Consciously increasing tension in a muscle can help people carry out unpleasant tasks and avoid unhealthful foods.

Firming one’s muscles [e.g., clench fist, contract calves, tense bicep] can help firm willpower and firmed willpower mediates people’s ability to withstand immediate pain, overcome tempting food, consume unpleasant medicines, and attend to immediately disturbing but essential information, provided doing so is seen as providing long term benefits.

From Firm Muscles to Firm Willpower:
Understanding the Role of
Embodied Cognition in Self-Regulation
Journal of Consumer Research 2010

University of Singapore

Booth School of Business University of Chicago