Three-time gold medallist Grant Hackett has admitted that poor health earlier this year almost ended the former world record holder’s hopes of competing at a fourth Olympic Games in Rio de Janeiro.

The 35-year-old swimmer retired from competition after the 2008 Beijing Olympics before he returned to the pool 18 months ago in the hope of making the team for the August 5-21 Games.

“I finished (2015) strongly and was pleased with my fitness and felt like I was making good gains,” Hackett told reporters in Adelaide, where he was finalising preparations for the Australian national championships.

“Then 2016, I hit a standstill with getting bronchitis and being sick in the first couple of months, which was frustrating,” he added ahead of the April 7-14 meet that doubles as selection trials for Rio.

“I needed everything to go right in this preparation to come here and race against these guys. The competition at an Olympic trials is stiff and it steps up that level.

“At my age, six years out of the sport and only 18 months back into it, you have to put your bits and pieces together perfectly.”

The double 1,500 metres freestyle Olympic champion, whose quest for a third successive gold was ended by Tunisia’s Oussama Mellouli in Beijing, has entered the 100m, 200m and 400m freestyle events in Adelaide.

He recognised, however, that his best chance of making the Rio squad was as a member of the 4×200 freestyle team. He won a bronze in the event at last year’s world championships in Kazan.

Hackett, who turns 36 in May, was not the only swimmer making a comeback in Adelaide with two-time 100m freestyle world champion James Magnussen returning after shoulder surgery forced him out of Kazan last year.

Magnussen, however, broke 49 seconds for the first time since the shoulder reconstruction at the New South Wales state championships last month.

The 24-year-old London silver medallist clocked 48.85 seconds leading off his 4×100 relay team, which was a huge boost for his confidence according to national coach Jacco Verhaeren.

“I saw his relief and rightfully so,” Verhaeren told Australian Associated Press. “It showed that he is back on track. From his trajectory from surgery to where he is now, he must be very happy with his progression from successful rehab.”

Magnussen, whose personal best is 47.10, needs to finish in the top-two to qualify for the individual event for Rio, though he will be pushed by Cameron McEvoy, who clocked a world leading 47.56 in February and teenager Kyle Chalmers, who recorded 48.68 last month.

– with Reuters