Paralympic rowing champion Pam Relph says she is having to improve her performance level to challenge for Rio.
Relph is part of the GB mixed coxed four crew at this weekend's World Cup in Varese with the heats on Thursday and finals on Saturday.
She will be joined by Grace Clough, Dan Brown and James Fox as the squad continue preparations for 2016.
"In the lead-up to Rio it is getting more difficult to keep your place in the squad," she told BBC Sport.
"But with standards massively rising across the world you can't think your job is done when you get into the GB boat.
"We raced in Varese a few weeks ago and there are so many new crews from different countries, which is exciting to see.
"While we try to stay focussed on our own boat you do look at other people and see what they are doing. You have to know your enemies because we know they are looking at us as well."
Relph is the only remaining member of the four which won gold at Eton Dorney in 2012 and with the boat unbeaten since the victory at the 2011 World Championships, the pressure is on.
"I made my debut at the World Cup in Varese in 2011 and back then I was the novice and the one holding on trying not to mess up for the others," the 25-year-old from Aylesbury added.
"Now I am in the front of the boat with James setting down the rhythm for the others to slot in behind. It is more pressure but I am enjoying it."
You can listen to commentary from the World Rowing Cup II on BBC Radio 5 live sports extra on Sunday from 10:00-14:00 with coverage from 10:40-14:05 via the Red Button and Online