In selecting men's running clothing, consider the conditions in which you run; whether you run outdoors or on a treadmill, during the day or at night, and what the weather is like for your season. This can help you decide whether you need wind- or water-resistant fabric, long or short sleeved running shirts, and more. Look for a length and fit that is comfortable for you, and experiment with different styles to find what suits you best in different running conditions.