OBJECTIVES: This study determined the effect of enriched foods and all-around physical exercise on bone and body composition in frail elderly persons. METHODS: A 17-week randomized, controlled intervention trial, following a 2 x 2 factorial design--(1) enriched foods, (2) exercise, (3) both, or (4) neither--was performed in 143 frail elderly persons (aged 78.6 +/- 5.6 years). Foods were enriched with multiple micronutrients; exercises focused on skill training, including strength, endurance, coordination, and flexibility. Main outcome parameters were bone and body composition. RESULTS: Exercise preserved lean mass (mean difference between exercisers and non-exercisers: 0.5 kg +/- 1.2 kg; P