2.3. Body Composition and Physical Function

After measuring the participants’ height and weight using a body composition analyzer (Inbody 370, Biospace, Seoul, Korea), body fat mass (BFM) percentage was subsequently measured using the bio-electrical impedance analysis method. Waist circumference (WC) was measured to the nearest 0.1 cm at the level of the umbilicus using a flexible plastic tape while the participant was standing. Body mass index (BMI) was calculated using the following formula: Weight (kg)/heigt² (m²) × 100. Two days before the body composition measurement, participants were instructed to avoid any physical activity other than routine daily activity. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using a mercury sphygmomanometer (HICO, Tokyo, Japan) after a 10-min rest. The physical function test used the maximum value after measuring each twice for four items. Measurement items and methods were as follows: Grip strength was measured using isometric dynamometer (TKK-5401, Japan) for the dominant arm; time up and go (TUG) was measured based on the time needed to stand up from a standard armchair, walk 2.44 m, turn, walk back the 2.44 m, and sit down again at the fastest speed; walking speed was measured at 4-m walking time, except for 1.5 m each in acceleration and deceleration zones respectively; the 6 min walking was measured based on the distance traveled for 6 min in a 20-m straight zone, where participants were asked to walk as far as possible for 6 min; and physical activity was measured using a Fitmeter (Fit. Life, Seoul, Korea), a 3-axial accelerometer. High correlation (r = 0.947) and high explanatory power (R² = 0.897) were observed between the signal vector magnitude of the Fitmeter and the count-based values measured by the ActiGraph (wGT3x-BT, Pensacola, FL, USA) [27].