Why the Williams sisters and other stars are playing longer

It's difficult to overstate the impact of the Williams sisters on tennis. Now in their forties, both are back playing at the top level, after Serena, 44, joined 46-year-old Venus in appearances at the Queens tournament in London and the Berlin Open over the last week.

The pair have also been offered a wilcard doubles entry for Wimbledon a decade after they won the last of their six doubles titles at that particular Grand Slam. They have also won two US Open doubles titles, two in the French Open and four in the Australian Open. Between them they also have 30 Grand Slam singles titles; Serena has 23 of those. But her motivation for this comeback after four years out came a little closer to home.

"My daughter Olympia told me I should play with Venus. She's always right, so I was like 'damn,'" Serena said. "So I said 'You know, let's see if we can do it'."

Serena Williams has returned to professional tennis after four years out Image: Halil Sagirkaya/Anadolu/picture alliance

Venus Williams had returned to top level  tennis  this January, becoming the oldest woman to play singles at the Australian Open .

At 45, Williams, was handed a wildcard for the tournament and was 27 years older than the youngest player in the women's draw, fellow American Iva Jovic. After winning the first set, she fell 2-1 to Serbian player Olga Danilovic, in the first round. She's won one of her six singles matches since her comeback but is looking forward to reprising her prolific doubles partnership.

"It's incredible, the quality of her stroke is obviously there," Venus, who unlike Serena never formally retired from the sport, told British broadcaster TNT of her sister's return.

"She's, I think, a little bit of a natural, she’s got a pretty good record, she knows what she’s doing and she’s very tenacious, so I’m not worried about how she’s going to play even though I haven't seen her play, which is crazy."

Forty but not finished

While elite athletes competing into their 40s and beyond is not so unusual in less-physical sports, more elite athletes in more physically demanding sports appear to be able to sustain a career longer now than ever before.

LeBron James, 41, is still playing top-level basketball.  Cristiano Ronaldo, Luka Modric and Manuel Neuer are among eight over-40s at the ongoing football World Cup.  Former India cricket captain MS Dhoni was in the Chennai Super Kings squad in this year's Indian Premier League (IPL) at 44, though he didn't make an appearance.

"Population aging is not only increasing the average age of citizens but the average ages of elite sport participants, too," Dr. Rafal Chomik of the  UNSW Centre for Population Ageing Research (CEPAR) in Sydney, Australia, told DW.

"There are a number of likely explanations, including improvements in sports science, equipment innovation, and training regimes which are sport-specific, but there are also the wider societal trends that combine medical innovations and better health behaviors that shift all of us towards longer, healthier lives, including athletes."

CEPAR conducted a study of Olympic athlete ages at the Tokyo Games in 2021. It found that the average age of Olympians increased by 2 years from 25 to 27 between 1992 and 2021, with the median age up to 25 from 23. The trend continued at the Paris Games in 2024, with the average age just over 27 and the median age not far behind at 26.6.

Power fades first

But not all sports are made equal in this regard. The oldest competitor in Paris was Australian equestrian rider Mary Hanna at 70. That sport had an average competitor age of 39.5 in Paris — rhythmic gymnastics was the lowest at 20.44.

Another study, conducted over a 47-year period by the Karolinska Institutet in Sweden and released last month, found that "fitness and strength begin to decline as early as age 35" and that increased exercise cannot change the age of peak performance in a given sport.

How an 81-year-old sprinter chases a world record

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"We seem to lose power —  measured by jumping ability in our study — at an earlier age than endurance and strength," Maria Westerstahl, lead author of the study, told DW.

"One explanation could be that the explosive muscle cell type (Type II) appears most vulnerable to lack of exercise or to aging itself. However, we do not know why, so the exact reason requires further study," she continued.

"However, there is considerable room for change if you remain or become active. Aerobic capacity tracks the least, while muscular endurance tracks the most, meaning that aerobic capacity requires the most maintenance to preserve."

Winning gets harder with age

This goes a long way to explaining why the likes of Williams, James and Ronaldo are such outliers in the top echelons of sports where power matters, whereas sports like equestrian , bowls or darts see players in their 40s, 50s or even older compe…