Muscle function and strength measures will be conducted before and after the interventions, with the exception of the 400-meter walk test, which will also be performed at the study midpoint (12-weeks). Gait speed will be assessed using the fast 20-meter and 400-meter walk tests. The 400-meter walk tests was originally developed in Health ABC and used by our group in the CLIP and LIFE studies. Participants are asked to walk 10 laps of a 40-meter course (20 meters out and 20 meters back) per standardized instructional script. The reliability and validity of the 400-meter walk test are excellent and performance is an important prognostic indicator for total mortality, cardiovascular disease, and mobility disability in older adults. Physical performance will be assessed using the expanded Short Physical Performance Battery (SPPB). The expanded SPPB consists of 5 repeated chair stands, standing balance (semi- and full-tandem stands and a single leg stand for 30 seconds), a 4-meter walk to assess usual gait speed, and a narrow 4-meter walk test of balance (walking at usual pace within lines of tape spaced 20 cm apart).Scores for the traditional 0-12 point SPPB can also be obtained from these tests. Physical performance will also be assessed using the Timed-Up-and-Go (TUG). TUG measures the time a person takes to stand up from a standard chair, walk 3 meters, turn, walk back to the chair, and sit down again. A practice trial is given, followed by two timed trials and the results of the timed trials are averaged. Stair climbing time will be assessed by measuring the fastest time achieved to climb 4 steps on a 4-step staircase (test will be performed 2 times). Lower extremity muscle power will be measured using the Nottingham Power Rig, a safe, convenient method for assessing power output from the lower limb which has been used reliably in older adults. Participants will sit in a chair and unilaterally depress a foot lever attached to a flywheel as hard and as fast as they can. Power output, derived from the acceleration of the flywheel, will be recorded in Watts. Power will be averaged for each leg following 5 trials at maximal effort. Participants that have had a unilateral hip or knee replacement should not have that side tested. Participants who have had eye surgery (e.g., cataract surgery) within the past month should not be tested. Lower extremity muscle strength will be measured using an isokinetic dynamometer (Biodex/KinCom) at one speed (60°/sec) with the participant sitting and the hips and knee flexed at 90°. The dynamometer will be adjusted for each participant and all adjustments will be recorded to duplicate the position for subsequent assessments. Start and stop angles will be set at 90° and 30°. Participants will be asked to extend the knee and push as hard as possible against the resistance pad. Strength is expressed as peak torque in Newton-meters (Nm). The best performance of 3 trials will be selected for each side, and the averages of the left and right leg will be used in analyses. Grip strength will be measured twice in each hand to the nearest 2 kg using an isometric Hydraulic Hand Dynamometer (Jamar, Bolingbrook, IL) and the mean value from the stronger hand used. Participants will be excluded from performing the test if they report hand-pain or recent hand or wrist surgery.