The 53-year-old singer - who became the most successful artist in British history yesterday when her new album `MDNA` became her 12th number one - admits children Lourdes, Rocco, David and Mercy don`t enjoy listening to her records. She said: "My kids are brutally honest when it comes to what they don`t like. They have no tact whatsoever. "They`ll just say, `Mum, get that song off` even when mine. It`s hurtful but at least they`re honest." Now gearing up for her upcoming world tour, the `Hung Up` hitmaker says she has been hitting the gym like never before in order to deliver the performance of her life. She told The Sun newspaper: "I have to say that in more than 25 years of performing I have never worked so hard or been so scrupulous. Or freaked out more than I have at the minute. "My whole life has been a combination of hard work and prayer. Preparation is essential but you need as many angels watching over you as possible as well. I`m getting ready for rehearsing my world tour so I have been in training. "There`s been lots of cardio and I`m doing a combination of pilates and dance cardio. And there`s been plenty of skipping rope work. The envelope I`m pushing for is as spectacular a show as I can. It should be a feast for the eyes and ears."