Sri Chinmoy: It is always advisable to concentrate while running a marathon. If you meditate, then you will feel that you are either on the top of a snow-capped mountain or at the bottom of the sea. That is the very highest type of meditation, but that will not help your running. But if you concentrate on running, then at every moment you will be able to regulate your steps and your forward movement. Also, discouraging, destructive and uncomely thoughts will not be able to lower your consciousness. If your consciousness is not lowered, then naturally you will run faster.
Before running, however, meditation is good to make the mind calm and quiet so that wrong forces do not enter. When you meditate, your mind acquires some poise. Then, while you are running, if you can bring forward this poise, it will help you overcome the mental frustration that often comes while running long distances. When you are running long distances, all kinds of frustrating thoughts will come and make you feel that what you are doing is useless. Or the mind will say, "Oh, this is boring," and you will not want to take one more step. But if you were able to meditate earlier in the day, then you will have acquired some solid inner strength that will carry you mile after mile. Also, meditation teaches you how to empty your mind of thoughts. And if you can keep thoughts out of your mind while you are running, it will help you tremendously — far beyond your imagination. At that time a new creation will be able to dawn inside you, and this will give you added inspiration and receptivity.
But while you are actually running, it is better to concentrate rather than meditate. Another thing you can do is chant or sing spiritual songs soulfully and powerfully. This will also help keep your mind from becoming tired and frustrated and interfering with your running.