The Duke and Duchess of Cambridge along with Prince Harry took part in a training session for the London Marathon in partnership with their mental health initiative Heads Together.
The royal trio joined 150 runners at the Queen Elizabeth Olympic Park who are taking part in the Marathon and fundraising for the eight Heads Together charity partners.
Kate kept warm in a red puffer style jacket.
She debuted the Perfect Moment Mini Duvet quilted down ski jacket (US$450). The contoured jacket by the French brand features navy elbow patches and black ribbed cuffs, as well as a magnetic flap over the upper part of the front zipper. The nylon exterior is lined with goose down.
Kate teamed the vivid red jacket with a black turtleneck top and black skinny jeans.
It's believed she is wearing the Zara Body Curve Jeggings (US$35.90)
Kate also premiered a new pair of black running shoes.
MiddletonMaven identified them as the New Balance x SB Exclusive Sneakers (US$145). Sweaty Betty have teamed up with New Balance for an exclusive collaboration. Available only in Sweaty Betty stores and online, this exclusive sneaker mixes fashion-forward prints with New Balance's technical sneakers. The colour is described as 'MAJORELLE GARDEN PRINT BLACK.'
We also noticed some new bling! Kate wore round pavé diamond stud earrings which bear a striking resemblance to her Asprey 167 Button Pendant Necklace.
The London based jeweler confirmed the Duchess wore their 167 button earrings.