After a routine health check raised several red flags, 40-something software manager Cao Yu knew he needed to change his lifestyle. Two years ago, he finished his first triathlon, an ultra-tough endurance sport that combines swimming, cycling, and running.

Now, like many middle-aged Chinese, he’s hooked.

No matter how busy life gets, Cao always finds time to train and participate in competitions, even taking his family along on race days.

“The atmosphere’s great,” he said. “It’s not the competitive feeling of the group competitions you see on TV, like the Olympics. It’s more about enthusiasts participating together and enjoying the process.”

China is today home to more than 57,200 registered triathletes, according to the state-backed China Triathlon Sports Association. Some 28,304 of these have signed up in the past five years, with over-35s accounting for nearly 40%.

In May, Cao took part in the Jinhai Lake race in Beijing, where he estimates that most participants were aged 35 to 45. He eventually finished fifth, one place behind a 62-year-old man.

The first modern triathlon is considered to have taken place in the United States in the mid-1970s, when 46 athletes competed in a race in California that consisted of running just over 8.5 kilometers, cycling 8 kilometers, and then swimming about 550 meters. While the format remains the same, distances now vary depending on the organizing body.

In recent years, despite its physical intensity, the sport has boomed among older sports enthusiasts in China.

Jackson Liu, the head of Challenge Xiamen, part of the global Challenge Family triathlon event series, said 1,800 people have registered for November’s race in Xiamen, in the eastern Fujian province, with about 60% aged at least 35. Last year’s competition welcomed 443 participants over 41 years old; this year, it’s up by nearly 50% to 666.

To take part, Challenge Xiamen requires proof of prior race experience, while enhanced safety measures have been introduced for middle-aged entrants, including comprehensive medical insurance and the sharing of real-time health data with on-site medical teams.

Before preparing for his first triathlon in 2022, Wang Ou, 42, didn’t even know what the sport involved. “I thought it was javelin, discus, and shot put,” he said. Later, he joined the Xiamen Triathlon Sports Association, and noted that the 35-60 age group made up about 40% of participants in most races.

“It’s not just three sports — it’s strategy,” he told Sixth Tone, recalling his debut race. “I overkicked in the swim, wrecked my legs, and barely survived the bike. Learning to pace is the real challenge. I’m eager for my next triathlon. I want to take on a longer distance and keep pushing my limits.”

Many older enthusiasts say that their families are initially opposed to triathlons due to the sport’s rigorous nature — “They were worried I might exhaust myself,” Wang said — yet Michael Suen, a content creator in Shanghai with 40 races under his belt, believes the opposite.

“Although triathlon may seem to require significant physical activity, age is not a decisive factor in this sport,” argued the 40-year-old, pointing out that it is the ultimate endurance test. “Athletes aged 20 to 35 excel in explosive power, but over 35, endurance becomes your strength.”

Suen got involved in the sport after being diagnosed with thyroid cancer in 2015. What started as part of his rehabilitation evolved into a passion — by setting goals and following a scientific training plan, he not only regained his health but saw all his medical indicators normalize through consistent exercise.

Cao agreed that middle-aged individuals are not at a disadvantage when it comes to physical strength, and that a mature mindset is actually a perfect fit for triathlon.

“It’s not an explosive sport; it requires a person to have patience,” he said. “The training process is long even for a half-triathlon, so it requires perseverance.”

For Wang, the sport has brought about “earth-shaking” life changes. His weight has dropped from 115 to 90 kilograms, and he’s quit bad habits like staying up late, smoking, and drinking. As a result, all his health indicators have returned to normal.

Seeing the transformation, his family has gradually accepted his passion for triathlon. “They feel that I’m more disciplined and positive now,” he said.

The relative career stability of middle-aged participants is also an advantage, according to Li Xiaoqiang, a 39-year-old entrepreneur from Hefei, capital of the eastern Anhui province, who began competing in 2023.

“The daily regimen requires significant time investment,” he said. “Young professionals just entering the workforce often struggle with overtime demands, making participation difficult.”

Although he was similarly constrained in his youth by work, running his own company now allows him to easily schedule training and out-of-town competitions.

Finances are another factor. Participating in races around the country not only brings transportation and accommodation costs, but there’s also the cost of the bike, wetsuit, and running shoes. On Taobao, one of China’s largest online marketplaces, some top-level triathlon bicycles are priced at over 70,000 yuan ($9,750).

“Triathlon is considered the sport of choice for middle- to high-income groups due to its high equipment and entry costs,” says Liu at Challenge Xiamen. “It can also meet the self-realization needs of participants and provide a platform for expanding their social circles.”

The social benefits can be valuable, said Cao, who regularly joins training sessions run by his neighborhood running group. “It’s more than just exercise. The camaraderie creates emotional rewards, turning solitary workouts into lively social events while offering valuable technical advice,” he said.

However, following a scientific training plan and persevering in the long term are essential challenges facing every middle-aged triathlon enthusiast. “Triathlon is a scientific sport. If you can find an organization, go for it. Otherwise, you may harm your body,” warned entrepreneur Li.

Wang agreed, adding that triathlon requires “training the brain first,” while scientific workout plans can help people achieve balanced growth.

To further popularize the sport, Wang and several friends established the Xiamen Dynamic Advance Triathlon. The group holds two public running training camps every week, offers occasional comprehensive physical training classes and group swimming classes, develops individual training plans, and invites elite triathletes to provide advice. So far, it has attracted 15 members.

During training, group leaders not only exchange skills but also share with older members how to manage their time effectively.

“At our age, most of us are busy with older and younger family members. We guide them on how to balance training, work, and life,” Wang said, adding that he sees triathlons as a “regulator” for his career and home life.

“Middle-aged people inevitably encounter dissatisfaction in work and family. If you have such a regulator, it can help you release a lot of pressure, and the so-called ‘midlife crisis’ will naturally be resolved,” he said.

Editor: Hao Qibao.

(Header image: An athlete celebrates after finishing the swimming portion of a triathlon in Deqing County, Zhejiang province, June 2025. Wang Shucheng/VCG)