Call to arms; The latest cosmetic procedure promises to deliver the slim, tight, toned arms of our dreams.

Byline: Julia Jones

At mile 24 of the New York City Marathon, my ensemble is still remarkably impressive: a curve-clinging sleeveless shell with my name emblazoned in sequins; snug boot-cut running pants; waterproof jet-black mascara holding up masterfully under beads of perspiration.

As I wave excitedly to a gaggle of friends, the illusion of physical perfection is suddenly shattered: The flab of my upper arm continues waving long after I've passed by. Yes, the taut, smooth upper arms of my 20s have given way to saggy, pudgy-looking blubber.

Physically, I am in the best shape of my life: I can sprint a 5K, effortlessly complete a 50-mile bike tour, and endure triceps dips ad infinitum. I can easily slip into my skinniest jeans; I'm happy to show a slither of toned, flat stomach. Yet my arms remain the one thing that stubbornly refuses to yield to any exercise or healthy eating regimen. As much as a scraggy neck or a sun-spotted hand betrays its Botoxed owner's true age, flabby arms are an equally frustrating giveaway.

Am I doing the wrong exercises? Or is it just because I'm getting older and gravity is taking its viselike grip? Do flabby arms-like cellulite, stretch marks, and thin hair-simply fall into that unfortunate category of "Sorry, but you're born like this?" (Even marathon runners have cellulite, I noted during the race, as the legs of one woman in front of me jiggled wildly as she ran toward the finish line.)

Determined, I look into further fitness options. At Casa, the chic gym in New York's Regency Hotel, trainer Melissa Peretz has created a five-minute circuit program specifically for the arms. The regimen-push-ups, shoulder presses, biceps curls, lateral raises, Pilates-based movements, front and side raises-are all performed during the course of one circuit, so you never stop moving, and which is why it's only five minutes long. "You want to focus on the shape of the arms, so the definition gives the illusion of them being slimmer," says Peretz.

Celebrity trainer Marc Felberg delivers a crushing blow: "There are certain parts of the body, like 'saddlebag thighs,' where women store fat," he says. "You can have strong triceps, but a layer of fat on top will hide the muscle. As women get older, their skin loses elasticity, and even a rigorous arm-exercise routine won't work."