The Peep Show comedian, who was paired up with Dianne Buswell, withdrew from the series following an ‘urgent consolidation’ with a specialist monitoring his recovery from heart surgery.
Speaking about his time on the show, Robert said: ‘It is brutal. It is an absolutely weird show.’
He continued to The Sun: ‘It is not like it is an unpleasant environment, but they are long days and it is a long time to be nice.’
Robert added that he was often on the brink of tears in rehearsals as he struggled with learning the routines.
‘If we had longer to rehearse it would happen, but we get four days and one performance…,‘ he said. ‘At the end of that performance you might get fired. It is brutal. It is an absolutely weird show.’
Robert, who had open heart surgery two years ago, announced earlier this week that he was quitting Strictly after he had ‘begun to feel symptoms’ while training for the show.
He said in a statement: ‘I’m extremely sorry to have to announce that I’m withdrawing from Strictly Come Dancing due to ill health.
‘Two years ago I had open heart surgery and although I believed I was fit enough to take on Strictly and its demanding schedule, it became clear that I had bitten off way more than I could chew for this stage in my recovery.
‘I had begun to feel symptoms that led me to seek an urgent consultation with my heart specialist, and it was her view that it would be better for the sake of my health to step back from the show.
‘I’m proud of the three dances that Dianne Buswell and I managed to perform and deeply regret having to let her down like this.
‘I couldn’t have wished for a more talented partner or more patient teacher, and it’s a measure of Dianne’s professionalism and kindness that I was able to get as far as I did.’
Robert went on to thank viewers for voting for him and Dianne, adding he was ‘especially touched by the support from fellow heart patients’.
‘I think perhaps I was too eager to impress them. They will know that recovery doesn’t always go in a straight line, and I hope they’re not too disappointed that I ran into the limits of my resilience much sooner than I’d hoped,’ he said.
‘I leave knowing that Strictly viewers are in very safe hands and I’ll be cheering for my brother and sister contestants all the way to Christmas.
‘Despite this sad ending, it has been a genuine honour to be part of this huge, joyful and barking mad TV show. Long may it continue.’
During his time on the show Robert completed a tango, a cha cha and a quickstep.
Last week he finished 10th on the judges’ movie week leaderboard with a score of 25 for his The Muppets-inspired dance, which he performed while dressed as Kermit The Frog.