Fighting fit: Sedentary toddlers are at greater risk of becoming obese adults. More than 40 per cent of Irish children undertake less than the recommended level of physical activity and 20 per cent are seriously inactive, according to research by Dr Tony Watson, director of the Growth and Development Centre at UL.

And the National Association for Sport and Physical Education in the US recommends that toddlers accumulate at least 30 minutes of structured physical activity daily, and that pre-schoolers should have at least 60 minutes per day.

The Irish Heart Foundation urges that "the prevention of heart disease must start with habits established in childhood." Eileen Derby took this advice so seriously, due to her family history of fatal heart disease, that she decided to put her 18-month-old son Alex on an exercise programme. She has since become franchiser of an international exercise programme, Stretch-n-Grow. The programme is based on fun, music and popular characters like Bob the Builder (who is looking a little tubby lately) and Buzz Lightyear. Pre-school children aged two to five take a 45-minute class once a week with trained instructors. Parents can continue the programme daily at home.

Simple stretches and exercises are the order of the day, but the tots also learn the mechanics of their bodies, the importance of healthy eating and hygiene as part of a two-year curriculum.

The cost is €55 euro for 10 weeks and there are centres around Dublin and its environs. For details telephone: 832 2653.