'Olsen Olympics': Mary-Kate and Ashley get into the competitive spirit as they celebrate 29th birthday with games and a dunk booth

Mary-Kate and Ashley Olsen celebrated their 29th birthday on Saturday, and instead of a glitzy soiree, opted for a day of casual outdoor fun.

They gathered their friends for the Olsen Olympics, divvying guests up into two groups – Team Mary-Kate and Team Ashley.

Wearing blue or red T-shirts showcasing their allegiances, the gang competed in a variety of outdoor sporting games.

Happy Birthday #TeamMK #OlsenOlympics

A photo posted by Yale Breslin (@yalebreslin) on

 An obstacle course was set up on a grassy field, complete with colourful cones, tires, and beams.

The festivities also included a dunk tank, which plunges someone into a tub of water.

A Happy Birthday poster was set up on the field, including the Olympic logo and images of medals bearing Mary-Kate and Ashley's names.

It seems their guests got quite competitive. 

Happy Birthday my beautiful MK. You will always be a winner in my book.. Except today ❤️�� #olsenolympics #werenumber1

A photo posted by Jared L. Seligman (@jaredseligman) on

Champions ���� #teamashley #olsenolympics #twinning #sorrymk

A photo posted by Jared L. Seligman (@jaredseligman) on

#OlsenOlympics

A photo posted by Yale Breslin (@yalebreslin) on

Jared L. Seligman, who was on Team Ashley, Instagrammed a photo with Mary-Kate, writing: 'Happy Birthday my beautiful MK. You will always be a winner in my book.. Except today #olsenolympics #werenumber1'

Instagram user bikinikilled posted a photo of her friend in the dunk tank, writing: 'Got #danconnor in the dunk tank, first try #olsenolympics'

It was likely a welcome break for the Olsen twins, who are busy women, helming a successful business empire that includes fashion lines The Row, Elizabeth And James, Olsenboye and StyleMint. 

Got #danconnor in the dunk tank, first try �� #olsenolympics

A photo posted by ALEXIS PAGE (@bikinikilled) on

Got #danconnor in the dunk tank, first try �� #olsenolympics

A photo posted by ALEXIS PAGE (@bikinikilled) on

Let the games begin #olsenolympics #campcounselors

A photo posted by @cassiecoane on

The twins recently won the CFDA Fashion Award for Womenswear Designer of the Year with their luxury brand, The Row. 

They have reached a decade with the brand, which generates tens of millions of dollars in sales, according to Elle magazine. 

The twins have largely set aside acting, recently passing on the opportunity to reprise their role as Michelle Tanner on the Full House reunion show, Fuller House.

An official statement from executive producer Robert L. Boyett attributed the choice to a 'focus on their fashion brands and various business endeavors.' 

American gal ����#olsenolympics

A photo posted by ALEXIS PAGE (@bikinikilled) on

�� Team Pookie ��

A photo posted by Rob Fishman (@rbfishman) on

Full House aired for eight seasons from 1987 to 1995, with Mary-Kate and Ashley alternating in the role of Michelle Tanner so as to comply with child labour laws. 

An official statement from Fuller House executive producer Robert L. Boyett attributed the choice to a 'focus on their fashion brands and various business endeavors.'

Fuller House will premiere on Netflix in 2016, featuring original stars Candace Cameron Bure, Jodie Sweetin, Andrea Barber, John Stamos, Bob Saget, and Lori Loughlin.

City gal: Mary-Kate was last seen out in New York on Wednesday, June 3 with her fiance Olivier Sarkozy 

City gal: Mary-Kate was last seen out in New York on Wednesday, June 3 with her fiance Olivier Sarkozy 

Casual outing: Ashley was seen stepping out in New York's Tribeca neighborhood on Tuesday 

Casual outing: Ashley was seen stepping out in New York's Tribeca neighborhood on Tuesday 

Congrats! The twins won the CFDA Fashion Award for Womenswear Designer of the Year for their luxury brand, The Row - pictured at the ceremony in NYC on June 1 

Congrats! The twins won the CFDA Fashion Award for Womenswear Designer of the Year for their luxury brand, The Row - pictured at the ceremony in NYC on June 1 

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