Magnussen finished the 2014 long course season with a crippling back complaint that often meant he struggled to get out of bed in the mornings and has since quit training with his coach Brant Best as he reshapes his program for a two-year push to the 2016 Rio Olympics.
The 23-year-old dual world champion is yet to confirm his official new coach, believed to be former Port Macquarie squad teammate Mitch Falvey, but is back in the pool and busy preparing for his world title defence in Kazan next year.
But Magnussen’s major goal is to win the gold medal in Rio, with the 46.91 second world record set by Brazil’s Cesar Cielo during the supersuit era also a mark he wants to dismantle.
In an interview with the BBC, Magnussen revealed he’d been chasing a 46 second 100m freestyle swim since he was 16.
“I can achieve it,” Magnussen said.
“It’s a realistic goal of mine that before the end of my career I’d like to drop below that 47 second barrier.
“I remember when I was about 16 I said to my coach ‘I’d love to do something nobody else has ever done.’
“He said ‘well 47 seconds.’ I said ‘yeah do you think people can swim 46 seconds?’ He said ‘I don’t know but you could always give it a try.’