Inclusion Criteria:  Frailty score of 3 or more (based on Johns Hopkins Frailty Assessment). Age 55 and older Elective Lumbar Spine Fusion Surgery  Exclusion Criteria:  Emergency surgery Time-sensitive surgery Spine trauma, tumor, or infection Physical condition that limits exercise: Lower extremity amputation, hemiplegia or hemiparesis, stroke with residual weakness, symptomatic severe cardiac disease (for example: severe aortic stenosis, unstable angina) Patient refusal Severe cognitive dysfunction preventing participation or consenting.