The major purpose of this study is to establish the use of daily step counts as inexpensive, easy to measure marker for frailty and sarcopenia in an inpatient population of older adults.

The total time involved to complete study procedures will be between 2-3 hours at your enrollment and up to 10 minutes at your discharge. Investigators will invite participants to enrol in this study at your admission and discharge days.

Firstly, Investigators would like to collect some demographic data, including participants age and gender.

Then Investigators will ask participants to check their blood pressure and heart rate, weight, height and Body Mass Index.

Also Investigators will collect participant's medication List and Past Medical History.

Then, Investigators would like to ask participants to carry special device on their mid-thigh. It's called 'ActivPAL' and a trained research assistant will fit it on participant's dominant leg. This device has ability to detect the joint angle of participant's thigh to capture lying, sitting, standing, and stepping activities.

Then Investigators will proceed to ultrasound test. Participants will be asked to lay down on the bed with their legs supported by a pillow. Then a study physician will use ultrasound to measure participant's leg muscles. Three measurements will be taken for each participant.

After that participant will be asked to do a "Grip test". Participant will be asked to squeeze special device, called dynamometer, using your dominant hand. Each participant will be asked to make three attempts with half a minute break between each measurement.

Participant will be asked to walk 10-15 meters in order to measure their gait speed.

Impedance measures of body composition will be performed using an automatic scale.

At the end Investigators will ask you to measure participant's body structure, using skinfold/caliper device.

At participant discharge Investigators will remove 'ActivPal' sensor from their leg that was fitted at enrollment.

Inclusion Criteria:

• be 65 years of age or older
• be admitted in ACE Unit

Exclusion Criteria:

• be less than 65 years of age
• be nonambulatory
• be diagnosed with end-stage organ failure (end-stage COPD, renal failure requiring dialysis, end-stage heart failure)

Study population will be recruited consecutively from the Acute Care of the Elderly Unit at SPH.