Pick up those feet - the fat is gaining

By MARTIN JOHNSTON, health reporter

Sorry, the daily walk no longer cuts it. To burn off fat and maintain a healthy lifestyle, you should be puffing too much to talk.

Or you could wash the car for 45 minutes, or mop the floors.

New guidelines issued by the Ministry of Health recommend at least 30 minutes a day of moderate exercise and something a bit more vigorous - like climbing stairs for 15 minutes, skipping, running 2.4km or biking 6.4km in that time.

Doctors say evidence is mounting that vigorous exercise does more than burn fat. It helps people to avoid a range of diseases.

But if you prefer something less vigorous, you can get the same benefit by spending more time at it. Raking leaves for 15 minutes, for example, or gardening for at least 30 minutes.

The ministry says you are exercising moderately if you can still hold a conversation.

The guidelines are aimed at limiting New Zealanders' expanding waistlines.

Half of adults and nearly a third of children are overweight or obese, and this "epidemic" - blamed on sedentary jobs, too much television and meals with too much fat and sugar - is worsening.

It is also a big factor in the predicted 77 per cent rise between 1996 and 2011 in the number of people with type two diabetes.

A ministry survey found that nearly 40 per cent of adults were "physically inactive", doing less than 2.5 hours of leisure-time physical activity a week.

Children's health specialist Dr Paul Hofman said any exercise was good.

"But there is increasing evidence suggesting that more intensive exercise - I'm not talking to the point of exhaustion, but exercise where you have a sweat and increased heart rate - is more beneficial," said the Starship hospital endocrinologist.

"If you want to maximise the health outputs, it does have to hurt a little, but not lots.

"I'm really against the idea that it's okay to just have a gentle walk in the park and think it's adequate exercise. It's not going to reduce your fat mass."

A spokeswoman for the Fight the Obesity Epidemic group, Wellington Hospital endocrinologist Dr Robyn Toomath, said there was growing evidence that as well as burning fat, hard exercise helped to switch off some of the bio-chemical processes in diabetes and related conditions.

Cancer Society spokeswoman Carolyn Watts said vigorous exercise had also been linked to a reduced risk of some cancers.