Abstract
When people are autonomously regulated they experience a heightened sense of vitality, whereas controlled regulation diminishes vitality (Ryan & Deci, 2008). Research shows that autonomous regulation helps people override self-control depletion (Muraven, 2008). However, from a resource allocation perspective (Beetie & Lane, 2012) greater autonomous motivation may prompt immediate access to limited energy reserves, but deplete self-control resources such that performance will suffer more distally. The purpose of this study was to investigate if heightened autonomous motivation would be associated with better self-control performance in the short term, but worse performance in the longer term. Participants (N = 72) completed two, sequential, sub-maximal (50%) endurance isometric handgrip trials. Before the first trial they were provided with autonomously supportive (n = 37) or controlling (n = 35) instructions. As expected, those who received autonomy support prior to the first trial performed better than controls (p = .012, d = 0.62). However, on the subsequent trial, the autonomy support group fared significantly worse than controls (p = .001, d = 0.82). Thus, autonomous motivation may stimulate vitality but it comes at a cost in that motivated utilization of energy reserves eventually leads to greater resource depletion. Results have important implications for self-regulated tasks such as endurance sports that involve protracted investment of self-control over time.
