Carlos Gallegos, a physcial therapist at Community Hospital Fitness Pointe, dedmonstrates single-side exercises, which improve strenght on one side. For years, the idea of whole-body health and fitness has been fairly standard. But more fitness experts are extolling the benefits of single-side or unilateral exercise. But though single-side exercise is aimed at isolating a single arm or leg for muscle strengthening, it is not meant to replace exercises that focus on the full body.