Background
The effect of exercise training on submaximal aerobic capacity and locomotor economy (LE) of Down's syndrome (DS) individuals has never been analyzed and their peak physiological adaptability to long-term physical conditioning is poorly understood. Thus the purpose of the present study was to determine whether DS males could improve their submaximal and peak aerobic capacity and LE after a 28-week training program.
Material and Method
Twelve Caucasian DS males aged 34.5+/-7.0 years (range: 21-49) underwent a 28-week aerobic exercise intervention consisting of two 40-min sessions of ergometer conditioning per week. Body composition was assessed by anthropometric and bioelectrical impedance spectroscopic measurements. Pre- and post-training submaximal physiological response was determined by means of a 2.5-km/h treadmill flat-walk. Graded maximal exercise tests were performed to investigate the participants' peak exercise capacity. Multivariate analyses of variance were performed to explore the influence of training on the subjects' body composition and submaximal and peak aerobic capacity not.
Results
After training, the participants decreased their fat mass from 27.3+/-11.2 to 23.5+/-11.1% (p<0.01) and increased their absolute fat-free mass from 48.4+/-8.6 to 50.8+/-9.3 kg (p<0.01). There were no differences between pre- and post-training locomotor economy (LE). However, the subjects decreased their respiratory exchange ratio from 0.91+/-0.11 to 0.83+/-0.05 (p<0.05) while exercising at the same submaximal workload. Peak exercise capacity improved 27.8% following training (p<0.01).
Conclusions
Despite improving body composition and peak cardiovascular fitness and lipidic oxidation during submaximal exercise, DS males were unable to modify their LE after 28 weeks of exercise intervention.

Keywords: Time Factors, Rest - physiology, Physical Fitness - physiology, Locomotion - physiology, Exercise - physiology, Pulmonary Ventilation - physiology, Down Syndrome - physiopathology, Body Composition - physiology