Well, I'm not a racer, so take this as my 2 cents.... I can't think of any time on the bike that I would be standing straight up and running! I don't do it in spin and it's just unsafe for your knees. Any time I am out of the saddle I am in the traditional climbing position. I might move around a little, but not straight up.
My son raced for 4 years and I can't think of any time I saw him running in a standing position.