Book excerpt: You might be wondering what Ronnie O'Sullivan is doing writing a book like this. What do I know about eating healthy, right? I'm a champion snooker player, not a personal trainer or a chef and although I've always loved running, I've come to realise that any success in sport is directly related to my attitude towards food as well as fitness. Snooker is all about sharpness, focus, and concentration - how can I do any of those things if I'm not eating well and treating my body right? My game is only as good as I am, so making that link between my mental and brain health and my physical fitness was a lightbulb moment for me and I hope this book will be a wake-up call for you too. We hear lots about mindfulness and self-care these days, but really good physical health starts with the best computer any of us could ever hope for - our noggin (aka our brains!). Written with top celebrity nutritionist Rhiannon Lambert, Top of Your Game is about showing you how to eat, think, and work your way to being your very best - and staying there.