John Douillard, author of "Body, Mind and Sport" and a big proponent of nose only breathing has this very interesting statement in one of his newsletters. It's about running but I imagine it pertains to erg'ing as well.
http://www.lifespa.com/newsletter.aspx?newsletter_id=31
In Chi Running, it's the attention to being as relaxed as possible while running that improves performance while minimizing the chances of injury.The experience of "the zone" is the co-existence of opposites where the athlete is running as fast as they can and totally engaged in dynamic activity while simultaneously the nervous system is in a neurological state of peace, calm and repair. During this state of exercise the mind learns how to cope with stress from a calm place and the body learns how to engage in dynamic physical activity while repairing itself at the same time.
I'm interested to know about experiences of erg'ing in the zone, how it feels and any thoughts on how others can get there.