This study examined the effect of motivational primes on participants (N = 171) 
during a cycling task. Relative to participants primed with a controlled motivational 
orientation, it was hypothesized that participants primed for autonomous motivation 
would report greater feelings of enjoyment, effort, and choice in relation to the 
cycling activity and report greater exercise intentions. Members of the autonomous prime group were expected to exercise for longer, at a greater percentage 
of their heart rate maximum, and report lower levels of perceived exertion than 
those in the controlled prime condition. It was found that, relative to participants 
in the controlled prime group, those who received the autonomous prime enjoyed 
the exercise more, exercised at a greater percentage of heart rate maximum, and 
reported a lower rating of perceived exertion. Furthermore, participants experiencing the controlled prime exercised for less time and had lower intentions to 
exercise than did other participants. Results highlight the importance of automatic 
processes in activating motivation for exercise.