Why home is the new gym

The Lycra-clad Mr Motivator, returning to television screens today, may be an unlikely saviour for those feeling the pinch of waistband and wallet, as Britons swap health clubs for home fitness.

The fitness instructor Derrick Errol Evans, last seen on GMTV in the early 1990s, is launching a campaign to tackle inactive lifestyles. His timing is faultless: gym membership is predicted to decline by 20 per cent this month as the credit crunch bites. Exercising at home is back in favour, with sales of exercise DVDs up 65 per cent on last year.

"If you walk along any high street, you'll see bigger backsides than ever," Evans said. "And there's safety in numbers – as the people around you grow larger you stop noticing it.

"Nowadays, I see fat policemen," he said. "You never used to get fat policemen as they would be on the beat. Now, they are in their cars."

Evans, who lives in Jamaica and visits the UK to advise British businesses on fitness, believes we will only solve the problem of lifestyle inactivity, and consequent obesity crisis, if we work together as a community. He said he decided to return to television when he realised his 12-year-old daughter, Abigail, had become overweight when her school stopped dance classes. She has lost 18lb in the past two months. "There is a need for all of us to be more physical," he said. "In the 90s, we focused on bulimia and anorexia, which seem to me to mainly affect the middle classes. Meanwhile, people were eating unhealthily – and storing fat."

Evans, who is 56 but says his lifestyle ensures he looks "fabulous", believes schools should make physical activity more appealing. "Youngsters love music and dance. Don't say the class is about getting fit, get them exercising subliminally," he said.

His belief that exercise needs to be enjoyable to be effective is reflected in the rise of the Nintendo Wii Fit, which has sold more than 3.5 million copies worldwide, and the popularity of home fitness DVDs, many inspired by Britain's new-found love for dancing. Sales of fitness DVDs are up 65 per cent year-on-year, according to Tesco, and the Top 10 bestsellers include Dirty Dancing Fitness and Strictly Come Dancing: The Workout. The number of people taking part in dance-based exercise has increased by 83 per cent over the past four years, according to the Arts Council.

Exercising at home is also growing in popularity as people fail to renew their gym memberships. Consumer trends expert Jeremy Baker of London Metropolitan University, said: "Gym memberships are bound to be a victim of consumer cutbacks and a member drop-off rate of over 20 per cent is likely in January 2009. In the long term existing members will continue to cancel gym contracts and home, park and road fitness activities will become popular, giving a boost to the home fitness market."

Home fitness products are benefiting from the wane in popularity of health clubs. Home fitness machine supplier iJoy Products, whose products include the iJoyride, which simulates horse riding, saw a 34 per cent boom in sales in 2008. Evans's Get Motivated campaign will include an interview with Gordon Brown, which will be screened on Friday. The timing coincides with the launch of the Government's £75m Change4Life campaign to tackle the problem of sedentary lifestyles. The campaign aims to inform the public that, without intervention, by 2050 some 90 per cent of today's young people will be overweight or obese.

Ben Bradshaw, the Health Services minister, said: "This is the biggest public health campaign for years. Obesity costs the NHS £4bn a year, and the cost to the wider economy is some £16bn. Being more active does not have to cost money. In our current climate, where people are questioning the culture of excess, they may be more receptive to messages of moderation and healthy activity."

Despite Britain's new culture of moderation and his new campaigning role, Evans will continue to wear his trademark colourful Lycra. "I dress up the pill of fitness in a sugary coating," he said. "If I'd worn black shorts, people would never have noticed me. I want to remind the people who know me of old, while bringing in new converts."

Indoor athletics: How to burn calories

Fitness DVD: 220 calories for Pilates, up to 500 for aerobic exercise

The exercise video has made a huge comeback this year, with sales up 65 per cent and Big Brother presenter Davina McCall's Fitness 5 Super Body Workout topping the exercise DVD chart.

Dancing: 500 calories an hour

Inspired by Strictly Come Dancing, the nation has learnt to throw shapes. The Arts Council says 83 per cent more people take dance-based exercise than four years ago. Latest title in stores: Belly Dancing For Beginners.

Living room simulators: up to 400 calories an hour If you're unlikely to gallop across fields or snowboard this year, the iJoyride and iJoyboard offer a simulation at home. Sales up 38 per cent in 2008 and expected to rise.

Wii Fit: 150 calories an hour Melding computer gaming with yoga, push-ups, aerobics and strength training, the Nintendo Wii Fit has sold more than eight million copies worldwide.

Personal trainer: 500 calories an hour

Personal training is rarely a budget option, but trainers do visit you at home.