January is the dreariest month. The days are short, the skies are grey and if, like me, you survived Christmas by anaesthetising yourself with food, the thighs are flabby.

But before you compound your gloom and embark on the Atkins diet, contemplate a different option. Many nutritionists claim that weight loss is based on the simple equation, “calories in” versus “calories out”. And while this, of course, means eating moderately, it also implies exercise.

Indeed, exercise can help to beat the January blues because during physical activity the body produces “happy” endorphins (natural opiates). With attractive flushed cheeks and a warm glow of post-exercise smugness, you will feel much better than if you were suffering the inevitable side-effects of Atkins (halitosis, constipation and, in my case, the uncontrollable urge to eat every potato in the universe).

I am not suggesting you high-tail it to the gym, however. Gyms are anathema to most “right-thinking” individuals: boring, competitive and so twentieth century. No, I am recommending that you follow the example of celebrities such as Sarah Jessica Parker and Kylie Minogue and take to the barre.

Devotees in New York, London and Paris cite suppleness, strength and a sculpted silhouette as the chief benefits of a ballet-based fitness programme. Deride it, if you will, as the “matrons in tutus” flash phenomenon, but increasingly exercise professionals are referring to ballet as the “new Pilates”. Its benefits have been noted by the New Zealand All Blacks, who in the past have incorporated ballet moves into their training routine, and the Aston Villa player Dion Dublin, who used it when he was recovering from a leg injury.

Charlotte Toner, 41, a former professional ballerina, has been at the forefront of this trend. Five years ago she developed her adult floor barre class, which incorporates elementary ballet and Pilates-type movements. “I fell into teaching it because my friends were always asking how I kept my figure,” she says. “Then I discovered there was so much demand that I had to get my act together and produce a proper timetable.”

Injured dancers often do floor barre because, as the name implies, you work mainly lying on the floor rather than standing at the barre. Since the back is supported, it is a relatively safe form of exercise.

Joy Walter, a leading chartered physiotherapist, says: “This combination of movement and stretch, underpinned by stability, is a good model for most people with back problems.”

Floor barre is also an ideal exercise routine for the post “nymphette” female (ie, all of us over 25) because it concentrates on the real problem areas: bottoms, thighs and stomachs. The legs are worked “turned out”, which elongates rather than bulks up muscles, and numerous abdominal repetitions trim the tummy.

Ballet’s focus on lengthening rather than contracting muscles promotes flexibility and is key to maintaining a lithe body as one grows older. Think Madonna, Kristin Scott Thomas and Helen Mirren: women whose looks belie their years. And results are quick too. “If you attend class regularly, you will notice a difference in body shape within four weeks,” Toner says.

She offers a variety of classes (each class lasts for an hour and a quarter) ranging from complete beginner floor barre to advanced ballet. Participants span the generations and for those of us who come to ballet later in life it is comforting to realise that you do not need the co-ordination skills of an acrobat or the fitness levels of an Olympic sprinter to attempt a plié at the barre.

“If you can walk on a treadmill,” Toner insists, “you can do floor barre. Co-ordination, elegance and suppleness come with practice.”

I was recommended to take up floor barre when persistent lower back pain prevented me from working out in the gym. After a six-week course with Toner, attending three one and a quarter hour sessions a week, my back improved and muscle tone was starting to replace dimpled flab. I also lost 10lb (4.5kg) effortlessly: somehow glimpsing my podgy reflection (in triplicate) in the studio mirrors eviscerated my desire for chips and chocolate.

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