Question - is their another Olympic sport that consistently uses every muscle in your body?
Off the top of my head:
Water Polo Swimming Judo Wrestling Gymnastics Kayaking Pole Vault High Jump Long Jump Triple Jump Javelin Discus Hammer Toss Shot Put Hurdles Volleyball Basketball Weightlifting
Rowing is a great and physically grueling sport -- don't get me wrong -- but your extraordinary claim that it is "easily the most difficult sport in the Olympics" requires extraordinary support.