The Duchess wore a casual ensemble for a SportsAid engagement today.
Kate has been SportsAid’s Patron since 2013. The organization “helps young British sportsmen and women aspiring to be the country’s next Olympic, Paralympic, Commonwealth and World Champions” per a Palace news release. Kate took off her blazer before getting involved with some of the training exercises. 
Below, the Duchess chatting with athletes at today’s event. 
The charity provides financial support to more than 1,000 athletes each year, helping them with expenses like training and competition costs. 
My guess is this gentleman, and some of the others seen above are pole vaulters.
Today’s function was a celebration of the role that parents and guardians play in their child’s sporting success. More from a SportsAid news release:
The parents and guardians are often the ‘team behind the team’ and the financial element is just one of the many crucial forms of unseen support that they provide. They willingly take on many different roles – including that of taxi driver, personal assistant, sports psychologist and lead nutritionist. Most athletes train twice a day and travel nearly 1,500 miles every month to train and compete.
The Duchess spent time speaking with parents, guardians, and coaches about those roles. 
And heard about the challenges they face as well as the pride they feel about their athlete’s accomplishments. 
She also watched and took part in some of the training. Here you see parasprinter Emmanuel Oyinbo-Coker (l) showing Kate how starting blocks work. On the right in the red hoodie is Jessica Ennis-Hill, DBE. She is the 2012 Olympic champion and a three-time world champion in heptathlete. 
Emmanuel Oyinbo-Coker makes sure Kate is set in the blocks for a little race action. 
And they were off. 
More from this Telegraph story:
Known as a keen sportswoman, she won praise for her technique from the athletes after asking to have a second go at coming out of the blocks and beginning to run down the track.
“I think she did really, really well,” Ennis-Hill, 34, one of the heroines of London 2012, said after coming out of retirement to show off her technique.
“I felt really nervous. I hadn’t been in a pair of blocks for years.” Tokyo Paralympics hopeful Oyinbo-Coker, 18, agreed.
None of the three looked too terribly serious. 
The Palace tweeted a video of the sprint-training. In it, you can also see wheelchair racer, Danny Sidbury.
?♀️ Sprint training at @TeamSportsAid with Jessica Ennis-Hill, Emmanuel Oyinbo-Coker and Danny Sidbury #SupportTheNext pic.twitter.com/xYCvnjYjmy
— Kensington Palace (@KensingtonRoyal) February 26, 2020
Kate after the race. 
And with Jessica Ennis-Hill.
It looked like everyone very much enjoyed themselves. 
One of the cool things that happened at today’s event: Kate read Jessica Ennis-Hill’s original application for aid that was submitted to SportsAid back when she was 15 years old.
The Duchess is taken aback as she reads the application Jessica Ennis-Hill submitted to SportsAid as a 15-year-old. The form was written by Jessica and she informed the charity that her long-term ambition was to ‘compete in major championships’. She did a bit more than that! pic.twitter.com/hQV55cQOIq
— SportsAid (@TeamSportsAid) February 26, 2020
Below, Dame Ennis-Hill alongside her application.
Kate saw practices for taekwondo and other sports. She even took part in the taekwondo. 
Russell Myers from The Mirror posted a video of Kate being taught how to throw a reverse punch.
Whoa! Kate packs a mean right hook ? ? pic.twitter.com/p28lov7Ice
Read the latest on Kate at the London Stadium today with SportAid https://t.co/NPadzQS1lG— Russell Myers (@rjmyers) February 26, 2020
We learn more from The Telegraph’s coverage:
During the event she also tried her hand at taekwondo, packing a powerful punch into some pads after a few minutes of coaching from Olympic athlete Lutalo Muhammad, who hopes to add a gold medal in Tokyo this summer to the silver and bronze medals he has won at the last two Games.
“Her right hand was mean,” he said. “Trust me, that was a hard punch. It was better than expected.
“She passed with flying colours. I’m glad I didn’t let her punch me.”
