NEW year, new you - the first two months of the year are times of reinvention, when New Year resolutions are usually adhered to, before being abandoned in March.

Losing weight and staying fit and healthy are among the top ten New Year resolutions in the UK, while research in the USA put them as the top two, at 33 and 38 per cent respectively.

They way in which we keep fit has changed dramatically over the years. In the 1970s most people went to keep fit classes held in local community centres, school gymnasiums and draughty church halls.

Classes would be regimented, like a school games lesson, with the standard bend your knees, touch your toes and stretch-type movements. People wore either their normal clothes - as can be see in the 1973 photograph taken at Woodside Community Centre - or T-shirts and baggy tracksuit bottoms or shorts.

Classes were popular, especially with middle-aged and older people, who also saw them as much as a social occasion as a chance to get fit. They offered an opportunity to make friends. I remember the class in my home village in North Yorkshire was full of pensioners, who sat and had a cup of tea and slice of cake afterwards.

The wonderful picture of pensioners at Woodside Community Centre in 1973 shows a group taking part in seated exercise sessions, similar to those run today at sports and leisure centres and in residential care homes throughout the Bradford district.

Men were just as likely to want to get fit as women, with some classes being devised for men-only.

Some classes were linked to diet and it is clear from the photograph taken in 1970 at Eastfield Secondary School, Lightcliffe, that weight loss programmes were also in operation. The picture shows a group of men whose excess flab is being measured by a special tool.

A decade later, keep fit ‘studios’ began to appear in cities and towns across the country. Lined with mirrors they were not to everyone's taste - you could see how out-of-time you were with the other participants. It was quite depressing being at the front.

Early aerobics classes saw women - and the occasional man - in vest tops, tight jogging bottoms, leg warmers, head and wrist bands, gyrating to the likes of Jump by Van Halen, Survivor’s ‘Eye of the Tiger’ and, of course, Michael Jackson’s ‘Thriller’.

With all its stretching and bending, aerobics was quite a strenuous activity. Aerobic exercise is sometimes known as ‘cardio’ - exercise that requires pumping of oxygenated blood by the heart to deliver oxygen to working muscles.

Besides strengthening your heart and lungs, aerobic exercise can help lower your cholesterol, reduce your risk of type 2 diabetes, improve your immune function, and lower your blood pressure. It also burns up calories, which can in turn help you shed excess weight - which is, after all, the main reason people sign up for it.

Next came step aerobics - sets of choreographed movements performed on a small raised platform. Accompanied by music, the movements are designed to work the lower body, upper body and cardiovascular system. The 1990s also saw Lycra sweep through the fitness scene, the fibre being the new sportswear of choice for almost everyone. The tighter the better, some people felt, putting pressure on those of us who wanted to hide our limbs from scrutiny.

The emergence of gyms had a dramatic effect across the globe, with people of all ages paying to pound treadmills, ride bikes and lift weights in comfortable, heated buildings, many also featuring swimming pools and cafes.

Today the fitness industry is worth billions, with gym membership - which can be costly - common among people of all ages. Many gyms are open round the clock to fit in with people's busy lifestyles.

Every year new exercise regimes are introduced - we’ve now got the bicycle-based spinning, Zumba - a modern take on the 1970s phenomenon, Jazzercise - and the more relaxing pilates, to name but a few.

Fitness DVDs continue to be popular, offering people who possibly don’t want to get fit in public the chance to exercise in their own home. Celebrities such as TV presenters Davina McCall and Lorraine Kelly, and supermodel Cindy Crawford put viewers through their paces. The celebrity fitness craze began with the starts like Jane Fonda, whose work out videos gripped both the UK and USA in the 1980s.

Now living room fitness has moved on, with the Wii games console. Launched in 2006, it has pumped up the sector known as 'lounge fitness'. Wii Fit - which sees families 'playing' tennis, golf and football in their living rooms - has sold 23 million copies.