Antony James says he is on course to try and qualify for the Rio Olympics.
The 26-year-old Plymouth Leander swimmer missed the 2014 Commonwealth Games after a shoulder injury hampered him at the British trials.
"I've never trained so fast," said James, who is the top-ranked 100m butterfly swimmer in the UK after winning the British universities title.
"I'm reasonably confident, but I would just say that because I do train very hard," he told BBC Radio Devon.
James, who raced at London 2012 and won silver at the 2010 Commonwealth Games, says he is only focused on this month's British short course championships and April's Olympics trials.
"I went to the London Olympics and I found that season everything was focused towards that performance at trails and the performance at the Olympics," he said.
"I'm finding it's the same sort of thing happening again with Rio, everyone is very excited and training very hard and it's a very positive atmosphere to be around.
"We've got such a good squad of people here at Plymouth Leander, they put everything into training and they're all amazing swimmers, so having that day-to-day it does boost your confidence levels, as you know you're training with the best and you're training as the best."