A few years ago, Sens. Charles E. Grassley (R-Iowa) and Patrick J. Leahy (D-Vt.) established unusual benchmarks for deciding whether to run for reelection in 2022, potential six-year terms that would end with Grassley in his mid-90s and Leahy in his late 80s.

“If I can run three miles four times a week, I’ll be running for reelection,” Grassley, now 87, said at the time.

Leahy, in non-pandemic times, celebrates his birthday by scuba diving, first swimming down to the depth of his new age, doing a somersault underwater. “If I reach the point that I can’t go scuba diving and do my somersaults, that will be one clear indication,” Leahy, now 80, said in late 2017.

The longest-serving Republican and Democrat in the Senate are part of a large bloc of octogenarians who continue to serve well past the average retirement age of a typical American worker.

Today, seven senators are at least 80 years old, the second-largest number of 80-somethings to ever serve together, according to records kept by the Senate Historical Office. The largest group came in 2018, when eight senators had eclipsed their 80th birthday, which nearly doubled the previous record for octogenarians serving in the Senate.

Two of these senators, Lamar Alexander (R-Tenn.) and Pat Roberts (R-Kan.), looked at running for another term this year and opted to retire.

Still, Sen. Bernie Sanders (I-Vt.) will turn 80 in September, and a few months after that, Majority Leader Mitch McConnell (R-Ky.) will crest the eight-decade mark, bringing the membership of the over-80 club back up to seven if everyone else remains in good health.

When Alexander, 80, decided in 2018 to retire, he publicly said that he did not want to make a mistake and “stay too long.”

Roberts, 84, acknowledged Friday that he had a long conversation with his wife of 51 years about his future. “So Franki and I talked about it, and I thought, obviously, at the level of maturity that I had reached, it was time,” he said.

The age question has taken on fresh relevance in recent weeks as the oldest senator, Dianne Feinstein, 87, just announced that she would step down as the top Democrat on the Judiciary Committee.

The Californian moved aside, in part, because of liberal criticism that she was too acquiescent to the GOP chairman, Sen. Lindsey O. Graham (R-S.C.), but questions have lingered about her capabilities for several years. And those spilled into print on Thursday with a story from The New Yorker’s Jane Mayer, in which former aides lamented her decision to run for another term in 2018, at the age of 85, when she could have instead “gone out on top.”

That followed the 2018 decision by Thad Cochran (R-Miss.), a nearly 40-year veteran of the Senate, to step aside running the powerful Appropriations Committee amid failing health. He retired with more than 2½ years left on a term he had won in 2014 just before turning 77.

Now Grassley, Leahy and Sen. Richard C. Shelby (R-Ala.) face the same questions that Alexander, Roberts, Feinstein and Cochran all answered in different fashion.

Both Grassley and Leahy seem poised to dive into this eight-year commitment, two years to run for another term and six more if reelected.

Grassley would be 95 at the end of this potential term in 2028, which would make him the oldest person in the Senate since Strom Thurmond turned 100 in 2002 just before retiring.

Nonetheless, Republicans are openly courting Grassley.

“I want him to run again. So I’ve called everybody bugging them about running again,” Sen. Rick Scott (R-Fla.), the incoming chairman of the National Republican Senatorial Committee, said Friday.

Grassley plans to make up his mind by the middle of next year. “Many of my colleagues have encouraged me to run again. I love my job working every day on behalf of Iowans. That’s why I get up at 4 a.m. every day and am the first person in the office, ready to work, and why I hold 99 county meetings across Iowa every year. I’ve got a lot of work yet to get done for the people of Iowa,” Grassley said in a statement, leaning into continued service.

His office pointed to an interview with Iowa media in which he explained that he ran 13 straight days during his recent asymptomatic bout of covid-19, although his morning runs are now just 2 miles.

Leahy plans to have a discussion with his wife and make a final decision in November, part of his long-standing tradition to decide one year before he faces voters.

“He hasn’t had a chance to test his SCUBA skills during the pandemic, but he and Marcelle hope to have a chance to do that before next November,” said David Carle, his spokesman.

Shelby, 86, seems less inclined to make another run. Once considered the Senate’s most voracious fundraiser, Shelby has collected just $261,000 for his campaign account since 2017.

On Friday, he said he would decide in late January. “I think everybody has to evaluate their own situation, what they want to do, how long they want to say, what they do when they’re here, what their opportunities are. And I’ll say, there’s a season in everything,” he said.

Shelby, the Appropriations Committee chairman, has had a front-row seat for senators whose final years were marked by a bad decline. Cochran had to resign midterm, and two of the previous chairs, Robert C. Byrd (D-W.Va.) and Daniel K. Inouye (D-Hawaii), died while in office in 2010 and 2012, respectively.

The aging Senate, to some extent, is modeling the broader society. On Jan. 20, Democrat Joe Biden, 78, will be sworn in as the nation’s 46th president, succeeding President Trump, age 74. According to the Bureau of Labor Statistics, workers 55 and older represented 12.7 percent of the entire U.S. workforce in 1999; by last year, that number had nearly doubled to 23.4 percent.

Then again, that study did not measure workers who were 80 and older.

Every senator in his or her 80s sits atop one of the powerful legislative committees, which means many have a collection of aides and former aides working on K Street whose livelihoods are somewhat dependent on another Senate term.

So sometimes the advice they receive might come with a level of self-interest.

Roberts said he felt comfortable because, as chairman of the Agriculture Committee, he had passed the most recent farm bill and took care of some key things for his state.

“There’s still some things I want to get done,” he said, pausing, and then making clear that there would always be something not finished. “That could go on forever. So it was time.”

Elderly senators said this decision is so personal that they do not really discuss it with one another. After announcing his decision two years ago, Alexander said that he only gave McConnell, a friend of 50 years, a slight hint what he was thinking.

Roberts said none of the 80-somethings facing the 2022 reelection question have asked him how he decided to retire.

“They ask me advice, on other things, but that one is a pretty private decision,” he said.