In her brilliant book Extra Time, journalist and government advisor, Camilla Cavendish, wrote that exercise and diet are so effective in helping us live longer, healthier lives, if they were a pill we’d all be taking it. (Read about the book and its rabble rousing examination of healthy ageing here)

Well, if you need living proof of the power of those two ingredients to help you reach older age in the best possible shape, literally, look no further than Lee, who was three weeks off being a frankly unbelievable 80 when we chatted. She started by explaining how and why she first got interested in exercise.

It’s hard to believe that Lee is very nearly 80!

“I got fat after one of my pregnancies and my mother dragged me to an exercise class in a dingy little church hall. We all had to walk round the room waving scarves around (this was the early 60s). It was absolute rubbish! Then somebody took me to a jazz class at a dance centre in central London. I loved it. It was so different. I started going every single day. I had five children, and dancing kept me sane. I used to take them to school, get on the tube and do an hour's jazz class with Arlene Phillips. It kept me calm for the rest of the day.

I heard myself say: “I’ll lead the class”

Then one day, one of the teachers didn’t turn up and there were 30 people waiting to do the class, and I heard myself saying, “I’ll lead it”. I knew the class backwards because I’d gone so often. So I taught the class, including making up a little dance routine at the end, and although I shook all the way hone afterwards, I thought, ‘You know, what? if I can do this and I'm an ordinary housewife, why shouldn't I learn to teach?’

So I did a training course and started teaching myself, and I’ve done it ever since. I had my own exercise studio for six years in the 80s, but it burnt down in a fire and I couldn’t find anywhere else, so I slung out my last child living at home (he was about 26, so it was time for him to go!) and I turned the whole top floor of my house into a studio. And I've been teaching here since then.

Lee’s pupils, who are in their 70s and 80s are as supple as she is

My classes are quite tough

I teach two classes a week and some one-to-one personal training sessions. My class is quite tough. It's dance based, but it’s evolved into aerobics and stretch as well over the years as I’ve done more courses and gone to other people’s classes. The women in my class have been coming to me for 40 years. They're in their late 70s and 80s and they are slim and supple as a result.

I really want to encourage everyone, whatever age, to do some exercise

I really want to encourage everyone, whatever age you are, to do some exercise. It doesn't matter what you do. Just find something you enjoy enough to do on a regular basis. Experiment. There are lots of council run classes which are not expensive at all. Go along with a friend, and just have a laugh. Even if you just go for a walk every day it'll make you feel so much better. You feel completely different.

If you’re nervous about exercising - perhaps you’ve had a fall and that’s knocked your confidence - just try and do something simple like arm and shoulder stretches to start with. And try to stand up straight. Sloppy posture makes you look and feel old, so try and do something about it.

What matters is how it makes you feel

And don’t compare yourself to anyone else. Exercising is about how it makes you feel. Even now, I’m not fit enough to run a marathon (nor would I want to!) I'm supple. I could dance to music for hours. But I get out of breath running to the letterbox.

Also, when you get to a certain age, it's more about maintenance, rather than striving to improve and improve. Because you won't. Just do what you can. The great thing about exercising is that you can't think of anything else when you’re doing it. You just concentrate. And then afterwards, a sort of calmness comes over you and and the problem was that you were struggling with before somehow seem clearer. You can cope.

Then I started writing

When I had my studio, clients used to ask me what do about their weight as well, so I started giving dieting advice. And then I thought, ‘Hang on, I better learn what I'm talking about here.’ So I did some courses in in nutrition. And then I started writing. I had my first book published in 1990, it was called Stop Bingeing. And four years later, I had another book published, called, Only Fat People Skip Breakfast.

My new book is called ‘Getting Older. Deal With It’

I’ve got a new book coming out in December called Getting Older, Deal With It.

I really want to dispel the notion that old people are frail, dim witted and what the newspapers insist are a burden on society. It’s nonsense. But it's all about how other people perceive older people, isn’t it?

Lee believes how you feel about yourself affects how others feel about you. And exercise makes you feel so much better about yourself!

Everything is a matter of perception

Everything is a matter of perception really. Not just other people’s, yours as well. It's about how you think about yourself. And how you feel when you look at yourself in the mirror. That influences how you behave, and that, in turn, will influence how other people behave towards you. If you feel good about yourself, you will project that spirit and positivity to other people. And they’ll treat you in a more positive way. So that's it in a nutshell really.”

What exercise have you tried that you love? And what did you have a go at that you didn’t?!