Allyson Felix: Five reasons the sprinter will forever be a legend
In April, US sprinter Allyson Felix announced this year would be her last as an athlete.
It's hard to imagine what the sport will look like without her.
Felix burst on to the scene in 2003 when, aged 17, she finished second in the 200m at the US trials to qualify for her first World Championships.
wo medal-filled decades later, she bowed out in front of a home crowd in Eugene, Oregon, winning bronze as part of the 4x400m mixed relay.
"It was a night I will cherish. I've had such good memories," she said. 
"I know it is time and these guys will carry it on into the future. I am at peace stepping into this next stage and have tremendous gratitude for this sport."
As careers in sport go, they don't get much better than Felix's - and off the track she's had some pretty momentous achievements too, with her activism showing how speaking out can spark real, tangible change.
Here are five reasons Allyson Felix will go down as a track-and-field legend:
Even if you don't follow athletics, you are likely to have heard of the sport's biggest names - Usain Bolt, anyone?
Felix deserves a place in that group of track-and-field icons. Her gazelle-like running style delivered on the biggest stages time and again to cement her place in the history books
She has won more Olympic medals than any other American track-and-field athlete in history - and seven of the 11 she has taken home are gold. 
She's also won more World Championship medals than anyone else - 19 across five events, 13 of which were gold.
We're all familiar - perhaps too familiar - with the term 'GOAT' in sport, but Felix truly is one of the greatest athletes we have ever seen.
But it's not just what she's done on the track that makes her great…
In November 2018, Felix gave birth to daughter Camryn eight weeks prematurely after discovering she had pre-eclampsia, which could have been life-threatening to both her and her baby.
Camryn - born weighing three pounds seven ounces - spent her first month in intensive care. 
Pre-eclampsia is disproportionately prevalent among African-American women in the US, and Felix's experience inspired her to raise awareness of maternal mortality.
In 2019, she spoke at the US Congress.
She said: "After enduring the two most terrifying days of my life, I learned my story was not so uncommon. There were others like me, just like me... black like me, healthy like me and doing their best, just like me. And they faced death like me, too.
"We need to provide women of colour with more support during their pregnancies. There's a level of racial bias within our healthcare system that is troubling and will be difficult to tackle, but that doesn't mean we shouldn't."
Speaking on Thursday, her US team-mate Noah Lyles - the 24-year-old 200m world champion - said Felix had been a role model to him growing up. 
"For one black woman to speak their mind and speak for what they believe is right, even have the courage to try, is something I feel young people should be watching for years to come," he said.
Felix's words quickly turned into activism - and as well as being one of the most successful athletes in history, she is using her voice and platform to speak out about women's rights. 
It's having a big effect.
In May 2019, she wrote an opinion piece for the New York Timesexternal-link explaining that her sponsor Nike wanted to pay her 70% less after she became a mother. 
"I've always known that expressing myself could hurt my career… but you can't change anything with silence," she wrote.
"If we have children, we risk pay cuts from our sponsors during pregnancy and afterward. It's one example of a sports industry where the rules are still mostly made for and by men."
ree months later Nike changed its stance on maternity pay and promised not to apply any performance-related salary reductions for 18 consecutive months, starting 18 months before the due date of pregnant athletes.
After parting with Nike, Felix launched her own footwear company.
And she is still fighting for maternal rights. This season she partnered with her new primary sponsor and a non-profit organisation to provide free childcare for athletes, coaches and other participants during the 2022 US trials. 
"I'm trying to leave the sport better than I found it, trying to support female athletes and women in general and fight for more equality," she said.
And in her retirement announcement on Instagram, she made it clear using her voice would be a big part of her future.
"This season I'm running for women," she wrote. "I'm running for a better future for my daughter. I'm running for you. More to come on that, so stay tuned, but I'll be sharing a series of announcements that I'm hoping will make the world better for women." 
After her experience with pre-eclampsia, Felix told Time magazineexternal-link she remembered thinking: "I don't know if I'm going to get back. I don't know if I can."
But less than a year after giving birth, she became the most successful athlete in World Championship history when she won two relay golds in Doha. 
She proved any doubters wrong again in 2021.
After a challenging year in which she struggled to find tracks to train on because of the coronavirus pandemic, the 35-year-old Felix qualified for the 400m Olympic final - but was the second-slowest to do so.
Anyone who dared doubt her was soon silenced as she came home in third, winning a 10th Olympic medal before adding an 11th in the relay.
When Felix first qualified for the World Championship, Hey Ya! by Outkast topped the charts, Finding Nemo was released and Nokia 3200s were all the rage. 
Almost two decades later she is still qualifying for major events in the most competitive national team in the world.
At 18, Felix won her first Olympic medal - silver in the 200m in Athens behind Jamaica's Veronica Campbell, setting a world junior record of 22.18 seconds in the process. 
A year later, she became the youngest world champion in history by winning the 200m in Helsinki - a title she would retain two years later in Osaka.
Her achievements are incredible, but are even more impressive when you consider the calibre of those she has raced against - the likes of Merlene Ottey, Sanya Richards-Ross, Christine Arron, Carmelita Jeter, Shelly-Ann Fraser-Pryce and Elaine Thompson-Herah. 
Versatility has been key, especially in relays, and given the strength of the US national championships, to win 10 as Felix has is a rare and formidable feat.
So considering everything this champion, mum and activist has done in and outside the sport, it's safe to say her retirement leaves a big hole in the world of athletics.