We hypothesized that early exercise rehabilitation for patients with severe sepsis or septic shock would decrease their functional disability and cognitive impairment. We plan to enroll patients with severe sepsis and septic shock who admitted an urban teaching hospital in Seoul, South Korea via ER. We will randomize those subjects into the intervention group which will take a standardized rehabilitation with routine clinical care for sepsis and the control group which will take routine clinical care for sepsis. And, we plan to assess their functional activity using ADL, IADL and SF-36, and cognitive function using MMSE at the time of enrollment, 28 days, and 6 months later.

Inclusion Criteria:

1. age ≥20;
2. confirmed or suspected infection;
3. two or more among 1)-4) 1) body temperature >38˚C or <36˚C 2) heart rate >90/min 3) respiratory rate >20/min or PaCO2<32 mmHg 4) WBC >12000/mm3, <4000/mm3, or band forms >10%;
4. within 48 hours after arriving ER

Exclusion Criteria:

1. severe functional disability before admission;
2. central nervous system infection;
3. contraindication for exercise rehabilitation according to the investigators' decision;
4. severe medical illness or mental problem or laboratory abnormality which can confound the results;
5. pregnancy