Testing a self-determination theory-based teaching style intervention in the exercise domain JEMMA EDMUNDS 1 * , NIKOS NTOUMANIS 2 AND JOAN L DUDA 2 1 Applied Research Centre in Health and Lifestyle Interventions, Coventry University, UK 2 School of Sport and Exercise Sciences, University of Birmingham, UK Abstract Drawing from self-determination theory (SDT), this study examined the effect of an autonomy supportive, well structured and interpersonally involving teaching style on exercise class participants’ psychological need satisfaction, motivational regulations, exercise behaviour, behavioural intention and affect. Female exercise class participants enrolled in a 10-week exercise program were exposed to an SDT-based (i.e. SDTc; n ¼ 25) or typical (i.e. control group; n ¼ 31) teaching style. The control condition reported a significant decrease in autonomy support, amotivation and behavioural intention over time. In addition, they reported a significant increase in competence and introjected regulation. Compared to the control condition, the SDTc reported a significantly greater linear increase in structure and interpersonal involvement, relatedness and competence need satisfaction and positive affect. Attendance rates were significantly higher in the SDTc. SDT-based social-contextual characteristics and psychological needs predicted autonomous regulations; all these variables collectively predicted adaptive outcomes. Copyright # 2007 John Wiley & Sons, Ltd. Although regular physical activity is conducive to physical and psychological health (Biddle & Mutrie, 2001), less than 30% of adults meet current physical activity recommendations (e.g. Department of Health, 2004). To increase the number of people that engage in, and maintain, a physically active lifestyle, the social psychological factors conducive to exercise adoption and adherence need to be delineated. Self-Determination Theory (SDT; Deci & Ryan, 1985), a contemporary theoretical perspective of human motivation, appears to hold promise for elucidating the socio-contextual and psychological factors influencing participation in physical activity. BASIC PSYCHOLOGICAL NEED SATISFACTION AND A MOTIVATIONAL CONTINUUM SDT assumes that all humans possess three basic psychological needs that are fundamental to the nature and quality of engagement in any given domain (Deci & Ryan, 1985), a proposition supported by previous research (e.g. Sheldon, Elliot, Kin, & Kasser, 2001). A need for autonomy reflects a desire to engage in activities of one’s choosing and to be the origin of one’s own behaviour (deCharms, 1968; Deci & Ryan, 1985). A need for relatedness involves feeling connected to others, European Journal of Social Psychology Eur. J. Soc. Psychol. 38, 375–388 (2008) Published online 18 September 2007 in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/ejsp.463 *Correspondence to: Jemma Edmunds, Applied Research Centre in Health and Lifestyle Interventions, Coventry University, Coventry, UK. E-mail: j.edmunds@coventry.ac.uk Copyright # 2007 John Wiley & Sons, Ltd. Received 13 February 2007 Accepted 18 July 2007