Introduction: Physical activity (PA) guidelines emphasize the association of PA with numerous health benefits. This interaction occurs in part through components such as weight control and improved functioning of physical fitness. Women at menopause often experience body mass gain, particularly fat mass. Thus, the former PA also could enhance weight control and physical fitness. Aim: To evaluate the influence of PA performed at young age, on body composition and physical fitness in postmenopausal Spanish women population aged over 55 years. Material and methods: A battery of validated physical fitness tests (aerobic capacity, upper and lower strength, agility and walking speed) was applied to a sub-sample of a broader study (96 women, 55–88 years) living in Madrid (Spain). PA activity performed at younger ages and age of menopause was asked by means of the EXERNET questionnaire. The body composition variables analysed were body mass (kg), fat mass (%) and lean mass (%) measured by DXA (GE/LunarPRODIGY. GEHealthCare, Wisconsin, USA). Results: Postmenopausal women who practiced PA (30%) when they were young showed significantly lower body weight (yes: 61.3±10.4kg vs. no: 67.1±9.3kg; p=0.009) and fat mass (yes: 21.7±8.4% vs. no: 27.9±6.9%; p<0.001), better aerobic capacity (yes: 14.0±1.4mLkg−1min−1 vs. no: 13.1±1.7mLkg−1min−1; p=0.032) and higher body strength (yes: 16.17±3.33 rep vs. no: 14.66±2.79 rep; p=0.040) than those who did not practice PA. However, no differences were found in lean body mass (p>0.05These results were obtained after controlling for age, age of menopause and current PA (hours/week). Conclusion: PA performed at younger ages enhances body mass and fat mass, as well as aerobic capacity and physical fitness in postmenopausal women. Supported by Instituto Salud Carlos III (PI11/01791). ImFINE and NUCOX belong to the EXERNET research network.