Track cyclists Glenn O'Shea and Ashlee Ankudinoff claimed the national omnium titles on Friday night, continuing to build their form ahead of the Olympic Games.

O'Shea won four of the six events in the omnium, which will make its Olympic debut next year in London.

Both are making impressive comebacks, with O'Shea not riding at all a year ago because of glandular fever and Ankudinoff overcoming a back-related problem.

Ankudinoff won three of her six races on Thursday and Friday in Melbourne and crucially, one of those wins came in the individual pursuit.

She is among six women vying for four track endurance spots in the London team and the omnium individual pursuit doubled as an unofficial test event.

Selectors will cut the squad further later next month, after another tryout and the national titles in Adelaide.

Ankudinoff, who was a member of the team that won last year's team pursuit world title, had an extended layoff after the Commonwealth Games as she overcame a problem affecting her sciatic nerve.

Another member of that 2010 world title team, Josie Tomic, had to pull out during the omnium nationals on Friday night because of a groin injury.

She will see a doctor over the next few days, but is only expected to be off the bike for a week.

Ankudinoff, from NSW, was a clear winner on 16 points.

WA's Isabella King tied with SA's Annette Edmondson on 21 points and King won the silver medal on a countback.

O'Shea, from SA, won with 12 points and NSW rider Scott Law was next on 17, one clear of SA's Alex Edmondson, who is Annette's brother.

Ankudinoff won the 500m time trial and flying lap events as well as the 3000m pursuit.

She was third in the points, fourth in the elimination and sixth in the scratch race.

O'Shea's won the 4000m pursuit and 1km time trial, as well as the points and elimination.

He was second in the flying lap and sixth in the scratch.

Two-time world junior champion Taylah Jennings from Queensland dominated the women's under-19 omnium, winning four of the six events to successfully defend her title.

NSW rider Tirian McManus beat world junior omnium champion Caleb Ewan to win the men's under-19 title.

McManus led Ewan by one point going into the last round, the 1km time trial.

They raced against each other in the same heat and McManus posted one minute 5.041 seconds to just beat Ewan's 1:05.344.

AAP