It’s been 25 years since I last did a Pilates class, and now I’m remembering why I strayed for so long. The movements are precise, the positions very specific and the classes can be eye-wateringly pricey. But as I’m lying on my back in Michelle Kemp’s Northern Sky reformer Pilates studio in Worthing, with limbs suspended in straps, doing repetitive sequences and feeling those core muscles tightening, I know that when you get it right, the results are amazing.