Self-Control is defined by the Meriam Dictionary as restraint exercised over one's own impulses, emotions, or desires".
Self-control and the Holy Spirit
One of the fruits of the Holy Spirit.
The Fruits of the Holy Spirit are perfections that the Holy Spirit forms in us as the first fruits of eternal glory. The tradition of the Church lists twelve of them.
Improving self-control methods and research
Kelly McGonigal defines willpower as "the ability to do what you really want to do when part of you really doesn’t want to do it."
It consists of three elements:
1) I will – the ability to do what you need to do
2) I won’t – resisting temptation
3) I want – Your goals and noble desires
McGonigal recommends increasing willpower though getting proper sleep, exercise and nutrition. Engaging in mindfulness and meditation. Meditation can increase the prefrontal cortex part of the brain which is a center of the brain key to willpower.