Acute and chronic effects of exercise in adults with Down syndrome

Doutoramento em Motricidade Humana na especialidade de Ciências da Motricidade.This thesis intended to explore both the acute and chronic physiological adaptations of persons with Down syndrome (DS) in response to exercise. Specifically, in terms of acute exercise responses, we aimed at investigating the submaximal exercise capacity and cardiac autonomic function of adults with and without DS. Subsequently, we determined whether 12 weeks of exercise training were effective in improving exercise capacity (economy and peak oxygen uptake – VO2peak) and autonomic function both in adults with and without DS. Overall, we found that the submaximal exercise capacity of adults with DS was characterized by poor walking economy, but appropriate VO2 kinetics. As importantly, these individuals demonstrated reduced cardiac responsiveness to changes in the sympathovagal balance resulting from submaximal dynamic exercise. Findings also indicated a breakdown in their fractal scaling properties of heart rate dynamics that was transversal to resting, exercise and post-exercise recovery conditions. Moreover, compared to nondisabled participants, adults with DS showed reduced cardiodeceleration during recovery from peak exercise intensities. Finally, in general terms, a combined exercise regimen resulted in gains of similar magnitude between participants with and without DS for submaximal exercise capacity and cardiac autonomic function. In conclusion, this thesis provides evidence that persons with DS have reduced submaximal exercise capacity and that this is paired by disturbed autonomic function. Nevertheless, these results also indicate that exercise training is an effective intervention for improving their physiological function in similar magnitude as in adults without DS.FCT - Fundação para a Ciência e a Tecnologia.PIDDAC, SFRH/BD/45896/200