What makes rowing popular with elite athletes and CrossFitters is exactly what many in the general fitness population dislike about it: your weaknesses cannot be hidden on the rowing machine. It is a human polygraph of physical and mental performance. Stroke for stroke, you are provided with feedback that both reveals any weak spots and very visibly demonstrates the relationship between performance and proper technique.  —Angela Hart, "Rowing Technique," CFJ

As a 2012 Olympic silver-medalist rower, Krista Guloien has a thing or two to say about the erg.