What Should I Do Before My Workouts?
Always perform a dynamic warm up for before running and cross training, which includes exercises like arm circles, neck rolls, leg swings, and hip rolls. Check out this awesome lunge warm-up sequence and the leg-swings too.
And What Should I Do After My Workout?
Static stretching, or performing stretches you hold for 30 seconds or longer, should only be practiced after your workouts, if at all. Instead, I prefer a 10 minute walk along with a cool down routine.