Is exclusive breastfeeding and its duration related to cardio respiratory fitness in childhood?

Aims and objective: This study investigated the effect of breastfeeding on cardio respiratory fitness (CRF) in students of Kermanshah, Iran.Methods and materials: In this retrospective cohort study, 246 students with the meanSD age of 7.280.50 years, mean breastfeeding +/- SD duration of 8.20 +/- 10.26 months, and body mass index (BMI) of 16.96 +/- 3.03kg/m(2) participated. Students had no CVD, liver or kidney diseases. Children were categorized in three groups of over 6 months breast-fed (>6 months group), less than 6 months breast-fed (6 months group), and formula group. The physician measured CRF calculating VO2 max; and reported the results as fitness or no fitness. The probable confounders were gender, BMI, fat-free mass, fat mass, mother's BMI, dietary Poly Unsaturated Fatty Acid (PUFA) and folate, beginning time of supplementary nutrition, physical activity, and birth weight.Results: Breastfeeding more than 6 months was positively associated with CRF (p value<0.001) before and after adjustment for confounders. The risk ratio (RR) of no CRF was 3.22 times more than >6 months group. VO2 max (ml/kg/min) was significantly the highest in >6 months group (p value=0.001).Conclusion: Breastfeeding more than 6 months has positive effects on CRF, and the early nutrition may be a predictor for adolescence physical health.