The rowers at IC are immense, you will not find the 1st 8 anywhere but Putney. They may got to their occasional materials lecture. But yes, if your serious about it the training is hell. I heard from a medic rower who tried IC rowing that its 4 maybe 5 times a day you train.
It is widely regarded that the IC rowing team is the best uni team. Hardly surprising if the 7 of the 1st 8 are Italian nationals and the 8th is GB national.