My 'friend' brought me to her spinning class before I started SW and was almost 4 stone heavier than I am now... it wasn't a beginners class, but I didn't know that! I literally stepped off the bike afterwards and couldn't feel my legs.. I felt faint and thought I was going to keel over (I'm not exaggerating!). It was a week before I could walk up and down the stairs properly. LMAO when I think back now... I never want to step foot inside a spin class ever again. I know I'm a lot fitter now, but I still have nightmares..