A statistical analysis showed that in both groups, higher levels of physical activity corresponded to higher self-efficacy and lower levels of depression and fatigue. But when the researchers controlled for the influence of self-efficacy on depression and fatigue, they found that the effect of physical activity on both depression and fatigue was significantly reduced.
This suggests, McAuley said, that physical activity influences depression and fatigue by increasing self-efficacy.
"What we're showing is that the relationship between physical activity and reductions in fatigue in breast-cancer survivors and people with MS can be explained in part by the effect of physical activity on mastery experiences," he said. "That sense of accomplishment, or situation-specific self-confidence, serves to reduce depression, which in turn reduces fatigue." Increased self-efficacy also has a direct effect on reducing fatigue, he said.
Physical activity programs can be designed to effectively enhance self-efficacy and, in turn, well-being, McAuley said.
Source: University of Illinois at Urbana-Champaign