Background and aims: We explored the associations between aerobic physical fitness with blood lipids and a composite index of blood lipids and fasting glycaemia in adolescents, analysing possible interactions with weight status. Methods and results: Body mass index and aerobic physical fitness was measured in 2090 adolescents (1034 mates and 1056 females) 13-18.5 years by using the 20-m shuttle run test. Plasma glucose, total, high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol, triglycerides, apolipoprotein (apo) A-I, apo B-100 and Lipoprotein(a) [Lp(a)] were measured in 460 of the 2090 subjects. After adjustment for confounding factors, a continuously distributed summary score for blood lipids and fasting glycaemia was significantly related to aerobic fitness in mates (P = 0.018) and females (P = 0.045, from the 2nd to the 4th quartile of aerobic fitness). After adjustment for gender, age, sexual maturation and economic status, aerobic fitness was related to the composite index of blood lipids and glycaemia in both overweight and non-overweight adolescents (P < 0.05). However, for the same level of aerobic fitness, the composite index of blood lipids and glycaemia was significantly higher in overweight adolescents (P = 0.001). After setting the minimal aerobic fitness standards to present a healthy lipid profile, about 50% of mates did not reach such values. Conclusion: Our data suggest that both aerobic fitness and weight management are associated with a composite index of blood lipids and glycaemia in adolescents. Our study also provides the minimal levels of aerobic physical fitness associated with a favourable lipid profile in mate adolescents, a new tool which should be adopted by schools as "aerobic fitness standards". (c) 2006 Elsevier B.V. All rights reserved.