Ann Burrows is an example to grandmothers everywhere. The former dance teacher from Westbury-on-Trym has a shock of white hair, but looks at least 10 years younger than her 62 years.

Her healthy glow is in part down to the active lifestyle Ann has led even after she stopped being a dance teacher, when she retrained as a Keep Fit Association (KFA) instructor.

The association gives tens of thousands of women across the country the opportunity to get together in a spirit of fun and friendship to exercise regularly together. Each week in Bristol alone, there are 50 classes, three of which are taught by Ann.

And next month, current and former members of association are celebrating 50 years of their organisation at the Council House.

Clad in black at the class at Horfield United Reformed Church in Muller Road, Ann brings the very best out of her charges, aged from 18 to over 80, who are all dressed in black leotards and bright pink jackets.

These Pink Ladies are rehearsing a four-and-a-half-minute dance routine to a megamix of some of the songs from Grease, which they will perform at the KFA national annual meeting in Exeter in October.

They are all learning a new routine devised by Ann, and moving in time to the songs sung by Olivia Newton John and John Travolta.

Ann said devising new routines for her classes was something that came very naturally to her. "Music inspires me. I just keep listening to music and just keep jigging along," she said.

"I play the music over and over again and find myself moving around to it. I use the knowledge that I have acquired over the years and I can change the feel of the moves depending on the music."

The music in Ann's classes ranges from musical numbers to pop songs and modern classics. One of Ann's favourites is the music of the Scissor Sisters, a flamboyant pop group from New York who have recorded with Elton John.

No auditions have been needed to take part in the Pink Ladies' act. In fact, the only time the Avon branch of the association ever holds auditions is when it is occasionally asked to dance at the Royal Albert Hall as part of a biennial celebration of the organisation.

While many of Ann's class have been members for many years, others were not even born when some of their colleagues first joined. But what they all share is a love of dance.

Although their organisation has keep fit in its name, it is about keeping fit through dancing, which in Bristol takes place in a church hall in Horfield, a community centre in Patchway, a leisure centre in Easton, and many other venues across the city and the former county of Avon.

"First of all, we always have a lot of fun here," said Ann, who has been a member for more than 10 years.

"We have a lot of fun and it's also a good support group for a lot of people.

"If you belong to a gym, you go in and go out and that's it. With the KFA, it's so much more than that. When our husbands go away to play golf, we can meet up for classes or lots of other activities that we organise as a group."

While the association is not exclusively for women, the membership is overwhelmingly female. However, Ann does teach a handful of men in another class.

And of course she teaches women of all ages and all abilities, including one woman who takes part in the class in her wheelchair.

Sally Johnson from Horfield comes to Ann's classes with her 22-year-old daughter Louise. "These classes take you completely out of what you normally do," said Sally, 50, whose works as a school librarian.

"It's completely relaxing, you obviously keep yourself fit and we all remain young at heart. Some of the ladies remain young and so vibrant and I think that's really important.

"It's the use of the music and the use of our bodies to make us feel good. My daughter comes to the class and she loves it. The social aspect is also really important. You get to meet up with a group of like-minded people every week.

"Events like the annual general meeting in Exeter are really fun to work towards. We can have great weekends away where we can behave like teenagers again."

The association may have keeping fit as its mantra, but its members are all great friends.

They support each other in difficult times and provide many people with their core friendship group.

Sally joined the Avon KFA with her friend Becky Ottrey soon after they had both become mums and needed something as an excuse to get out of the house and have fun.

"I had children, but I did not have anything else," said Becky, 50, a student support worker from Stoke Gifford. "I was not going anywhere, but as soon as I first came to a class, I knew that is where I wanted to be and I've never looked back."

She added: "Dancing at the Royal Albert Hall was such a highlight. There's no way you can explain it. I never would have believed that I would be performing there one day.

"It was nerve-wracking but fantastic at the same time. It was hard work to prepare for it, although it was only a five-minute routine, but at the end it was so fulfilling and I was on cloud nine for days afterwards."

As well as attending the classes and social events, the association raises a lot of money for charity.

In recent years, Avon KFA has raised thousands of pounds for Hearing Dogs for the Deaf and the Jessie May Trust, a Bristol-based charity that provides a hospice-at-home service of nursing care and respite for children with a terminal illness.

Ann, Sally and Becky are not only all part of the KFA community in Bristol, but also the whole of the UK and Ireland, and they get a chance to meet up with members from across the country on regular occasions.

But it is their class in Horfield where they will always see each other and the rest of their friends.

"Listen to your body. That's really the key," said Ann when asked for any advice to would-be dancers. "And it's not always the younger ones who have the most energy."

The association would like to invite past members of the Avon area (formerly Bristol and District KFA) to its golden anniversary celebrations at the Council House in Bristol on Saturday, September 20, for lunch, memorabilia and displays.

Contact Margaret Yeo on 01454 614886 for further details or email margaretdyeo@hotmail.co.uk