Differences in fitness according to AA intake (tertiles) in adolescents adjusted for study centre, age, family affluence scale, average physical activity, total daily energy intake and carbohydrate intake (g/day). Boys’ tertiles in mg/day: tryptophan (<1052.2, 1052.2–1289.8, >1289.8); histidine (<2483.5, 2483.5–3113.7, >3113.7); methionine (<1989.5, 1989.5–2496.1, >2496.1); leucine (<7154.7, 7154.7–8835.8, >8835.8); proline (<6538, 6538–8098.7, >8098.7). Girls’ tertiles in mg/day: tryptophan (<804.9, 804.9–987.6, >987.6); histidine (<1898.4; 1898.4–2367.5, >2367.5); methionine (<1509.6, 1509.6–1898.4, >1898.4); leucine (<5435.1, 5435.1–6766.1.8, >6766.1); proline (<5000.3, 5000.3–6063.6, >6063.6). Tertiles were calculated with raw data to be more meaningful although differences were examined with the log-transformed variables. All p > 0.05. CRF cardiorespiratory fitness