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Research suggests short bouts of exercise lengthen life

16 August 2011 Last updated at 11:32 BST

The latest advice on exercise suggests that you do not have to run marathons or spend hours in the gym to be healthy.

New research suggests that just 15 minutes of moderate physical activity per day increases life expectancy by three years, compared to inactive people.

Moderate activity could be anything from vacuum cleaning to gardening to brisk walking.

BBC Breakfast's Dr Rosemary Leonard and fitness expert Joanna Hall explain more.