showed almost no average decline in memory and thinking over up to seven years, while also faring better on movement measures. The more they moved, the less their disease seemed to move them.

Scientists described the finding as a surprise. Atwell, reached at the research office where he has worked since the study’s first enrollment year, described it using the tone of a man watching a bus he has waited years for finally round the corner.

“Nobody in the building was shocked,” Atwell said. “We had been watching the trend since year two. What surprised people outside was that anyone was shocked. A gym teacher has been making this claim since approximately 1987 with no funding whatsoever.”

The study is the sort that can only be done slowly. Two cohorts of data collectors came and went. Atwell stayed. He learned which brand of strap held through a winter of indoor walking and which one participants quietly repurposed for their dog. He built, by his own accounting, a spreadsheet with more than a million rows, and he has never once shown it to another human being for fun.

His colleagues credit him with a compliance rate the principal investigators described in a grant renewal as “unreasonable.” Atwell considers the number a personal artifact. He once drove ninety minutes to retrieve an ankle monitor from a participant who had, with total sincerity, put the study device in a drawer “with the batteries.”

The finding now travels on its own. Doctors will tell patients to exercise. Patients, who have been walking since they were children, will be gratified to be asked. And Gerald Atwell, whose name appears near the end of the paper, will move on to the question that funds the next seven years of his life: whether walking faster is better than walking more.

The worst week, he said, was week two. Everyone forgot theirs in week two.