Find time to stay fit

While cardiovascular exercise is crucial for maintaining health and well being, it's strength - or resistance - training that will make the biggest impact on your mid-life body shape. 'Basal metabolic rate - the rate at which we burn calories at rest - begins to decline from 25-30 years of age,' explains John McCarthy. 'The volume of lean muscle tissue decreases too, by about four per cent per decade. The result is an overall loss in metabolically active tissue and a gain in highly inactive adipose tissue [fat].' One pound of muscle will demand approximately 35 calories per day, simply to function, while a pound of fat needs just one or two calories.

By increasing lean body mass through resistance training, this decline can be reversed. A study by strength training expert Wayne Westcott found that 12 weeks of regular resistance training resulted in a loss of 4lbs of body fat and a gain of 3lbs of lean muscle tissue. 'The best way to achieve this is to perform a total body strength workout two to three times a week,' says McCarthy. It's not necessary to join a gym to do resistance training - you can use your own body weight for many exercises or invest in dumbbells or resistance tubing to use at home. If you don't know what type of exercises to do, consult a personal trainer or a good book, such as Strong Women Stay Slim, (£12,99 Aurum Press) by Dr Miriam Nelson.

A word of advice, though: start slowly. In the US, sports medicine professionals have coined the phrase 'boomeritis' to describe the wide variety of injuries they are seeing as a result of mid-lifers - or 'baby-boomers' - taking to exercise too enthusiastically. As a rule of thumb, increase the intensity of your workout by no more than five per cent a week.