The Goldilocks Day (IMAGE) University of South Australia Caption The 'Goldilocks Day' tells us the durations of physical activity, sleep and sitting that are 'just right' for children's optimal bone health. Credit University of South Australia Usage Restrictions Credit: The University of South Australia License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.