Duchess of Cambridge blends in with the crowd to cheer on London Marathon runners

The Duchess of Cambridge was joined by Princes William and Harry at the London Marathon this morning as they prepared to support the 40,000 runners taking on the 26 mile race.

The royal trio met with 700 individuals running in aid of Heads Together; the mental health charity (and official London Marathon 2017 charity) they have pioneered.

Hoping to make this year’s race the “mental health marathon”, Harry revealed that all three were “tempted” to take part “but it was probably safer and easier for us not to and to try and do our best to lead the campaign and let the focus be on the Heads Together runners.”

Kate arrived in a suitably casual look, opting for a black fleece jacket – branded with the Heads Together logo – and trousers to blend in with the crowd. She paired her weekend outfit with her favourite white Superga trainers.

The royals pushed the red button to officially start the race and will be dotted along the course to shout support at the competitors.

Over 40,000 people are expected to run at this year’s London Marathon, making it a record year for the annual event. It is hoped that the marathon will raise millions for the eight charities under the Heads Together branch.

Kate, William and Harry have had a busy week opening up about their personal struggles. Prince Harry revealed he sought counselling after his mother’s death in 1997 while William spoke to Lady Gaga about her experience with PTSD.

A BBC documentary aired this week also shed a light on several mental health conditions. Mind Over Marathon followed a group of hopeful marathon runners working with the royals.

Prince William was visibly moved at the documentary screening, saying: “We need to make mental health normal, and we need to treat it in the same way we treat physical health. It has to be seen in the same way.”

Click below to see every outfit the Duchess of Cambridge has worn while carrying out her royal duties:

Follow us on Instagram and Facebook for non-stop inspiration delivered fresh to your feed, every day. For Twitter updates, follow @YahooStyleUK.

Read more from Yahoo Style UK:

Duchess of Cambridge continues love affair with skirt suits in Armani

The Duchess of Cambridge uses secret Mumsnet account to seek parenting advice