Eva goes roller-skating every day, partly for exercise and partly because of the feeling she experiences when she is skating. She feels euphoric and completely engrossed in the activity, and she often loses track of time. What is the word for what Eva experiences?

Flow.

Explanation:

Eva feels euphoric and completely engrossed in the activity, and she often loses track of time, Eva experiences flow. According to Mihály Csíkszentmihályi, a positive psychologist, people who are completely immersed in an activity as Eva is when roller-skating experience flow. It is a loss of self-awareness and an immersion in the activity without minding anything but the activity itself. Flow can be experienced through different activities for different people. It can be felt when practicing some sport or when painting or writing.