Another view.
The Duchess watching judo practice. 
At today’s function, the Duchess also spent time with other supporters of the charity, including trustees.
The Duchess is spending time with SportsAid trustees, led by chair Mike Westcott, as well as several long-term supporters of the charity. The line-up also includes Ellie Challis, winner of SportsAid’s One-to-Watch Award in 2019, her father Paul, Leon Taylor and Ama Agbeze! pic.twitter.com/oI51tgErqI
— SportsAid (@TeamSportsAid) February 26, 2020
Kate delivered remarks at today’s event.
You may not always feel appreciated, or sometimes even noticed on the sidelines, in the car park or sitting high in the stands. But I am so proud that SportsAid recognises how key your role is and that they understand the challenges and worries you face.
For all of you here, you go, and have gone, above and beyond the call of duty; you’ve committed your time and devotion to nurturing your children’s exceptional talents”
A video of her at the podium.
“For all of you here, you go, and have gone, above and beyond the call of duty; you’ve committed your time and devotion to nurturing your children’s exceptional talents”
The Duchess shares her admiration with the parents and guardians as she addresses them at the @LondonStadium! pic.twitter.com/6IyVzigXA7
— SportsAid (@TeamSportsAid) February 26, 2020
More from her speech:
On behalf of SportsAid, I’d like to thank all the parents and guardians who have played, or are playing, their part in developing this country’s young sporting talent. Finally, I know this is an incredibly exciting but daunting time for many of SportsAid’s young athletes, so I’d like to wish the best of luck to all those aiming to participate in the Olympic and Paralympic Games this year. We’ll all be cheering you on.
A group photo.
And now we turn to our look at what Kate wore to London’s Olympic Park this afternoon. 
We’ll begin with the Duchess’s oft-worn Smythe Duchess Blazer ($695). 
The jacket is 100% wool with a snug, fitted silhouette. It features peak lapels, welt pockets at the chest and waist, brass buttons, and that distinctive back cutout. The piece is available at Saks in most sizes; it is offered in a mix of sizes at Farfetch; and at Smythe.
The top worn by the Duchess appears to be by Mango, the British retailer’s Ribbed Knit Sweater ($19.99). The piece is a ribbed knit that is 78% viscose/22% polyamide, with a deep round neck and long sleeves. 
Thank you to Middleton Maven for her ID of the top.
It looks like Kate may have been wearing a pair of Zara Culottes (originally $49.90, most recently selling at $7.99). The culottes are a high-waisted style made of 100% polyester with wide legs and a hidden side zipper. 
A big ‘thank you’ to Elizabeth at Kate’s Closet for this ID!
Kate debuted a new pair of sneakers. They are the Ribbon Detail Lace-Up Trainers ($50) from UK retailer Marks and Spencer. 
The trainers are described as having the Marks & Spencer “Insolia Flex® technology, endorsed by the UK College of Podiatrists for comfortable walking.” The product description also says they are “made from vegan-friendly materials.” A Tip of the Tiara to Emily for IDing these; it would never have occurred to me to look at Marks and Spencer.
We saw the return of Kate’s ‘Siren’ Green Onyx Earrings ($175) by jeweler Monica Vinader. 
A quick refresher on the earrings, described as “organic, irregular shaped multi-faceted Green Onyx gemstone… encased in 18ct Gold Plated Vermeil on Sterling Silver” on the Monica Vinader site.
Kate brought back her Daniella Draper personalized necklace, the jeweler’s Trio Diamond Midnight Moon Necklace (£1270, roughly $1650 at today’s exchange rates).
On the far left, the piece as worn today; it looks like the back of the piece we’re seeing in that tiny photo. The front has the initials G, C, and L for the three Cambridge children.
VIDEOS:
The Royal Family Channel offers more than three minutes of coverage in this video.
This Telegraph piece runs almost two minutes.
