OLYMPIC swimmers could be wearing heated jackets that reach temperatures of 50 degrees in Rio after early results showed they can improve lap times by half to three-quarters of a second.
University of Canberra PhD student Courtney McGowan is researching the impact of the jackets to help swimmers keep muscles warm in the marshalling area after British and Australian cyclists used ''hot pants'' to great advantage in London last year.
Ms McGowan said early results were very promising.
''This is swimming at an elite level, one hundredth of a second can make the difference between gold and silver,'' she said.
The first round of testing took six weeks and used 16 teenage swimmers who compete at the national level. The teens swam 100 metre freestyle four times. All the tests were done under race conditions with the lag between warming up and racing averaged to 30 minutes.
''During meets swimmers can be delayed for more than 25 minutes in the marshalling area before racing … they would have already swum laps to warm up and be wearing warm-up tracksuits but the advantage of the heated jacket is that it keeps the muscles warmer for longer.''
Ms McGowan said it was proven that maintenance of heat in the muscles helps performance.
''The most improved times were when the swimmers wore the heated jackets and did a four-minute dry land routine at 20 minutes.''
The four-minute routine included box jumps and stretches while wearing the jacket.
''By wearing the jacket after warm up the decrease in body temperature was about 0.1 degree.''
Ms McGowan said the other advantage of the jacket was that it saved the athlete's energy.
''It's a passive heat so it has the potential to reduce fatigue.''
Liam Barber is a freestyle swimmer. He swam a personal best of 53 seconds after using the heated jacket.
Competitive Olympic swimmers complete the same distance in about 47 seconds.
The 16-year-old said he was considering buying the jacket, which sells for about $250.