[1] Italian Agcy Dev Cooperat, IL-9135400 Jerusalem, Israel
[2] Anglia Ruskin Univ, Cambridge Ctr Sport & Exercise Sci, Cambridge CB1 1PT, England
[3] Univ Barcelona, Fundacio St Joan Deu, Parc Sanitari St Joan Deu, Barcelona 08005, Spain
[4] South London & Maudsley NHS Fdn Trust, Physiotherapy Dept, Denmark Hill, London SE5 8AZ, England
[5] Kings Coll London, Inst Psychiat Psychol & Neurosci, Hlth Serv & Populat Res Dept, Crespigny Pk, London SE5 8AF, England
[6] Med Univ Vienna, Ctr Publ Hlth, Dept Social & Prevent Med, A-1300 Vienna, Austria
[7] UCL, Dept Behav Sci & Hlth, London WC1E 6BT, England
[8] CNR, Neurosci Inst, Aging Branch, Via Giustiniani 2, I-35128 Padua, Italy