Sri Chinmoy: Definitely it increases the speed of unaspiring persons, and also it helps their spiritual purity. There are various reasons for this. The main reason is that running reminds us of our inner goal. Whether we consciously run toward the goal or not, our very feeling that there is a goal helps us considerably. There are many who are not aware of any goal, and they make practically no progress. Again, there are those who are aware of the goal but, at the same time, do not do what is necessary in order to reach the goal.
It is like different types of seekers in a boat. Some of them are observing the sea and helping the pilot; they are excellent seekers. Then there are some who are not helping the pilot in any way; but just because they are in the boat, they are progressing. And there are some who are not in the boat at all. They are like the people who do not run at all, either inwardly or outwardly. So, if one can run, then unconsciously if not consciously, one will be aware of one's progress, and this awareness is nothing short of an increase in purity and speed.