World 800m champion Eunice Sum of Kenya believes she has no intention to prove to anybody her ability over the two-lap race in 2015.

Sum, 26, will be making her third appearance at the World Championships in Beijing, China in August if at all she proves her critics wrong and secure a berth in the explosive Kenyan trials.

To do that, the World number one and also Commonwealth Games 800m champion will not be resting on her laurels but will cut short her holiday so as to start her training in the Kenya cross country season.

"I have to be at my best level. It will be tough and the Russians will come back stronger in bid to silence me. But the important thing is to run my own race and not focus on anything beyond myself.

"In Beijing and the entire 2015 season, focus will be on me, but I have weathered that storm since winning in Moscow in 2015 worlds," she said.

The cloud surrounding doping in the country among elite athletes is however, least of Sum's worries, despite sharing the same agent with busted Chicago Marathon Champion Rita Jeptoo. Both athletes are under the Dr. Rosa and Associates training camp in Kaptagat.

Instead, she is focusing her energies to scheme on best way to retain her title at the Worlds and the Diamond League Trophy.

"I need to start by improving on my endurance and that is why I will be competing at this year's cross country season. It's aimed at helping me keep my fitness on check after the track running season was closed.

"I know this will be the best preparations ever when the new season starts next year," she said.

Sum made her international championship debut in the 800 meters at the 2010 African Championships in Athletics in Nairobi, but failed to make the final.

In 2011, she set a personal best time of 1:59.66 in finishing second over 800 m at the Kenyan championships.

This performance qualified Sum for the 800 m at the 2011 World Championships in Athletics in Daegu, South Korea, where she reached the semi-finals.

Sum won a silver medal - her first medal in international competition - in the 800 m at the 2012 African Championships in Athletics in Porto-Novo, Benin.

She ran a personal best of 1:59.13 in the final, finishing two hundredths of a second behind Burundi's Francine Niyonsaba.

"In any championships, I always prepare well. At both the world championships and Club Games, I had set my goal to win gold. In Moscow nobody gave me a chance and I surprised many.

"But the issue of surprise is not there anymore and I just want to run my race and that is why it is important to start my preparations for the World Championships in Beijing early," she said.