"I've taught over 10,000 students in my time, and the only thing I've ever wanted is for them to get their bums in."

John Kells

Because when the bum is in – when the sacrum is directly under the heart – then the heart is always being directed upward, like a fountain. And remember: the bum is in but the tail is out, otherwise the knees, and your sense of humour, will suffer.