Three times a week Eva Blacklock puts on her tracksuit and heads to the gym for a work-out.

A circuit of the hall at Didcot's Wave Leisure Centre sees 76-year-old Eva using the treadmill, step machine and rowing machine, then moving on to lift various weights.

It sounds like a punishing routine but Eva, of West Hanney, has been doing it thrice-weekly for about seven years. She says she wouldn't give up her gym sessions for the world.

Eva, chairwoman of Age Concern Oxfordshire and the City, is one of a growing number of pensioners who are exercising to keep in shape and become more mobile.

Many have led active working lives and say exercise helps keep them feeling young.

The older generation is putting young people to shame. A recent survey says that women over 65 are doing almost twice the amount of exercise as those half their age. It adds that younger women are put off by gym culture and feel embarrassed with the way they look while working out.

As more women move into the workplace many claim they don't have enough time to keep fit.

But female pensioners such as Eva say they couldn't feel more at ease in a gym. Her personal trainer has worked out a special programme for her to follow that takes into account her age and level of fitness, and that will not put her body under any dangerous strain. And Eva even says she is not the oldest person to use her gym.

She says: "Going there keeps me pretty well in shape. I didn't used to go when I was much younger, but I took it up because it's so important for older people to exercise and make sure they keep mobile.

"About 10 years ago I started a keep-fit class for older people and found that people enjoyed it. It's so necessary for older people to keep fit - as long as they don't overdo it," she says.

The survey, by the Imperial Cancer Research Fund, shows that almost 50 per cent of women over 65 exercise every day, compared with only 26 per cent of those between 25 and 34. Despite the booming British fitness industry, one in five women is classed as obese. Of the 514 women who took part in the survey, more than half of the under-34 age group said they felt embarrassed going to the gym.

Seven in ten of the over-65s, however, said they looked forward to the gym and felt relaxed when there.

Research also shows that young people have a more sedentary approach to life.

They prefer to drive short distances rather than walk to shops or to visit a friend.

Many find that by driving they can shave a few minutes off the time it takes for them to get from A to B. However, problems finding a parking space can mean that any precious moments saved are soon lost. Despite their inactive approach to life, more young people than ever are on a diet or trying to lose weight.

Hundreds of women will take part in The Imperial Cancer Research Fund's Race for Life, which will take place in Oxford on June 25.

The runners are hoping to raise thousands of pounds for research into cancers that affect only women, such as breast and cervical cancer.

A spokesman for the charity said: "We wanted to find out why women generally do not exercise.

"It appeared that most forms of modern exercise do not appeal to women and a more 'back to basics' approach was needed."