A new study has suggested that your kids need at least 90 minutes of exercise a day if they are to avoid heart disease when they are older - much more than the recommended amount of just an hour.

While guidelines suggest that 5 to 18-year-olds should take around 60 minutes of daily activity a day to reduce their risk of premature death, a new study published in medical magazine, The Lancet, warns that younger children need to be doing at least half as much again.

A lack of daily exercise and obesity are being blamed on junk food, TV and video games.