Soaring temperatures have gripped parts of southern and northern India in an extreme heat wave which.
The Russian twins have monopolised South Africa's ultra-distance events, including the Two Oceans Marathon, for the past five years.
Elena won the celebrated 89,9km Comrades last year in a time of 6hr:13min:04sec, a mere second ahead of her sister.
Capetonian Farwa Mentoor, who has consistently been finishing in the top 10 for the past five years, was the first South African woman home in 6:38:41.
In the men's section, Zimbabwean Stephen Muzhingi is hoping to complete a hat-trick of titles. But Ludwick Mamabolo, who finished second last year, is confident that he will end the monopoly of the Zimbabweans and Russians in "The Ultimate Human Race".
"The weather is perfect in Durban and I'm keeping my fingers crossed that it will still be good on Sunday," Mamabolo said.
"I have completed my training and am looking forward to becoming the first South African winner since Sipho Ngomane in 2005."
Another South African to watch on Sunday is Bongmusa Mthembu, who, like Mamabolo, is from Mr Price Athletics Club. Mthembu finished fourth last year but ended up third after Sergio Motsoeneng was disqualified for cheating.
Martin Ngwenya, one of the Mr Price club's managers, who is also Mthembu's training partner, said: "We are convinced that one of our members will win the title this time round."
Meanwhile, top boxing promoter Branco Milenkovic has donated R44500 to television and radio presenter Kwena Moabelo, who will run the Comrades to raise money for two charitable organisations in his home town of Seshego.
Moabelo said: "I'm also happy that Gauteng MEC for sport Lebogang Maile has also pledged to assist me."
The race, which is an up run from Durban to Pietermaritzburg this year, starts at 5.30am.