Objective: To evaluate effects of early intensive physiotherapy during acute illness on post hospitalization activity daily living autonomy (ADL).Design: Prospective randomized controlled trial of intensive physiotherapy rehabilitation on day 1 to 2 after admission until clinical stability or usual care.Setting: acute care geriatric medicine ward.Patients: A total of 76 acutely ill patients, acutely bedridden or with reduced mobility but who were autonomous for mobility within the previous 3 months. Patients in palliative care or with limiting mobility pathology were excluded. Mean age was 85.4 (SD 6.6) years.Measurements: At admission, at clinical stability and one month later: anthropometry, energy and protein intakes, hand grip strength, ADL scores, and baseline inflammatory parameters. An exploratory principal axis analysis was performed on the baseline characteristics and general linear models were used to explore the course of ADL and nutritional variables.Results: A 4-factor solution was found explaining 71.7 % of variance with a factor “nutrition”, a factor “function” (18.8 % of variance) for ADL, handgrip strength, bedridden state, energy and protein intakes, serum albumin and C-reactive protein concentrations; a factor “strength” and a fourth factor. During follow-up, dietary intakes, handgrip strength, and ADL scores improved but no changes occurred for anthropometric variables. Intervention was associated only with an increase in protein intake. Better improvement in ADL was found in intervention group when model was adjusted on “function” factor items.Conclusion: Physical intervention programs should be proposed according to nutritional intakes with the aim of preventing illness induced disability.