The Appleby Bermuda Half-Marathon Derby is wide open with a new men’s and women’s champion to be crowned this year.

Lamont Marshall and Ashley Estwanik will not be defending their titles and it is anyone’s guess who will lay claim to their vacant crowns.

Marshall, who shaved three seconds off his own national 3,000-metres record (8min 05sec) at the Jamaica International Invitational at the weekend, confirmed several weeks ago that he will not be running.

According to the runner’s father and coach, Larry Marshall, any chance of last year’s winner reconsidering his decision has been dashed because of a stomach bug.

Estwanik, who finished third in her age group and 119th overall at the Ironman 70.3 Chattanooga in Tennessee at the weekend, has opted to compete in the Sinclair Packwood Memorial Race for Team Madison rather than bid for a seventh Half-Marathon Derby title.

Her husband, Chris Estwanik, the six-times champion and race record holder for both courses confirmed yesterday that he will not compete again this year because of injuries to his legs and hip.

“Unfortunately, the tear in my hip and multiple breaks are too painful,” Estwanik said. “Additionally, every medical professional has strongly advised against me even lining up on Wednesday so I’ve decided to make the responsible decision as opposed to the emotional one.”

Estwanik is tied with Ed Sherlock with six wins and three behind Kavin Smith’s record of nine.

“Gutted to miss it yet again as it is without a doubt my favourite day of the year,” Estwanik added. “Best of luck to everyone!”

Promising triathlete Tyler Smith, who finished fifth last year, has been ruled out through school exams at the University of Leeds in England.

Among the top contenders in the men’s field are Jay Donawa, Chayce Smith, Evan Naude, Chris Harris, Jamie Fraser and Tim Price.

Naude, who finished third last year, is ranked the highest among the contenders going into the 13.1-mile race while Donawa has placed among the podium finishers on numerous occasions. Two previous winners are among a trio of contenders in the women’s field.

Deon Breary and Victoria Fiddick, winners in 2009 and 2011, are the favourites to claim Estwanik’s vacant title along Karen Smith, the mother of triathlete Tyler Smith.