“…The Theory of Self-Determination (TSD) (Ryan and Deci, 2000b) is one of the most well-known theories and considered one of the most important theories of contemporary motivation and used to investigate motivational processes in several contexts in the last decades, being sport and physical activity one of these (Deci et al, 1991). Its central premise is that motivation leads to variations between the amotivation and the intrinsic motivation (Simões & Alarcão, 2013), with subjects tending to participate more in activities when they regulate their behaviour towards more selfdetermined forms, that is, more intrinsically motivated (Deci & Ryan, 2002;Pires, Cid, Borrego, Alves, & Silva, 2010). The TSD refers to the existence of a spectrum or continuum ( Figure 1) that encompasses several forms of motivation, ranging from the lowest level (amotivation, external regulation and introjected) to the highest (identified, integrated regulation, and intrinsic motivation, Vallerand et al (1992) and Vallerand (2007).…”