“…In the original version of this manipulation, participants wrote for 20 min on 4 consecutive days about a future in which they imagine themselves in the best possible condition and circumstances. The BPS manipulation was found effective in increasing PA, well-being and physical health (Austenfeld, Paolo, & Stanton, 2006;Harrist, Carlozzi, McGovern, & Harrist, 2007;King, 2001;Sheldon & Lyubomirsky, 2006). These studies did not specifically assess the potential of the BPS manipulation to induce positive expectancies, although preliminary evidence for an effect on optimism was provided by King (2001).…”