Mike Tindall is no stranger to a gruelling challenge, and on Wednesday, the former I'm a Celebrity…Get Me Out of Here! contestant was supported by fans after revealing he is taking on another brutal task.Taking to his Instagram account, the former England rugby star, 44, shared the exciting news that he is taking on a gruelling 12-hour fitness challenge for 4Ed's, a charity dedicated to rugby player Ed Slater who suffers from Motor Neurone Disease.WATCH: Mike Tindall jokes about wearing Zara's hats againCaptioning the post, he penned: "Sooooooo it’s going to be a late one Saturday night and Sunday!!! Not in my usual way though!! But all for an amazing cause and person in @ed_slater @4edfundraising please support in whatever way you can. If you would like to donate please text 4ed and your donation to 70560.