He recommends a mixture of overall aerobic exercise with general toning of the arms - and if that doesn't work it may be that you just have to accept your genetic makeup.

Whatever the outcome, don't go to extremes. 'The problem with encouraging people is that they'll reduce their body fat so drastically they begin to feel unhappy because of that sticking point,' he says.

Singaporean Cathy Sung is one of many women with saggy upper arms. 'I hate the fact that even though I'm slim generally, whatever flabby bits I do have seem to deposit solely in my upper arms,' Sung says. 'Wearing certain clothing, like spaghetti strap tops or sleeveless shirts or dresses, makes me self-conscious. Even when I've lost weight through other measures, my arms aren't at all toned.'

Devereux suggests trying a mixture of cardiovascular and muscle-toning exercises for three to six months to see if that makes a difference.

Spot reduction - targeting the arms with weights alone - won't have a dramatic effect, he says. What's needed is a mixture of overall fat reduction with toning exercises for the upper arms.

Even if the results aren't immediately dramatic, there are hidden bonuses to toning the arms. 'With most people, if you put in the time and effort, you'll see improvements,' he says.

Research has also shown that arm exercises help prevent peripheral vascular disease (PVD), a disease of the blood vessels outside the heart and brain that narrows the vessels carrying blood to the arms, legs, stomach and kidneys.

Last year, a study at Sheffield Hallam University followed the progress of more than 100 patients with PVD who were put through some basic arm exercises. Their cardiovascular function and walking ability both improved.

Sam Hui, fitness manager at Seasons Fitness, recommends doing triceps exercises with medium weights for an upper arm workout.

He suggests high repetitions - about 15 or so - in sets of three or four. 'If you're watching TV, every 15 minutes you have a commercial - so do the sets about four times during the programme,' he says.

The triceps are the muscles at the back of the upper arms. For an all-over arm workout, fitness experts suggest routines that work the triceps, along with the biceps (the muscles at the front of the upper arms) and the deltoids (the rounded shoulder muscles).

Triceps extensions are popular exercises to help tone the backs of the upper arms.

Lying on your back - preferably on a bench - hold the weight above your chest at arms' length, and with your upper arms taut, lower the bar until it's almost touching your forehead. Then raise the bar back to the starting position, and repeat up to 15 times.

You can also try the triceps pushdown, where you stand in front of a bar attached to a weight machine and pull it down towards you with both hands. Keep the arms rigid against the side of your body, bend the elbows and push the bar down further until your forearms are parallel to the floor, bringing it back up to the starting position.

A simpler way of working the triceps is to sit on a bench with your arms behind you and slowly lower your body down to the floor using your own body weight.

Hui says many exercises can be done at home without weights - if you have a water bottle, fill it up and use that instead.

'For a normal woman, you should be looking at a weight of three to five pounds,' he says.

Basic bicep builders include the curl - where a weight is lifted towards the chest - but as Hui points out, for many women the front of their arms isn't the problem area. 'The fat is usually at the back of the arms,' he says.

He stresses that targeting specific areas will only work in tandem with overall exercise. 'You must do a lot of cardio,' he says. 'If women want to have a good shape for July and August, you have to do it now.'

Hui recommends some form of cardio exercise at least three times a week. 'If you do less than that, you don't do enough exercise to change the body.'

The time spent on cardio workouts should be at least 30 minutes, he says.

For the arm exercises, Hui suggests working the triceps every other day to begin with. 'Once you do it more regularly, you can work them every day,' he says. 'Just keep them working.'