In recent years there has been increased focus on the importance of quality living. In fact, an informal search of Medline (Pubmed) data base using the search terms “quality-of-life” (QOL) resulted in 65,522 hits involving all publications focused on human beings while an identical search on the Psychinfo data base resulted in 13,506 publications. This research attention is justified because quality-of-life is an important predictor of diverse outcomes including physical and mental health, happiness at work and satisfaction in interpersonal relationships. The limited evidence from clinical trials about the effect of different PA intensity on QoL dimensions is not conclusive, and the majority is originated from high-income countries.