February 10, 2009 | 11:06 p.m. CSTFrom left, Bob Martin, Dan Heaviland and Kris Hagglund stretch after an early morning run. The three men are part of a large group of all-weather runners who begin running at 5:30 a.m. on Tuesdays and Thursdays. "This is the definition of nuts," Martin said, referring to running in 20-degree weather. When asked about his reason for running so early in such cold weather, Martin said, "Partly for getting a run in before work but mostly because the people are so cool." The group meets at an access point to the MKT Nature Trail on Forum Boulevard.