Also, for everyone commenting about Elena's weight, it's been said before that Nikita has had trouble with lifts, and I've read somewhere that he has had some sort of back injury, which surely doesn't help with lifting anyone, no matter what their weight. It's not necessarily Elena's fault, so don't blame her for factors beyond her personal control.
Yes, he was off training for around 6 weeks in the summer of 2010 due to his back problems - that was part of what lead Tarasova to criticise them for being lazy, because she seemed to think they should have been training through his injuries . I think there was a problem before the 2012-13 season as well. If you see Elena in person, you realise that she is absolutely tiny. Look at the pictures from the banquet at Worlds, you can even see her ribs.