It is clearly shown that patients in the Intensive care Unit (ICU) with severe sepsis or multi organic failure are very susceptible to develop neuromuscular complications. That can be attributed to a hyper catabolic state, general inflammation and immobilization. This can leads a significant muscle wasting, polyneuropathy and/or myopathy. These alterations have been defined with the term Intensive Care Acquired Weakness (ICUAW) and can leads important functional squeals and impaired quality of life for months, years and in some cases irreversibly.

To overcome these complications, early activation by physiotherapy becomes an important tool. This type of treatment has been show to be feasible, safe and improves the functional capacity of patients. In addition to a reduction in the duration of ICU and hospital stay and improved quality of life for patients.

The objective of this study is to demonstrate that the early and active physical activity in patients with severe sepsis can limit the loss of muscle mass and complications related to this type of damage.

Procedures: Patients or relatives will be asked to participate in the study. If a positive response is done, patients will be randomized in an intervention or control group.

A baseline evaluation will be performed during the first day of study admission. That includes a physical exploration, electrophysiological studies, skeletal muscle histological/biochemical evaluations and monitoring of blood biomarkers and others clinical outcomes will be registered.

Intervention will be divided in a morning and afternoon times, patient will be positioned in chair or bed and mobilized by physiotherapist. As usual, all patients will be attaining manual mobilization for 20 minutes twice a day. Only for intervention group, additional cycle-ergometer exercise will be performed for 30 minutes at better performance achieved and tolerated for patient. All vitals parameters will be strictly controlled before, during and after intervention.

The same baseline evaluation will be repeated after day 7 and clinical outcomes will be registered until ICU discharge.

Inclusion Criteria:

• Hemodynamically stable patients.
• Admitted to ICU for sepsis or MOF (multiple organ failure) or who developing during their ICU stay within the first 24 hours of the ICU admission.
• With an expected ICU stay of at least 7 days.

Exclusion Criteria:

• Patients without approved consent.
• Patients with a known neuromuscular disorder before ICU admission.
• Moribund patients.
• Severe metabolic/hemodynamic instability despite pharmacological support.
• Having conditions that impair evaluation techniques or intervention methods.