Eustress

A form of stress associated with positive feelings and healthy bodily states. Eustress is a stress response towards stimuli/targets appraised as harmful, threatening, and challenging but within one’s confidence and/or capability

Reference:
Lazarus, R. S. (1993). From psychological stress to the emotions: A history of changing outlooks. Annual Review of Psychology, 44(1): 1-22. doi: 10.1146/annurev.ps.44.020193.000245