LINKAGE:
- Learn more about SportsAid at its website here; follow the group on Facebook, or on Twitter.
- See the full text of Kate’s remarks by clicking here
- The Telegraph’s story is here; a Daily Mirror coverage is here; The Daily Mail’s piece is here; an Evening Standard story is here
- a People piece is here; a Hello article is here; a PopSugar gallery is here; the Fug Girls post is here; Caroline Hallemann’s Town and Country piece is here
Seh
Saturday 7th of March 2020
Chiming in v v late here, but I had to say I don't understand all the hating on the pants (we give them an "s" on the end here in Oz!). A wide leg surely looks good in any length if u r as tall as Kate is. It's true she has a long torso, but this only tends to show itself when she tries to hide it by having v short jackets (sometimes altering the buttons or waist line) & " peplum" type jackets. Cropped, wide pants had a very big moment here about 15 years ago, I think. Anyways, over a decade ago I had surely retired them, but they have sprung up like mushrooms again. They are tending to be linen & rigid here this summer, like the tobacco colored ones Kate wore to her Chelsea garden the first day. But back in the day a cool local label called Morrison brought them out in a vaguely stretchy material without a zip even, the top doubled over again to form a firm panel over the waist. Must see if I still have them!! The shoes are absolutely fabulous: I wld love them! The little stripes are so retro & pick out all the other greens. I agree with Laura about the "tonal" look she is working here...I like it myself: a symphony of greens or blues together! I've noticed Kate will use an accessory like an earring (her Zeen ceramic drops r a good example), or a hat etc, which contains a mix of a number of shades of the same colour as her clothes, to bring all her slightly clashing "tonal" greens (or whatever) together for a great effect! Have always adored those earrings. Gorgeous: never get sick of them. She has worked the full on sports look for a number of occasions & it's nice to have a point of difference for this sort of day. Wasn't she having a ball that day?! She really is so darling. The whole post was a treat: Thank u Susan!
Shannon
Monday 2nd of March 2020
She looks so cute with the ponytail
Larissa
Sunday 1st of March 2020
I think the fact that Kate was not only spending time with the athletes but also giving a speech and meeting trustees that required her to step up from simple athleisure, and I like the idea behind this outfit. I'm still not sure if I'm completely sold on it. I appreciate the mismatched greens and actually think they look great together. And the trainers are the perfect finish to the look – surprised at the negative reaction to them here. I don't know if it's a young person thing (I'm 27) or a European/London thing, but everyone I know and everyone I see in the street has a classic pair of white trainers that go with every outfit. In fact, last summer after living in London for a couple of months, I actively sought out a pair of white trainers because sandals aren't allowed in my workplace and I needed something to match my jeans, trousers, and the skirts I ended up living in for most of the summer. Kate is spot on with her choice here, I love the additional greens.
That necklace is a beautiful addition to Kate's collection. You can't go wrong with a pendant, and the length makes it so easy to pair with many different necklines. I'm glad Kate can easily add a sentimental piece like this when she is out working.
Lee B
Saturday 29th of February 2020
great post! cute outfit!
Susan
Friday 28th of February 2020
It’s a weird look that occasionally photos well only because she’s so stinking cute and happy. I hate those shrunken blazers that can’t close. And I believe she has on suntan panty hose which are dreadful and especially with white tennis shoes. Super ugh but she is somehow still gorgeous
Liza Peters
Tuesday 3rd of March 2020
Kate is right on point with style! White trainers ( or black) are a huge current style (with everything, actually) as well as cropped wide-leg pants (jeans, too!) and are not just a fad. Tucked in or semi tucked,also for shirts or sweaters. Monochromatic is popular also, especially with a jacket or blazer, worn unbuttoned. Gives you the essential three colors (no more) and is also slimming, not that Kate needs that. And finally, polyester (viscose) has come a long way and I turn to it frequently now for fit and comfort or cotton/poly blends. I don’t see any problems with Kate’s outfit!!