Joggers and runners also gradually become less conscious of themselves as they go—easing the depressive inward dwelling that interferes with the ability to enjoy the simple events of life. They describe letting the rhythm of their effort lead them on—an experience some refer to as the runner's high, a kind of flow. Only those who persevere for several weeks experience it. This state, subtle as it is, often becomes addictive. After a certain amount of consistent exercise, many joggers can no longer go without their 20 minutes of running, even for a single day.
The big mistake that beginners make is to want to go too fast for too long. Truthfully, there is no magic speed or distance. What leads to a feeling of flow is persisting in an effort that you sustain at the limit of your capacities. At the limit, but no further. Research on states of flow has demonstrated this. For a first-timer, the distance will inevitably be short and the steps small. Later the jogger may have to go faster and longer in order to maintain flow, but probably only after he or she has already become addicted.