The decrease in functional abilities can negatively influence quality of life and autonomy in elderly people, and physical exercise plays a crucial role regardless of the type. Among the latter, also due to the COVID-19 pandemic, outdoor exercise and telecoaching are settings that have been widely implemented. Hence, the aim of this study was to investigate the effectiveness of a sustainable training program combining supervised outdoor exercise with telecoaching on physical performance in elderly people. A total of 60 participants were recruited and divided into two groups: a trained group (TG) and an untrained group (UG), based on their participation in an 8-week sustainable training program consisted of five sessions/week, which included two sessions/week of supervised outdoor exercise and three sessions/week of telecoaching. Participants were evaluated before and at the end of the training program using the handgrip test, Timed Up and Go (TUG) test, short physical performance battery (SPPB), and Tinetti scale. In the TG, we found a significant improvement in the following tests: right handgrip (p < 0.001); left handgrip (p < 0.001); TUG (p < 0.001); SPPB (p = 0.01); and Tinetti scale (p = 0.006). A detailed analysis of the SPPB and Tinetti scale showed the lack of significant changes in walking ability: gait speed (p > 0.05) and walking parameters in the Tinetti scale (p > 0.05). Based on our results, we suggest that a sustainable training program combining supervised outdoor exercise with telecoaching could be effective in the elderly population for improving balance capacity and strength.