This time of the year is the hardest time to stay motivated to run. It’s cold, it’s windy, it’s wet, and sometimes it’s even icy. But the Shamrock Run, which many Portlanders consider the unofficial start to race season, is right around the corner, and if you’re planning on putting in some mileage, training needs to start NOW. You may or may not know that in addition to being a runner, I’m a group exercise…