Psychology is applied to all other social sciences and other various fields. It is the study of behaviour, which also affects all other sciences and so on.
Just set up things you want to do on a certain day like Monday you do legs and so forth
If you have a low self esteem you think lowly of yourself which often gives you a more negative outlook yourself and everything you do. This can severely damage your mental health. Have bad mental health can lead to depression, anxiety, and other mental illnesses and people stop wanting to take care of themselves as they go into depressive episodes.
People with high self esteem generally have a more positive outlook which creates a better relationship with themselves and people around them. This improves their mental health which provokes them to want to take better care of themselves.
