The 'experts', who are supposed to know about such things. Go for a brisk 30-minute walk three times a week, and the pounds will fade away. Work out at the gym twice a week, and those 'bingo-wings' will disappear. A few little sit-ups, and you'll flatten the 'muffin-head' spilling over your jeans. Take the stairs. Leave the car at home. Do butt clenches at your desk. Watch the weight fall off.

Don't believe a word of it. I began a strict exercise regime nine months ago, and with a middle-fingered salute to biology, my body decided to gain a few pounds. You'd think I'd be disheartened. But not so. The following is a diary of my progress, and the reason why I've never felt better.

Month One . . . Week One . . . The Weigh-In First day. All hyped up. Wearing baggiest of baggy tee-shirts, rescued from murky depths of hot press. In a month, shall ditch it in favour of figure-hugging sports bra. (Important to have high goals. ) Pat Henry's gym on Pembroke Street is to be the location of all exercising activity.

Right beside the office. No excuses not to go.

And it's a small gym. Nowhere to hide. Motivation, see.

Time to get measured and weighed. Brilliant. Simply cannot wait. Angie, one of the fitness instructors, whips out a measuring tape, and starts with my neck. Never really thought about having a fat neck. Until now.

On she goes, waist, hips, bum, bust, calves.

Getting a bit lightheaded from holding breath. Measurements are duly recorded.

Next, the professional-looking scales. Step on. Good God. 9st 11lbs. Clearly, they're broken. Never been more than 9st 7lbs. Never.

Although haven't weighed myself in a year.

Chin up. Clothes weigh at least 4lbs. And had very big breakfast, eight hours ago.

Angie looks at me kindly. "You probably don't want to lose weight anyway, do you?"

she says. "Just tone up a little bit?" Right, I say. "Wrong, " says Pat Henry, who is busy measuring my wrist. My six-inch wrist, he explains, means my optimum weight is 9st.

Just 11lbs to lose. Couldn't be that difficult, right?

First Time Exercise class is beginning upstairs. Am gently herded in that direction. No problem.

Am young, and relatively fit. Not worried.

Climb last stair, slightly out of breath.

Women twice my age are swivelling weights on their little fingers. Music starts pumping. Women start bouncing around. My journey to fitness has begun.

Five minutes in. Feeling great. Giving it everything. Can do this. Really can.

Ten minutes in. Painfully out of breath. A few blood vessels have packed it in. Eyes bulging from sockets.

Twenty minutes in. Muscles trembling.

Lungs heaving.

Ten minutes to go. Glaring at the clock as if it murdered my mother. Staring at fitness instructor in much the same way.

Done. Wait for everyone else to go downstairs. Will take me somewhat longer. Clutch the banister. Legs wobbling. One step at a time. Pat watches me hobble towards the door. "Tomorrow at five, " he says. "If I have to collect you myself."

Morning After Can't walk. Consider calling ambulance.

Stretcher to work would be nice. Decide against it. Am forced to climb stairs to office backwards . . . knees refuse to bend upwards.

Nonplussed receptionist, who has clearly been watching progress, offers a smile. Her eyes say I'm mad. Attempt reassuring grin, but facial muscles also hurt. Put it down to all the grimacing.

Sit at desk. Shriek in surprise. Pain, allencompassing pain, running up the back of body. Feel grim satisfaction. If level of physical agony is any indicator, will have sleek, toned muscles by end of week.

Evening After Crawl in direction of gym. Don't want Pat collecting me. Do a little time on stepper machine. Feel looser with every step. Kind, kind Angie offers to stretch me out a little.

Painful, but worth it. Feeling optimistic.

Like I've been knocked over by a bus and hit by a train and am now recovering.

Week Two Getting into it now. Able to walk after each session. Progress. Am doing 15 minutes jogging on treadmill, followed by squats, lunges, leg raises and lifting light weights for arms.

Tonight, will try doing everything twice.

May well kill me. But already seeing little results. Legs and arms slightly tighter. Have more energy. Feel strong, like an ox.

