I just started Shock Wave this week, and I'm having good lifts so far. I'm excited to see the results after a month. I just have a question about performing a specific exercise.On 'Shoulders, Tris' day one of the warm-ups is 'Chest Stretch'. Is there a particular stretch, or am I just supposed to pick my favorite static chest stretch? I know this is a small concern, but I figured, in a program with this much research behind it, there's a good reason for every exercise.