Frailty is an age-related condition that compromises quality of life and independence in older adults. Physical exercises plays a key role in this context, as regular exercise offers significant health benefits to frail seniors. Technology can support participation in physical activity at home. Recently, social robots, often used as engaging companions, have emerged as promising tools for safe and motivating training. This paper presents the use of the Alpha Mini robot as a personal fitness coach for older adults. It is equipped with a computer vision module, trained on a custom dataset, to recognize and evaluate the correctness of exercises through a deep learning model.