A study from a team of researchers, using a large population, found depression to be related to increasing moderate-to-vigorous intensity physical activity and decreasing sedentary time among overweight and obese adults.

Results suggested that being sedentary for large portions of the day may be more hazardous with respect to depression for adults who are overweight or obese compared with those who have a healthy body weight.

Therefore is important for people working in physical activity to promote the psychological benefits it can bring in terms of depression and other health conditions. Note that this study is a useful reference, although a limitation is that it is a snapshot in time, rather than evidence of causal relationships.