Physical activity assessment Physical activity was assessed in the whole sample using Baecke questionnaire for habitual physical activity [1], that correlates well with maximum oxygen consumption (VO2max)[2]. Maximal exercise test was performed in each subject on an electromagnetically braked bicycle ergometer (Ergoline 800, Bitz, Germany) to determine peak oxygen uptake (Vo2peak). An initial workload of 50W was increased by 25 W every minute continuously until fatigue despite the verbal encouragement. Oxygen uptake was measured using Vmax, Sensor Medics (Yorba Linda, CA). Heart rate was monitored continuously.