Adrian Davis helps his wife, Brenda, into the living room. (Jonathan Newton/The Washington Post)

“Excuse me,” Adrian Davis said to me, his voice graveled by a lifetime in the boxing ring, exhorting local fighters such as Hasim Rahman, William Joppy and Sharmba Mitchell to become world champions.

He popped up from the black leather couch in his family room, his 75-year-old body still sturdy from a push-ups regimen every morning, and walked a couple of steps to his wife of 53 years, Brenda.

She was seated in a black wheelchair.

“You okay, baby?” the pillar of D.C.-area boxing for half a century asked her softly.

Brenda groaned. She clenched her jaw. She rocked forward. She turned her head side to side. Her light brown eyes glanced at everything but appeared to see nothing.

Mr. Davis, as I came to know him as the neighbor of a childhood friend, gently pulled up the shoulders of his wife’s long-sleeve gray shirt that had slipped down her arms. He carefully slid her an inch or two back in her wheelchair.

A picture of two of Adrian Davis’s children, Victor, left, and Demetrius, in their fighting poses. (Jonathan Newton/The Washington Post)

It reminded me of him tending to one of his charges in the corner, but with tenderness.

Brenda is Adrian Davis’s greatest fighter. Her opponent is Alzheimer’s, and it’s wearing down her and her husband. For the past seven, eight, nine years — Mr. Davis isn’t sure — he has been one of the more than 15 million Alzheimer’s or dementia caregivers in the country.

“I’m so sad for my wife,” Mr. Davis said, returning to sit on the couch in front of Brenda, his hands resting in his lap clasped together by fingers thickened from 42 pro bouts of his own. “She did everything.”

She became the first female fight judge in the area. She presided for years over the Potomac Valley Boxing Association, a nonprofit for amateur boxers in D.C. and Maryland’s Prince George’s and Montgomery counties.

Now, Mr. Davis does everything for his soul mate, who managed Round One Boxing in Hyattsville, the gym he lost some years ago. Who ferried boxers to and from weigh-ins and fights in the couple’s car. Who washed their clothes. Who cared for some contenders such as Mitchell in their house as if they were their sons.

Adrian Davis holds the hand of his wife, Brenda, as they watch television. (Jonathan Newton/The Washington Post)

I reached out to Mitchell, who went on to win the WBA light welterweight title in 1998. I didn’t hear back. Mr. Davis said he hasn’t heard back from any of his many fighters over the years, now that he could use their help. One person established a GoFundMe campaign for Mr. Davis. Its goal was $35,000; it raised $630. Two other GoFundMe campaigns that people established for Brenda are dormant.

Mr. Davis feeds Brenda. He bathes Brenda. He changes Brenda’s clothes. In the morning, he lifts her out of a hospital bed in a now musty study on the first floor of their Bowie home and into her wheelchair. In the evening, he returns her to the hospital bed.

One of Mr. Davis’s two sons, Demetrius, a former light heavyweight who won just 20 of 50 pro fights between 1987 and 2010, can’t help. He’s serving time in Hagerstown for armed robbery. Mr. Davis’s other son, Victor, lives with Mr. Davis and lends a helping hand, too. But after a pro welterweight career from the mid-1980s to mid-’90s, in which he compiled a 24-12-1 record, he is a struggling trainer without much largesse, either. The lone daughter, Veeda, who was born two weeks after Mr. Davis’s last fight Dec. 5, 1972, well, Mr. Davis didn’t want to talk about her assistance.

Brenda moaned.

“Baby, what’s the matter?” Mr. Davis asked.

Brenda didn’t seem to hear or see him. He retrieved a purple plastic cup with water and attempted to place it in her left hand.

“Owwwww!” Brenda yelped, rocking forward, her face contorted.

“I’m sorry, I’m sorry,” Mr. Davis exclaimed. “Did I hit your hand?”

Brenda gripped the cup and took a sip.

“She never said no to me,” Mr. Davis said. “I owe her.”

Mr. Davis realized something was wrong with Brenda after a series of car accidents starting seven or eight years ago. Mr. Davis said she didn’t realize the accidents occurred. Then she started wandering out of the house. A neighbor would call for someone to retrieve her. Mr. Davis and Brenda went to a doctor. The doctor diagnosed her as suffering from on-set dementia.

After Mr. Davis stopped fighting, he started his training business. It got going about as well as a trainer could hope.

“$500,000 from Hasim Rahman, $320,000 from Sugar Ray Leonard, $175,000 from ‘Razor’ Ruddock,” Mr. Davis recalled in rapid fire with his encyclopedic memory.

He and Brenda bought their house in Bowie in 1990 with his earnings.

But Mr. Davis can’t make that kind of money anymore. He’s dedicated to Brenda as he vowed Oct. 2, 1965, “. . . to have and to hold, from this day forward, for better, for worse, for richer, for poorer, in sickness . . .”

He was training Accokeek heavyweight Jarrett Hurd as recently as last year. He was not in his corner May 11 at EagleBank Arena on George Mason University’s campus when Hurd suffered his first defeat and lost his title . For whatever reasons, Hurd’s handlers went with another trainer.

It may have been because Mr. Davis turned down going to Las Vegas for a Hurd fight in April of last year. Maybe Hurd’s handlers didn’t think Mr. Davis was committed to Hurd. He’s certainly committed to Brenda.

“I had to turn down a trip with him to Las Vegas because I didn’t want to leave my wife,” Mr. Davis said. “I thought maybe they should bring in a nurse because, you know, Victor, this being his mother, he don’t really want to change her, you know, wipe her down. I do that all the time, so I couldn’t go. So I turned down the trip.

“My insurance only goes so far,” Mr. Davis explained. “My insurance don’t extend to a nurse coming in here five or six times a week. I don’t have that. It’s me and my son Victor.”

In most any other employment, there likely would be something to rely on. Maybe long-term health care. A 401(k) plan or IRA to dip into. Something. But in the fight game, you’re left on your own after it grinds you up. Once you have no more blood to spill for the sport, it is done with you. Mr. Davis hung up his gloves after losing an eye. His son Demetrius lost an eye, too.

But Mr. Davis can’t afford to be finished in the game. This is all he has ever done. It’s all his wife would remember, if she could.

Brenda squirmed in her wheelchair and moaned.

“If I can make one more purse . . .” Mr. Davis said.

Kevin B. Blackistone, ESPN panelist and visiting professor at the Philip Merrill College of Journalism at the University of Maryland, writes sports commentary for The Washington Post.