Jaci Stephen: 'At my Beverly Hills gym there's only Victoria Beckham for company'

Seven months after joining the Beverly Hills branch of Sports Club LA, I am no nearer to finding a group sport that I enjoy. My daily workouts are undoubtedly enhanced and encouraged by seeing the exquisite form of Victoria Beckham on a nearby treadmill, and even more so a couple of weeks ago, when Mr Beckham also turned up in the gym, a sight that induced in me so severe a case of Beckhamitis, I swear I had two birthdays in the time it took the paramedics to bring me round.

Exercising alone enables me to go at my own pace, and I have discovered that if I exercise to music rather than watching marathons of Law and Order or NCIS, I go a lot faster on the treadmill. Musicals are particularly effective, and this week alone I have exercised my way out of prison (Les Miserables), shot my twin brother (Blood Brothers), and had plastic surgery to enable me to sing "Tits and Ass" with sufficient verve (A Chorus Line).

But put me in a class and all my concentration and good intentions go to pieces. First, I tried boxing, because I have always been a huge fan of the sport. As a child, my brother and I were allowed to watch Mohammed Ali's fights, which always began at 8pm – but only if we first went to bed at six and slept for two hours. Punching somebody's lights out took on metaphorical as well as real significance in our household, and to this day I love boxing.

My first and only boxing class in LA ended in disaster. When I entered the empty gym, I just wasn't prepared for the rotating mechanical punchbags zipping their way round as I waited in line for the class to start. Zap! The first one arrived and smacked me square on the gob.

After that, I found the class a little stressful. "I give you 10 seconds, I give you nine seconds, I give you eight seconds ..." On and on and on. The teacher counted every damned second of the hour-long class to every single movement we made – all accompanied by ear-splitting disco music.

Having enquired at reception as to what might be a quieter, less dangerous class, I decided to try Anusara yoga. It was very, very calming. At the start, the teacher said she had been "talking" to a 16-month-old child, with whom she had been sharing the youngster's enthusiasm of the new world the little girl was experiencing. Enthusiasm. That was the "intention" she asked us to focus upon over the next 75 minutes; or, failing that, any other intention (mine was ensuring that I record the last episode of My Antonio, a show for which I have immense enthusiasm, so I felt I was killing two – actually, I don't think killing is a Yogic term, so let's say I was anaesthetising two – birds/intentions with one stone).

It was all going well up until the cobra position. It was an exercise I had done in the past, when I taught myself a bit of yoga and needed to release trapped gas. I tell you: the class was the entire wind section of the LA Philharmonic. If the point of yoga was to co-ordinate breathing with movement, I couldn't see that having to hold my breath for the next five minutes to avoid the smell was going to do me any good at all.

I tried Power yoga instead, in the hope that the speed of the thing might at least circulate any bad odours. This time I lasted just half an hour, when the teacher encouraged the class to make noises while they inhaled and exhaled – "like sea-shells". Somehow I found myself among the tidal wave contingent and just wanted to tell them all to shut the hell up.

My concentration also wasn't helped by the teacher again telling us to focus on any "intention" we liked – world hunger, if we so wanted: something that, he added, was always on his mind ... starving people the world over ... and yet nothing was ever done about it ... Look, mate: I know, but you've just said that this is MY time, MY space, and MY body to do with what I like with MY intention. Now you've gone and blown My Antonio right out of my psyche. I rolled up my mat and skulked out.

I have decided that I am just not a group exercise sort of person and am therefore returning to the treadmill and the stepper with just my earphones and the TV on the machine for company. And Dave and Vic, of course. Now there's a couple you won't hear breaking wind in public.

To read Jaci Stephen's blog LANotSoConfidential in full, go to Lanotsoconfidential.blogspot.com