Thursday . . . go to gym and forget to bring tracksuit bottoms. Wonder if I did it deliberately-by-accident. Decide against doing situps in a skirt. Go home. Consider a brisk walk, to compensate. Keep considering while eating bag of Maltesers and watching new episode of CSI. Too dark for walk now. Not safe.

Week Three Have disastrous, fantastically fulfilling weekend. Meet old friends, eat four-course Indian, followed by copious quantities of alcohol.

Beer. Not fat-free vodka. Spend next day recovering, with the aid of big pub lunch. And tub of Ben & Jerry's 'Fish Food'. Mmmmm.

Monday . . . Skulk into gym feeling less fit than two weeks ago. Avoid making eye contact with anyone. Pat's words ring in head.

"It's 60% about what you eat, and 40% about exercise." Do extra five minutes on treadmill, and two circuits, for my sins. Manage it all without too much effort. Pat says am doing very well. Very proud.

Notice punch-bag hanging out the back.

Have just seen Million Dollar Baby. Resolve to be just like Hilary Swank. Will get wraps to protect delicate knuckles, and then start punching. Will be kick-ass karate artist.

Like Buffy, without the Vampires. Can't wait.

Week Four Bring in my wraps, raring to go. Have informed everyone of boxing ambitions.

Square up to punch bag. Hit it, punch it, whack it. Leaving Hilary in the ha'penny place. Giving it everything. "They're little girly hits, " says Pat. "Put your shoulders into it."

Punch harder, imagining certain face on red surface of the bag. Whole body in action now. "Better, " says Pat.

One long minute later, am knackered.

Three sets of three minutes, with 30-second break in between. Feel like long string of jelly.

Wobble home. New respect for Hilary.

One Month Later . . . Second Weigh-In It's been one month now. Feel different. Feel good. Have greatly improved diet. Apart from occasional ice-cream/Indian binges.

Now to get weighed.

"9st 12lbs, " says Angie. Heart plummets.

Impossible, hateful scales. Have gained a pound. Fight urge to scream. "You will have built up muscle, which weighs more than fat, " explains Kind Angie. Try to believe her.

Begin to imagine weighing scales on punch bag.

Three Months Refuse to go near scales. Instead, focus on clothes feeling looser, and muscles feeling stronger. Have so much energy. Feel like running for the bus even if it's miles away and I'm already at the bus stop. I'm unstoppable. Can't stop flexing my biceps to display to innocent bystanders. Muscles developing all over the place. Feel sleek and toned, like a racehorse. Ignore previous ox comparison.

Six Months Still in gym, and have also taken up Kai Bo, an aerobic type of martial arts. Love it. Do little karate kicks in office, when no one is looking. Bound to be caught one day. Have explanation ready . . . swatting fly with foot.

For sake of this article, and for no other reason, have decided to be weighed again at end of month.

Seven Months Kind Angie says I look thinner. Don't say anything, but am obviously delighted. Step on scales. "Just under 10 stone, " says Angie, mercifully not putting an actual figure on it.

But truth is clear. Have put on another pound. Am officially heaviest have ever been. Ever. After seven months of sustained, focused exercise and change in diet.

Unbelievable.

Spend rest of evening grilling unfortunate boyfriend about body shape. Poor chap.

Nine Months It's the end of my fitness diary and I've come to accept that, for me, exercise is not a mechanism for losing weight. I've also come to realise that I don't really care.

I won't stop exercising. I'm fitter than I've ever been, and I've never felt better.

My energy levels have quadrupled in nine months. I sometimes wake up before my alarm in the morning, and I sometimes even go to the gym before work. (I used to think people who did that were crazy. ) I'm so bouncy, it's a little nauseating.

Clearly, if I seriously wanted to lose weight, I'd stop tucking into a tub of Ben & Jerry's every weekend. I wouldn't eat Indian meals.

I'd shy away from Chinese takeaways. I'd never enjoy my 'Twirl-dipped-in-tea' Sunday evening ritual. I'd disown all carbs. And I'd definitely cut all my portions in half.

Ha. Not a chance. Food and I are the best of friends, and I will not break up a beautiful relationship for the sake of a few pounds.

Much more content am I to eat what I want, when I want. And never, ever wander near a weighing scales ever, ever again.