Imagine a small house perilously close to a cliff edge. A cliff edge that’s pounded daily by bullying waves that threaten to tip that little house into the ocean. That’s how I see my relationship with fitness: I am the little house, the waves are late nights, the tug of age. And one of those waves is definitely made of white wine.Like the cottage’s owner, I am keen to build some defences to try and prevent a too-rapid descent. So, long gone are most things that taste delicious and I make sure that I get to the gym, run, cycle. But wow, those waves are persistent.So I have added another seawall: yoga. And I am not alone: the proliferation of yoga classes and kit-makers shows that this union of mind and body is having another moment. In an age of mindfulness and stress awareness, it’s the exercise that promises it all. It’s certainly become a key part of my weekends.But I am not buying into all the serenity nonsense. As far as I can see, yoga is as mean, competitive and likely to leave you feeling annoyed as any other sport.This isn’t just because I struggle to deliver the moves with the “elegance” the teacher requests (my diving eagle definitely looks more like “sparrow shot in the rump with an air rifle”). No, even the first five minutes is normally enough to kill my mood.Now, if I was in charge, I would bolt the doors once the class started. But the teacher just lets people keep drifting in – while simultaneously trying to get you to close your eyes and focus on your breathing. The laggards loudly dispose of coats and bags and then they try to insert their mats right at the front. (I have one contemptuous eye open; my breathing now resembles that of a wolf. A very bite-y one.) A certain attendee does this trick every week. I admit it, I have wished her ill. If I was the teacher, I would also ban anyone with a persistent cough or a tendency to sneeze. Sorry.There is also a category of (usually male) student who is convinced that they – not me – should be in charge. From your downward dog you spy them going adventurously freestyle or guessing every next move just to stay one step ahead of you, the unenlightened. Or how about standing on your head while everyone else is packing up to go home? (“Topple, topple,” you chant in your mind.)Then there’s the social danger. Tell anyone that you go to yoga and if they are similarly inclined they will want to know what type, how hot the room is, how long the class is and what mental state you reach. They dig into their inner Serena Williams to thrash you: “You should come to my three-hour class when you feel you’ve improved.”I worried that I was the only one getting hardened and attitude-y from yoga. But then a few weeks ago my views were ratified when one teacher rocked up in a T-shirt emblazoned with the words “Namaste Bitches” (there’s an online TV show of the same name). I loved her straight away.It’s good exercise and I can easily cope with some meanness with my stretches – but I have not booked the ashram just yet. And there is always hope – no, not of improvement. Mine is that Mr Headstand will befall the fate of another yoga show-off, as told to me by a good friend. The fellow got into a tricky move, let out an extended windy blast and was never seen in class again. Ha! Namaste bitches, indeed.