If you’ve ever been the caregiver for an impaired elderly loved one, you know where your focus lies almost every minute of every day—with the person you are caring for. My mom is the full-time caregiver for my dad, who’s had Parkinson’s for the past 12 years. Parkinson’s is a slow-growing disease that causes uncontrolled shaking, an inability to move and, at the later stages, dementia. My dad is 170 pounds; my mom weighs 95 pounds. My dad needs to be lifted out of bed, needs help to stand up and requires assistance for the few brief steps he takes with his walker to the bathroom, kitchen or living room. He needs to be bathed and shaved, and needs help with brushing his teeth. It’s a struggle to dress Dad, as he doesn’t have control of his muscles to help Mom put on his Depends, pants, shirt, socks and sneakers. Exercise can help Dad sustain what limited range of motion he has, so Mom cues him through his daily exercise routine. She also sings songs with him and has him recite...