Effect of Aging & Obesity With Exercise Intervention

Change from baseline total droplet area to 12 weeks after initial assessment. Total droplet area is determined by Oil-red-O staining. After staining, the total area (µm2) is analyzed to compare the change after intervention from baseline.

Change from baseline number of lipid droplets to 12 weeks after initial assessment.

Number of lipid droplets determined by Oil-red-O staining. After staining, number of lipid droplets is analyzed to compare the change after intervention from baseline.

Change from baseline CSA to 12 weeks after initial assessment. Chemically skinned vastus lateralis muscle fiber CSA (µm2) is measured by 3 dimensional microscopy. after analysis, CSA is compared the change after intervention from baseline.

Change from baseline Po to 12 weeks after initial assessment. Chemically skinned vastus lateralis muscle fiber Po (mN) is measured by slack test procedure. after measurement, Po is analyzed to compare the change after intervention from baseline.

Change from baseline SF to 12 weeks after initial assessment. Chemically skinned vastus lateralis muscle fiber SF (kN/m2) is Po (kN) normalized by cross-sectional area (m2). SF is analyzed to compare the change after intervention from baseline.

Change from baseline Vo to 12 weeks after initial assessment. Chemically skinned vastus lateralis muscle fiber Vo (FL/s) is measured by slack test procedure. The time required to take up the imposed slack was measured from the onset of the length step to the beginning of the tension redevelopment . For each amplitude of length, the fiber was reextended while relaxed to minimize nonuniformity of sarcomere length. A straight line was presented to a plot of length vs. time, using least-squares regression, and the slope of the line divided by the segment length was recorded as Vo for that fiber.

Vo is analyzed to compare the change after intervention from baseline.

Change from baseline fiber type distribution to 12 weeks after initial assessment.

The MHC composition of single fibers was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).

MHC type distribution is analyzed to compare the change after intervention from baseline.

Change from baseline hand grip strength to 12 weeks after initial assessment. Participants are tested while they were seated, their arms are against their sides, their elbows are flexed 90 degrees. Hand grip Strength is measured in kilograms (kg) using a hand-grip dynamometer. The maximum value from either hand is used for analysis.

Change from baseline Knee extension strength to 12 weeks after initial assessment.

Isokinetic knee extension strength is measured in as peak torque achieved on an isokinetic dynamometer (BTE Primus, BTE tech, MD, USA) at 60° per second.