Children need more exercise to cut heart risk: Study

Instead of one hour a day of moderate physical activity, young people may need to do 90 minutes to stave off high blood pressure, raised cholesterol levels and other risk factors that can lead to heart problems.

"Physical activity levels need to be higher than the current international guidelines of at least one hour per day," said Lars Bo Andersen of the Norwegian School of Sports Science in Oslo.

Andersen and his team assessed the impact of exercise on 1,732 children from Denmark, Estonia and Portugal, aged either nine or 15.

They compared the amount of exercise they did every day and measured their risks of developing heart disease.

They found that the more the children exercised, the more their combined risks factor score decreased.

Nine-year-olds who did 116 minutes of moderate to vigorous exercise a day and the teens who exercised for 88 minutes daily had the lowest risk factor scores, according to the research published in The Lancet medical journal.