Gwyneth Paltrow takes on Ice Bucket Challenge – and nominates Chris Martin

stripped down to her bikini and stepped up to the

this week. The actress joined the

who have been

and donated money to the ALS Foundation. But before being soaked in her

, the 41-year-old revealed she was

to take part.

"Hi, I'm going to alsa.org to donate money for ALS, but in the meantime I'll do this and nominate

,

and

," she told the camera, in a video posted on her Instagram. A friend then tipped a bucket full of cold water all over the star, who

and started to run away. Gwyneth and Chris, 37, famously announced they were "

" back in March but have remained on very good terms.

 

Since then, Chris has been

, 24, while Gwyneth is

producer

.