 A. Determinants of Peak Bone MassSizeArchitecture, Soft Tissue Development and Risk Factors for Cardiovascular disease During Growth Question: Regulation affecting growth and peak bone mass? Can increased exercise increase bone mass, reduce fatness and risk factors for cardiovascular disease? Could individuals with high risk for fractures be predicted already in early ages? Hypothesis: Changes in environmental factors can increase peak bone mass, reduce fatness and risk factors for future cardiovascular disease. Bone mass track so that we could already in young years identify individuals with high risk for fractures. 